--event <event> event selector. use 'perf list' to list
available events
--comm show the thread COMM next to its id
--tool_stats show tool stats
-e, --expr <expr> list of events to trace
-o, --output <file> output file name
-i, --input <file> Analyze events in file
-p, --pid <pid> trace events on existing process id
-t, --tid <tid> trace events on existing thread id
--filter-pids <float>
...
As shown above, the -f option does not work at all.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-10-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Yunlong Song [Thu, 2 Apr 2015 13:47:17 +0000 (21:47 +0800)]
perf timechart: Support using -f to override perf.data file ownership
Enable perf timechart to use perf.data when it is not owned by current
user or root.
Example:
# perf timechart record ls
# chown Yunlong.Song:Yunlong.Song perf.data
# ls -al perf.data
-rw------- 1 Yunlong.Song Yunlong.Song 5471744 Apr 2 15:15 perf.data
# id
uid=0(root) gid=0(root) groups=0(root),64(pkcs11)
Before this patch:
# perf timechart
File perf.data not owned by current user or root (use -f to override)
# perf timechart -f
Error: unknown switch `f'
usage: perf timechart [<options>] {record}
-i, --input <file> input file name
-o, --output <file> output file name
-w, --width <n> page width
--highlight <duration or task name>
highlight tasks. Pass duration in ns or process name.
-P, --power-only output power data only
-T, --tasks-only output processes data only
-p, --process <process>
process selector. Pass a pid or process name.
--symfs <directory>
Look for files with symbols relative to this directory
-n, --proc-num <n> min. number of tasks to print
-t, --topology sort CPUs according to topology
--io-skip-eagain skip EAGAIN errors
--io-min-time <time>
all IO faster than min-time will visually appear longer
--io-merge-dist <time>
merge events that are merge-dist us apart
As shown above, the -f option does not work at all.
After this patch:
# perf timechart
File perf.data not owned by current user or root (use -f to override)
# perf timechart -f
Written 0.0 seconds of trace to output.svg.
# cat output.svg
<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg SYSTEM "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="1000" height="10110" version="1.1" xmlns="http://www.w3.org/2000/svg">
<defs>
<style type="text/css">
<![CDATA[
rect { stroke-width: 1; }
...
...
As shown above, the -f option really works now.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-9-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Yunlong Song [Thu, 2 Apr 2015 13:47:16 +0000 (21:47 +0800)]
perf script: Support using -f to override perf.data file ownership
Enable perf script to use perf.data when it is not owned by current user
or root. Change the short option name of --fields to -F to avoid confusion
with --force.
Example:
# perf record ls
# chown Yunlong.Song:Yunlong.Song perf.data
# ls -al perf.data
-rw------- 1 Yunlong.Song Yunlong.Song 28360 Apr 2 14:53 perf.data
# id
uid=0(root) gid=0(root) groups=0(root),64(pkcs11)
Before this patch:
# perf script
File perf.data not owned by current user or root (use -f to override)
# perf script -f
Error: switch `f' requires a value
As shown above, the -f option does not work at all. And -f is already
taken up by --fields, which makes --force confused, so change the short
option name of --fields to -F like what other perf commands do (e.g.
perf report -F) and use -f as the short option name of --force.
After this patch:
# perf script
File perf.data not owned by current user or root (use -f to override)
# perf script -f
:41298 41298 2590086.564226: 1 cycles: ffffffff8103efc6
native_write_msr_safe ([kernel.kallsyms])
:41298 41298 2590086.564244: 1 cycles: ffffffff8103efc6
native_write_msr_safe ([kernel.kallsyms])
:41298 41298 2590086.564249: 7 cycles: ffffffff8103efc6
native_write_msr_safe ([kernel.kallsyms])
:41298 41298 2590086.564255: 176 cycles: ffffffff8103efc6
native_write_msr_safe ([kernel.kallsyms])
ls 41298 2590086.567346: 4059 cycles: ffffffff8105a592
raise_softirq ([kernel.kallsyms])
ls 41298 2590086.567353: 3717 cycles: ffffffff8105a592
raise_softirq ([kernel.kallsyms])
ls 41298 2590086.567358: 63058 cycles: ffffffff8105a592
raise_softirq ([kernel.kallsyms])
ls 41298 2590086.567448: 1706255 cycles: 406ae0
[unknown] (/usr/bin/ls)
As shown above, the -f option really works now.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-8-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Yunlong Song [Thu, 2 Apr 2015 13:47:15 +0000 (21:47 +0800)]
perf mem: Support using -f to override perf.data file ownership
Enable perf mem to use perf.data when it is not owned by current user or
root.
Example:
# perf mem -t load record ls
# chown Yunlong.Song:Yunlong.Song perf.data
# ls -al perf.data
-rw------- 1 Yunlong.Song Yunlong.Song 16392 Apr 2 14:34 perf.data
# id
uid=0(root) gid=0(root) groups=0(root),64(pkcs11)
Before this patch:
# perf mem -D report
File perf.data not owned by current user or root (use -f to override)
# perf mem -D -f report
Error: unknown switch `f'
usage: perf mem [<options>] {record|report}
-t, --type <type> memory operations(load,store) Default load,store
-D, --dump-raw-samples
dump raw samples in ASCII
-U, --hide-unresolved
Only display entries resolved to a symbol
-i, --input <file> input file name
-C, --cpu <cpu> list of cpus to profile
-x, --field-separator <separator>
separator for columns, no spaces will be added
between columns '.' is reserved.
As shown above, the -f option does not work at all.
After this patch:
# perf mem -D report
File perf.data not owned by current user or root (use -f to override)
# perf mem -D -f report
# PID, TID, IP, ADDR, LOCAL WEIGHT, DSRC, SYMBOL
39095 39095 0xffffffff81127e40 0x016ffff887f45148338 8 0x68100142
/proc/kcore:perf_event_aux
39095 39095 0xffffffff8100a3fe 0xffff89007f8cb7d0 6 0x68100142
/proc/kcore:native_sched_clock
39095 39095 0xffffffff81309139 0xffff88bf44c9ded8 6 0x68100142
/proc/kcore:acpi_map_lookup
39095 39095 0xffffffff810f8c4c 0xffff89007f8ccd88 6 0x68100142
/proc/kcore:rcu_nmi_exit
39095 39095 0xffffffff81136346 0xffff88fea995dd50 6 0x68100142
/proc/kcore:unlock_page
39095 39095 0xffffffff812a64a2 0xffff88fea995dcc8 6 0x68100142
/proc/kcore:half_md4_transform
39095 39095 0x7f0cf877c7e9 0x25dfb94 6 0x68100142
/lib64/libc-2.19.so:__readdir64
39095 39095 0x7f0cf87575a3 0x7f0cf9163731 6 0x68100142
/lib64/libc-2.19.so:__strcoll_l
39095 39095 0xffffffff8116910e 0xffffea01c1bfbd50 23 0x68100242
/proc/kcore:page_remove_rmap
As shown above, the -f option really works now.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-7-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Yunlong Song [Thu, 2 Apr 2015 13:47:14 +0000 (21:47 +0800)]
perf lock: Support using -f to override perf.data file ownership
Enable perf lock to use perf.data when it is not owned by current user
or root.
Example:
# perf lock record ls
# chown Yunlong.Song:Yunlong.Song perf.data
# ls -al perf.data
-rw------- 1 Yunlong.Song Yunlong.Song 4880686 Apr 2 14:14 perf.data
# id
uid=0(root) gid=0(root) groups=0(root),64(pkcs11)
Before this patch:
# perf lock report
File perf.data not owned by current user or root (use -f to override)
Initializing perf session failed
# perf lock report -f
Error: unknown switch `f'
As shown above, the -f option does not work at all.
After this patch:
# perf lock report
File perf.data not owned by current user or root (use -f to override)
Initializing perf session failed
# perf lock report -f
Name acquired contended avg wait (ns) total wait (ns) ...
Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-6-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Yunlong Song [Thu, 2 Apr 2015 13:47:13 +0000 (21:47 +0800)]
perf kvm: Support using -f to override perf.data.guest file ownership
Enable perf kvm to use perf.data.guest when it is not owned by current
user or root.
Example:
# perf kvm stat record ls
# chown Yunlong.Song:Yunlong.Song perf.data.guest
# ls -al perf.data.guest
-rw------- 1 Yunlong.Song Yunlong.Song 4128937 Apr 2 11:05 perf.data.guest
# id
uid=0(root) gid=0(root) groups=0(root),64(pkcs11)
Before this patch:
# perf kvm stat report
File perf.data.guest not owned by current user or root (use -f to override)
Initializing perf session failed
# perf kvm stat report -f
Error: unknown switch `f'
usage: perf kvm stat report [<options>]
--event <report event>
event for reporting: vmexit, mmio (x86 only),
ioport (x86 only)
--vcpu <n> vcpu id to report
-k, --key <sort-key> key for sorting: sample(sort by samples
number) time (sort by avg time)
-p, --pid <pid> analyze events only for given process id(s)
As shown above, the -f option does not work at all.
After this patch:
# perf kvm stat report
File perf.data.guest not owned by current user or root (use -f to override)
Initializing perf session failed
# perf kvm stat report -f
Analyze events for all VMs, all VCPUs:
VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
Total Samples:0, Total events handled time:0.00us.
As shown above, the -f option really works now. Since we have not
launched any KVM related process, the result shows 0 sample here.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-5-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Yunlong Song [Thu, 2 Apr 2015 13:47:12 +0000 (21:47 +0800)]
perf kmem: Support using -f to override perf.data file ownership
Enable perf kmem to use perf.data when it is not owned by current user
or root.
Example:
# perf kmem record ls
# chown Yunlong.Song:Yunlong.Song perf.data
# ls -al perf.data
-rw------- 1 Yunlong.Song Yunlong.Song 5315665 Apr 2 10:54 perf.data
# id
uid=0(root) gid=0(root) groups=0(root),64(pkcs11)
Before this patch:
# perf kmem stat
File perf.data not owned by current user or root (use -f to override)
# perf kmem stat -f
Error: unknown switch `f'
usage: perf kmem [<options>] {record|stat}
-i, --input <file> input file name
-v, --verbose be more verbose (show symbol address, etc)
--caller show per-callsite statistics
--alloc show per-allocation statistics
-s, --sort <key[,key2...]>
sort by keys: ptr, call_site, bytes, hit,
pingpong, frag
-l, --line <num> show n lines
--raw-ip show raw ip instead of symbol
As shown above, the -f option does not work at all.
After this patch:
# perf kmem stat
File perf.data not owned by current user or root (use -f to override)
# perf kmem stat -f
SUMMARY
=======
Total bytes requested: 437599
Total bytes allocated: 615472
Total bytes wasted on internal fragmentation: 177873
Internal fragmentation: 28.900259%
Cross CPU allocations: 6/1192
As shown above, the -f option really works now.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-4-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Yunlong Song [Thu, 2 Apr 2015 13:47:11 +0000 (21:47 +0800)]
perf inject: Support using -f to override perf.data file ownership
Enable perf inject to use perf.data when it is not owned by current user
or root.
Example:
# perf record ls
# chown Yunlong.Song:Yunlong.Song perf.data
# ls -al perf.data
-rw------- 1 Yunlong.Song Yunlong.Song 28260 Apr 2 10:37 perf.data
# id
uid=0(root) gid=0(root) groups=0(root),64(pkcs11)
Before this patch:
# perf inject -v -b -i perf.data -o perf.data.new
File perf.data not owned by current user or root (use -f to override)
# perf inject -v -b -i perf.data -o perf.data.new -f
Error: unknown switch `f'
usage: perf inject [<options>]
-b, --build-ids Inject build-ids into the output stream
-i, --input <file> input file name
-o, --output <file> output file name
-s, --sched-stat Merge sched-stat and sched-switch for getting
events where and how long tasks slept
-v, --verbose be more verbose (show build ids, etc)
--kallsyms <file>
kallsyms pathname
As shown above, the -f option does not work at all.
After this patch:
# perf inject -v -b -i perf.data -o perf.data.new
File perf.data not owned by current user or root (use -f to override)
# perf inject -v -b -i perf.data -o perf.data.new -f
build id event received for [kernel.kallsyms]: f6dcb66d8b98f1c0d9eb87bf043444b69f91d30c
symsrc__init: cannot get elf header.
Looking at the vmlinux_path (7 entries long)
Using /proc/kcore for kernel object code
Using /proc/kallsyms for symbols
As shown above, the -f option really works now.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-3-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Yunlong Song [Thu, 2 Apr 2015 13:47:10 +0000 (21:47 +0800)]
perf evlist: Support using -f to override perf.data file ownership
Enable perf evlist to use perf.data when it is not owned by current user
or root.
Example:
# perf record ls
# chown Yunlong.Song:Yunlong.Song perf.data
# ls -al perf.data
-rw------- 1 Yunlong.Song Yunlong.Song 28260 Apr 2 10:18 perf.data
# id
uid=0(root) gid=0(root) groups=0(root),64(pkcs11)
Before this patch:
# perf evlist
File perf.data not owned by current user or root (use -f to override)
# perf evlist -f
Error: unknown switch `f'
usage: perf evlist [<options>]
-i, --input <file> Input file name
-F, --freq Show the sample frequency
-v, --verbose Show all event attr details
-g, --group Show event group information
As shown above, the -f option does not work at all.
After this patch:
# perf evlist
File perf.data not owned by current user or root (use -f to override)
# perf evlist -f
cycles
As shown above, the -f option really works now.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-2-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf probe: Fix to track down unnamed union/structure members
Fix 'perf probe' to track down unnamed union/structure members.
perf probe did not track down the tree of unnamed union/structure
members, since it just failed to find given "name" in a parent
structure/union. To solve this issue, I've introduced 2 changes.
- Fix die_find_member() to track down the type-DIE if it is
unnamed, and if it contains the specified member, returns the
unnamed member.
(note that we don't return found member, since unnamed member
has the offset in the parent structure)
- Fix convert_variable_fields() to track down the unnamed union/
structure (one-by-one).
With this patch, perf probe can access unnamed fields:
-----
#./perf probe -nfx ./perf lock__delete ops 'locked_ops=ops->locked.ops'
Added new event:
probe_perf:lock__delete (on lock__delete in /home/mhiramat/ksrc/linux-3/tools/perf/perf with ops locked_ops=ops->locked.ops)
You can now use it in all perf tools, such as:
perf record -e probe_perf:lock__delete -aR sleep 1
-----
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Link: https://lkml.org/lkml/2015/3/5/431 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20150402073312.14482.37942.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
bpf: Fix the build on BPF_SYSCALL=y && !CONFIG_TRACING kernels, make it more configurable
So bpf_tracing.o depends on CONFIG_BPF_SYSCALL - but that's not its only
dependency, it also depends on the tracing infrastructure and on kprobes,
without which it will fail to build with:
In file included from kernel/trace/bpf_trace.c:14:0:
kernel/trace/trace.h: In function ‘trace_test_and_set_recursion’:
kernel/trace/trace.h:491:28: error: ‘struct task_struct’ has no member named ‘trace_recursion’
unsigned int val = current->trace_recursion;
[...]
It took quite some time to trigger this build failure, because right now
BPF_SYSCALL is very obscure, depends on CONFIG_EXPERT. So also make BPF_SYSCALL
more configurable, not just under CONFIG_EXPERT.
If BPF_SYSCALL, tracing and kprobes are enabled then enable the bpf_tracing
gateway as well.
We might want to make this an interactive option later on, although
I'd not complicate it unnecessarily: enabling BPF_SYSCALL is enough of
an indicator that the user wants BPF support.
Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
One BPF program attaches to kmem_cache_alloc_node() and
remembers all allocated objects in the map.
Another program attaches to kmem_cache_free() and deletes
corresponding object from the map.
User space walks the map every second and prints any objects
which are older than 1 second.
Usage:
$ sudo tracex4
Then start few long living processes. The 'tracex4' will print
something like this:
obj 0xffff880465928000 is 13sec old was allocated at ip ffffffff8105dc32
obj 0xffff88043181c280 is 13sec old was allocated at ip ffffffff8105dc32
obj 0xffff880465848000 is 8sec old was allocated at ip ffffffff8105dc32
obj 0xffff8804338bc280 is 15sec old was allocated at ip ffffffff8105dc32
$ addr2line -fispe vmlinux ffffffff8105dc32
do_fork at fork.c:1665
As soon as processes exit the memory is reclaimed and 'tracex4'
prints nothing.
Similar experiment can be done with the __kmalloc()/kfree() pair.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1427312966-8434-10-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
BPF C program attaches to
blk_mq_start_request()/blk_update_request() kprobe events to
calculate IO latency.
For every completed block IO event it computes the time delta
in nsec and records in a histogram map:
map[log10(delta)*10]++
User space reads this histogram map every 2 seconds and prints
it as a 'heatmap' using gray shades of text terminal. Black
spaces have many events and white spaces have very few events.
Left most space is the smallest latency, right most space is
the largest latency in the range.
Usage:
$ sudo ./tracex3
and do 'sudo dd if=/dev/sda of=/dev/null' in other terminal.
Observe IO latencies and how different activity (like 'make
kernel') affects it.
Similar experiments can be done for network transmit latencies,
syscalls, etc.
'-t' flag prints the heatmap using normal ascii characters:
samples/bpf: Add counting example for kfree_skb() function calls and the write() syscall
this example has two probes in one C file that attach to
different kprove events and use two different maps.
1st probe is x64 specific equivalent of dropmon. It attaches to
kfree_skb, retrevies 'ip' address of kfree_skb() caller and
counts number of packet drops at that 'ip' address. User space
prints 'location - count' map every second.
2nd probe attaches to kprobe:sys_write and computes a histogram
of different write sizes
samples/bpf: Add simple non-portable kprobe filter example
tracex1_kern.c - C program compiled into BPF.
It attaches to kprobe:netif_receive_skb()
When skb->dev->name == "lo", it prints sample debug message into
trace_pipe via bpf_trace_printk() helper function.
tracex1_user.c - corresponding user space component that:
- loads BPF program via bpf() syscall
- opens kprobes:netif_receive_skb event via perf_event_open()
syscall
- attaches the program to event via ioctl(event_fd,
PERF_EVENT_IOC_SET_BPF, prog_fd);
- prints from trace_pipe
Note, this BPF program is non-portable. It must be recompiled
with current kernel headers. kprobe is not a stable ABI and
BPF+kprobe scripts may no longer be meaningful when kernel
internals change.
No matter in what way the kernel changes, neither the kprobe,
nor the BPF program can ever crash or corrupt the kernel,
assuming the kprobes, perf and BPF subsystem has no bugs.
The verifier will detect that the program is using
bpf_trace_printk() and the kernel will print 'this is a DEBUG
kernel' warning banner, which means that bpf_trace_printk()
should be used for debugging of the BPF program only.
tracing: Allow BPF programs to call bpf_trace_printk()
Debugging of BPF programs needs some form of printk from the
program, so let programs call limited trace_printk() with %d %u
%x %p modifiers only.
Similar to kernel modules, during program load verifier checks
whether program is calling bpf_trace_printk() and if so, kernel
allocates trace_printk buffers and emits big 'this is debug
only' banner.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1427312966-8434-6-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
tracing, perf: Implement BPF programs attached to kprobes
BPF programs, attached to kprobes, provide a safe way to execute
user-defined BPF byte-code programs without being able to crash or
hang the kernel in any way. The BPF engine makes sure that such
programs have a finite execution time and that they cannot break
out of their sandbox.
The user interface is to attach to a kprobe via the perf syscall:
'prog_fd' is a file descriptor associated with BPF program
previously loaded.
'event_id' is an ID of the kprobe created.
Closing 'event_fd':
close(event_fd);
... automatically detaches BPF program from it.
BPF programs can call in-kernel helper functions to:
- lookup/update/delete elements in maps
- probe_read - wraper of probe_kernel_read() used to access any
kernel data structures
BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is
architecture dependent) and return 0 to ignore the event and 1 to store
kprobe event into the ring buffer.
Note, kprobes are a fundamentally _not_ a stable kernel ABI,
so BPF programs attached to kprobes must be recompiled for
every kernel version and user must supply correct LINUX_VERSION_CODE
in attr.kern_version during bpf_prog_load() call.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
add TRACE_EVENT_FL_KPROBE flag to differentiate kprobe type of
tracepoints, since bpf programs can only be attached to kprobe
type of PERF_TYPE_TRACEPOINT perf events.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1427312966-8434-3-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Borkmann [Wed, 25 Mar 2015 19:49:18 +0000 (12:49 -0700)]
bpf: Make internal bpf API independent of CONFIG_BPF_SYSCALL #ifdefs
Socket filter code and other subsystems with upcoming eBPF
support should not need to deal with the fact that we have
CONFIG_BPF_SYSCALL defined or not.
Having the bpf syscall as a config option is a nice thing and
I'd expect it to stay that way for expert users (I presume one
day the default setting of it might change, though), but code
making use of it should not care if it's actually enabled or
not.
Instead, hide this via header files and let the rest deal with it.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1427312966-8434-2-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
By keeping pointers to machines, evlist and tool in ordered_events.
But that was more a transitional patch while moving stuff out from
perf_session.c to ordered_events.c and possibly not even needed by then,
as we could use the container_of() method and instead of having the
nr_unordered_samples stats in events_stats, we can have it in
ordered_samples.
Based-on-a-patch-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-4lk0t9js82g0tfc0x1onpkjt@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Even when it is not used to actually reorder events, some of its fields
are used, like session->ordered_events->tool, to shorten function
signatures where tool, for instance, was being passed, as the tool is
needed for the ordered_events code, we need it there and might as well
use it for other perf_session needs.
This fixes a problem where 'perf script' had some condition that made
session->ordered_events not to be initialized even with its
script->tool ordered_events related flags asking for it to be, which
looks like another bug and needs to be investigated further.
Always initializing session->ordered_events at least leaves the current
assumptions in place, so do it now.
Reported-by: David Ahern <dsahern@gmail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Tested-by: David Ahern <dsahern@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-b1xxk0rwkz2a0gip1uufmjqg@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
David Ahern [Mon, 30 Mar 2015 20:35:58 +0000 (14:35 -0600)]
perf tools: Fix ppid for synthesized fork events
363b785f38 added synthesized fork events and set a thread's parent id to
itself. Since we are already processing /proc/<pid>/status the ppid can
be determined properly. Make it so.
perf callchain: Fix kernel symbol resolution by remembering the cpumode
Commit 2e77784bb7d8 ("perf callchain: Move cpumode resolve code to
add_callchain_ip") promised "No change in behavior.".
As this commit breaks callchains on s390x (symbols not getting resolved,
observed when profiling the kernel), this statement is wrong. The cpumode
must be kept when iterating over all ips, otherwise the default
(PERF_RECORD_MISC_USER) will be used by error.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1427703060-59883-1-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Jiri Olsa [Sat, 28 Mar 2015 10:30:30 +0000 (11:30 +0100)]
perf build: Disable libbabeltrace check by default
Disabling libbabeltrace check by default and replacing the
NO_LIBBABELTRACE make variable with LIBBABELTRACE.
Users wanting the libbabeltrace feature need to build via:
$ make LIBBABELTRACE=1
The reason for this is that the libababeltrace interface we use (version
1.3) hasn't been packaged/released yet, thus the failing feature check
only slows down build and confuses other (non CTF) developers.
Requested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeremie Galarneau <jgalar@efficios.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20150328103030.GA8431@krava.redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Peter Zijlstra [Fri, 20 Feb 2015 13:05:38 +0000 (14:05 +0100)]
perf: Add per event clockid support
While thinking on the whole clock discussion it occurred to me we have
two distinct uses of time:
1) the tracking of event/ctx/cgroup enabled/running/stopped times
which includes the self-monitoring support in struct
perf_event_mmap_page.
2) the actual timestamps visible in the data records.
And we've been conflating them.
The first is all about tracking time deltas, nobody should really care
in what time base that happens, its all relative information, as long
as its internally consistent it works.
The second however is what people are worried about when having to
merge their data with external sources. And here we have the
discussion on MONOTONIC vs MONOTONIC_RAW etc..
Where MONOTONIC is good for correlating between machines (static
offset), MONOTNIC_RAW is required for correlating against a fixed rate
hardware clock.
This means configurability; now 1) makes that hard because it needs to
be internally consistent across groups of unrelated events; which is
why we had to have a global perf_clock().
However, for 2) it doesn't really matter, perf itself doesn't care
what it writes into the buffer.
The below patch makes the distinction between these two cases by
adding perf_event_clock() which is used for the second case. It
further makes this configurable on a per-event basis, but adds a few
sanity checks such that we cannot combine events with different clocks
in confusing ways.
And since we then have per-event configurability we might as well
retain the 'legacy' behaviour as a default.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Ingo Molnar [Fri, 27 Mar 2015 09:09:21 +0000 (10:09 +0100)]
Merge branch 'timers/core' into perf/timer, to apply dependent patch
An upcoming patch will depend on tai_ns() and NMI-safe ktime_get_raw_fast(),
so merge timers/core here in a separate topic branch until it's all cooked
and timers/core is merged upstream.
Peter Zijlstra [Thu, 19 Mar 2015 09:09:06 +0000 (10:09 +0100)]
time: Rename timekeeper::tkr to timekeeper::tkr_mono
In preparation of adding another tkr field, rename this one to
tkr_mono. Also rename tk_read_base::base_mono to tk_read_base::base,
since the structure is not specific to CLOCK_MONOTONIC and the mono
name got added to the tk_read_base instance.
Lots of trivial churn.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150319093400.344679419@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andi Kleen [Wed, 18 Feb 2015 02:18:06 +0000 (18:18 -0800)]
perf/x86/intel: Add INST_RETIRED.ALL workarounds
On Broadwell INST_RETIRED.ALL cannot be used with any period
that doesn't have the lowest 6 bits cleared. And the period
should not be smaller than 128.
BDM11: When using a period < 100; we may get incorrect PEBS/PMI
interrupts and/or an invalid counter state.
BDM55: When bit0-5 of the period are !0 we may get redundant PEBS
records on overflow.
Add a new callback to enforce this, and set it for Broadwell.
How does this handle the case when an app requests a specific
period with some of the bottom bits set?
Short answer:
Any useful instruction sampling period needs to be 4-6 orders
of magnitude larger than 128, as an PMI every 128 instructions
would instantly overwhelm the system and be throttled.
So the +-64 error from this is really small compared to the
period, much smaller than normal system jitter.
Long answer (by Peterz):
IFF we guarantee perf_event_attr::sample_period >= 128.
Suppose we start out with sample_period=192; then we'll set period_left
to 192, we'll end up with left = 128 (we truncate the lower bits). We
get an interrupt, find that period_left = 64 (>0 so we return 0 and
don't get an overflow handler), up that to 128. Then we trigger again,
at n=256. Then we find period_left = -64 (<=0 so we return 1 and do get
an overflow). We increment with sample_period so we get left = 128. We
fire again, at n=384, period_left = 0 (<=0 so we return 1 and get an
overflow). And on and on.
So while the individual interrupts are 'wrong' we get then with
interval=256,128 in exactly the right ratio to average out at 192. And
this works for everything >=128.
So the num_samples*fixed_period thing is still entirely correct +- 127,
which is good enough I'd say, as you already have that error anyhow.
So no need to 'fix' the tools, al we need to do is refuse to create
INST_RETIRED:ALL events with sample_period < 128.
Andi Kleen [Wed, 18 Feb 2015 02:18:05 +0000 (18:18 -0800)]
perf/x86/intel: Add Broadwell core support
Add Broadwell support for Broadwell to perf.
The basic support is very similar to Haswell. We use the new cache
event list added for Haswell earlier. The only differences
are a few bits related to remote nodes. To avoid an extra,
mostly identical, table these are patched up in the initialization code.
The constraint list has one new event that needs to be handled over Haswell.
Andi Kleen [Wed, 18 Feb 2015 02:18:04 +0000 (18:18 -0800)]
perf/x86/intel: Add new cache events table for Haswell
Haswell offcore events are quite different from Sandy Bridge.
Add a new table to handle Haswell properly.
Note that the offcore bits listed in the SDM are not quite correct
(this is currently being fixed). An uptodate list of bits is
in the patch.
The basic setup is similar to Sandy Bridge. The prefetch columns
have been removed, as prefetch counting is not very reliable
on Haswell. One L1 event that is not in the event list anymore
has been also removed.
- data reads do not include code reads (comparable to earlier Sandy Bridge tables)
- data counts include speculative execution (except L1 write, dtlb, bpu)
- remote node access includes both remote memory, remote cache, remote mmio.
- prefetches are not included in the counts for consistency
(different from Sandy Bridge, which includes prefetches in the remote node)
Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Thompson [Thu, 26 Mar 2015 19:23:26 +0000 (12:23 -0700)]
timers, sched/clock: Avoid deadlock during read from NMI
Currently it is possible for an NMI (or FIQ on ARM) to come in
and read sched_clock() whilst update_sched_clock() has locked
the seqcount for writing. This results in the NMI handler
locking up when it calls raw_read_seqcount_begin().
This patch fixes the NMI safety issues by providing banked clock
data. This is a similar approach to the one used in Thomas
Gleixner's 4396e058c52e("timekeeping: Provide fast and NMI safe
access to CLOCK_MONOTONIC").
Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-6-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Thompson [Thu, 26 Mar 2015 19:23:25 +0000 (12:23 -0700)]
timers, sched/clock: Remove redundant notrace from update function
Currently update_sched_clock() is marked as notrace but this
function is not called by ftrace. This is trivially fixed by
removing the mark up.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-5-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Thompson [Thu, 26 Mar 2015 19:23:24 +0000 (12:23 -0700)]
timers, sched/clock: Remove suspend from clock_read_data()
Currently cd.read_data.suspended is read by the hotpath function
sched_clock(). This variable need not be accessed on the
hotpath. In fact, once it is removed, we can remove the
conditional branches from sched_clock() and install a dummy
read_sched_clock function to suspend the clock.
The new master copy of the function pointer
(actual_read_sched_clock) is introduced and is used for all
reads of the clock hardware except those within sched_clock
itself.
Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-4-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Thompson [Thu, 26 Mar 2015 19:23:23 +0000 (12:23 -0700)]
timers, sched/clock: Optimize cache line usage
Currently sched_clock(), a very hot code path, is not optimized
to minimise its cache profile. In particular:
1. cd is not ____cacheline_aligned,
2. struct clock_data does not distinguish between hotpath and
coldpath data, reducing locality of reference in the hotpath,
3. Some hotpath data is missing from struct clock_data and is marked
__read_mostly (which more or less guarantees it will not share a
cache line with cd).
This patch corrects these problems by extracting all hotpath
data into a separate structure and using ____cacheline_aligned
to ensure the hotpath uses a single (64 byte) cache line.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-3-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Thompson [Thu, 26 Mar 2015 19:23:22 +0000 (12:23 -0700)]
timers, sched/clock: Match scope of read and write seqcounts
Currently the scope of the raw_write_seqcount_begin/end() in
sched_clock_register() far exceeds the scope of the read section
in sched_clock(). This gives the impression of safety during
cursory review but achieves little.
Note that this is likely to be a latent issue at present because
sched_clock_register() is typically called before we enable
interrupts, however the issue does risk bugs being needlessly
introduced as the code evolves.
This patch fixes the problem by increasing the scope of the read
locking performed by sched_clock() to cover all data modified by
sched_clock_register.
We also improve clarity by moving writes to struct clock_data
that do not impact sched_clock() outside of the critical
section.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
[ Reworked it slightly to apply to tip/timers/core] Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-2-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Linus Torvalds [Thu, 26 Mar 2015 22:04:05 +0000 (15:04 -0700)]
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm refcounting fixes from Dave Airlie:
"Here is the complete set of i915 bug/warn/refcounting fixes"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/i915: Fixup legacy plane->crtc link for initial fb config
drm/i915: Fix atomic state when reusing the firmware fb
drm/i915: Keep ring->active_list and ring->requests_list consistent
drm/i915: Don't try to reference the fb in get_initial_plane_config()
drm: Fixup racy refcounting in plane_force_disable
Linus Torvalds [Thu, 26 Mar 2015 21:53:47 +0000 (14:53 -0700)]
Merge tag 'dm-4.0-fix-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fix from Mike Snitzer:
"Fix DM core device cleanup regression -- due to a latent race that was
exposed by the bdi changes that were introduced during the 4.0 merge"
* tag 'dm-4.0-fix-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm: fix add_disk() NULL pointer due to race with free_dev()
Linus Torvalds [Thu, 26 Mar 2015 21:43:42 +0000 (14:43 -0700)]
Merge tag 'linux-kselftest-4.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kselftest fix from Shuah Khan.
* tag 'linux-kselftest-4.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests: Fix build failures when invoked from kselftest target
Dave Airlie [Thu, 26 Mar 2015 21:39:45 +0000 (07:39 +1000)]
Merge tag 'drm-intel-fixes-2015-03-26' of git://anongit.freedesktop.org/drm-intel into drm-fixes
This should cover the final warnings in -rc5 with two more backports
from our development branch (drm-intel-next-queued). They're the ones
from Daniel and Damien, with references to the reports.
This is on top of drm-fixes because of the dependency on the two earlier
fixes not yet in Linus' tree.
There's an additional regression fix from Chris.
* tag 'drm-intel-fixes-2015-03-26' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Fixup legacy plane->crtc link for initial fb config
drm/i915: Fix atomic state when reusing the firmware fb
drm/i915: Keep ring->active_list and ring->requests_list consistent
Linus Torvalds [Thu, 26 Mar 2015 21:11:17 +0000 (14:11 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Martin Schwidefsky:
"A couple of bug fixes for s390.
The ftrace comile fix is quite large for a -rc6 release, but it would
be nice to have it in 4.0"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/smp: reenable smt after resume
s390/mm: limit STACK_RND_MASK for compat tasks
s390/ftrace: fix compile error if CONFIG_KPROBES is disabled
s390/cpum_sf: add diagnostic sampling event only if it is authorized
Steven Rostedt [Tue, 24 Mar 2015 18:58:13 +0000 (14:58 -0400)]
tools lib traceevent: Zero should not be considered "not found" in eval_flag()
Guilherme Cox found that:
There is, however, a potential bug if there is an item with code zero
that is not the first one in the symbol list, since eval_flag(..)
returns 0 when it doesn't find anything.
If none of the enums are known to pevent, then eval_flag() will return
zero, and it will match it to the first item in the list, which would be
FOO_GO, which is not zero.
Luckily, in most cases, the first element would be zero, and the parsing
would match out of sheer luck.
Reported-by: Guilherme Cox <cox@computer.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20150324145813.0bfe95ba@gandalf.local.home Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf trace: Handle multiple threads better wrt syscalls being intermixed
Introduced a bug where it considered the number of bytes output directly
to the output file when formatting the syscall entry buffer that is
stored to be finally printed at syscall exit, ending up leaving garbage
at the start of syscalls that appeared while another syscall was being
processed, in another thread. Fix it.
Example of garbage in the output before this patch:
David Ahern [Tue, 24 Mar 2015 16:10:55 +0000 (12:10 -0400)]
perf tools: Set JOBS based on CPU or processor
Number of JOBS to use is set automatically to the number of processors found
in /proc/cpuinfo. SPARC uses 'CPU' lines rather than 'processor'. Update the
check in perf's Makefile to work for SPARC.
perf evlist: Return the first evsel with an invalid filter in apply_filters()
Use of a bad filter currently generates the message:
Error: failed to set filter with 22 (Invalid argument)
Add the event name to make it clear to which event the filter
failed to apply:
Error: Failed to set filter "foo" on event sched:sg_lb_stats: 22: Invalid argument
To test it use something like:
# perf record -e sched:sched_switch -e sched:*fork --filter parent_pid==1 -e sched:*wait* --filter bla usleep 1
Error: failed to set filter "bla" on event sched:sched_stat_iowait with 22 (Invalid argument)
#
Based-on-a-patch-by: David Ahern <dsahern@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-d7gq2fjvaecozp9o2i0siifu@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
David Ahern [Tue, 24 Mar 2015 20:14:09 +0000 (16:14 -0400)]
perf timechart: Fix SIBGUS error on sparc64
perf timechart -T on sparc64 is terminating due to SIGBUS. Backtrace:
Program received signal SIGBUS, Bus error.
0x0000000000173d7c in perf_evsel__intval (evsel=<value optimized out>, sample=0x7feffffda28, name=0x289b28 "prev_state")
at util/evsel.c:1918
1918 util/evsel.c: No such file or directory.
in util/evsel.c
Missing separate debuginfos, use: debuginfo-install audit-libs-2.3.7-1.0.1.el6.sparc64 bzip2-libs-1.0.5-7.el6_0.sparc64 elfutils-libelf-0.155-2.0.3.el6.sparc64 elfutils-libs-0.155-2.0.3.el6.sparc64 glibc-2.12-1.132.0.8.el6_5.sparc64 numactl-2.0.7-8.el6.sparc64 python-libs-2.6.6-52.0.2.el6.sparc64 slang-2.2.1-1.el6.sparc64 xz-libs-4.999.9-0.3.beta.20091007git.el6.sparc64 zlib-1.2.3-29.el6.sparc64
(gdb) bt
0 0x0000000000173d7c in perf_evsel__intval (evsel=<value optimized out>, sample=0x7feffffda28,
name=0x289b28 "prev_state") at util/evsel.c:1918
1 0x0000000000123b94 in process_sample_sched_switch (tchart=0x7feffffe040, evsel=0x4ca850, sample=0x7feffffda28,
backtrace=0xc39010 "") at builtin-timechart.c:627
2 0x0000000000122828 in process_sample_event (tool=0x7feffffe040, event=<value optimized out>, sample=0x7feffffda28,
evsel=0x4ca850, machine=0x4c9c88) at builtin-timechart.c:569
Another extended load on unaligned pointer. As before fix by copying to
a temporary variable using memcpy.
drm/i915: Fix modeset state confusion in the load detect code
But this time around it was the initial fb code that forgot to update
the plane->crtc pointer. Otherwise it's the exact same bug, with the
exact same restrains (any set_config call/ioctl that doesn't disable
the pipe papers over the bug for free, so fairly hard to hit in normal
testing). So if you want the full explanation just go read that one
over there - it's rather long ...
Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Josh Boyer <jwboyer@fedoraproject.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Reported-and-tested-by: Josh Boyer <jwboyer@fedoraproject.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[Jani: backported to drm-intel-fixes for v4.0-rc]
Reference: http://mid.gmane.org/CA+5PVA7ChbtJrknqws1qvZcbrg1CW2pQAFkSMURWWgyASRyGXg@mail.gmail.com Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Chris Wilson [Wed, 18 Mar 2015 18:19:22 +0000 (18:19 +0000)]
drm/i915: Keep ring->active_list and ring->requests_list consistent
If we retire requests last, we may use a later seqno and so clear
the requests lists without clearing the active list, leading to
confusion. Hence we should retire requests first for consistency with
the early return. The order used to be important as the lifecycle for
the object on the active list was determined by request->seqno. However,
the requests themselves are now reference counted removing the
constraint from the order of retirement.
drm/i915: Convert 'i915_seqno_passed' calls into 'i915_gem_request_completed
'
and a
WARNING: CPU: 0 PID: 1383 at drivers/gpu/drm/i915/i915_gem_evict.c:279 i915_gem_evict_vm+0x10c/0x140()
WARN_ON(!list_empty(&vm->active_list))
Identified by updating WATCH_LISTS:
[drm:i915_verify_lists] *ERROR* blitter ring: active list not empty, but no requests
WARNING: CPU: 0 PID: 681 at drivers/gpu/drm/i915/i915_gem.c:2751 i915_gem_retire_requests_ring+0x149/0x230()
WARN_ON(i915_verify_lists(ring->dev))
Note that this is only a problem in evict_vm where the following happens
after a retire_request has cleaned out all requests, but not all active
bo:
- intel_ring_idle called from i915_gpu_idle notices that no requests are
outstanding and immediately returns.
- i915_gem_retire_requests_ring called from i915_gem_retire_requests also
immediately returns when there's no request, still leaving the bo on the
active list.
- evict_vm hits the WARN_ON(!list_empty(&vm->active_list)) after evicting
all active objects that there's still stuff left that shouldn't be
there.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: John Harrison <John.C.Harrison@Intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Linus Torvalds [Wed, 25 Mar 2015 23:21:17 +0000 (16:21 -0700)]
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
"15 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm: numa: mark huge PTEs young when clearing NUMA hinting faults
mm: numa: slow PTE scan rate if migration failures occur
mm: numa: preserve PTE write permissions across a NUMA hinting fault
mm: numa: group related processes based on VMA flags instead of page table flags
hfsplus: fix B-tree corruption after insertion at position 0
MAINTAINERS: add Jan as DMI/SMBIOS support maintainer
fs/affs/file.c: unlock/release page on error
mm/page_alloc.c: call kernel_map_pages in unset_migrateype_isolate
mm/slub: fix lockups on PREEMPT && !SMP kernels
mm/memory hotplug: postpone the reset of obsolete pgdat
MAINTAINERS: correct rtc armada38x pattern entry
mm/pagewalk.c: prevent positive return value of walk_page_test() from being passed to callers
mm: fix anon_vma->degree underflow in anon_vma endless growing prevention
drivers/rtc/rtc-mrst: fix suspend/resume
aoe: update aoe maintainer information
Mel Gorman [Wed, 25 Mar 2015 22:55:45 +0000 (15:55 -0700)]
mm: numa: mark huge PTEs young when clearing NUMA hinting faults
Base PTEs are marked young when the NUMA hinting information is cleared
but the same does not happen for huge pages which this patch addresses.
Note that migrated pages are not marked young as the base page migration
code does not assume that migrated pages have been referenced. This
could be addressed but beyond the scope of this series which is aimed at
Dave Chinners shrink workload that is unlikely to be affected by this
issue.
Mel Gorman [Wed, 25 Mar 2015 22:55:42 +0000 (15:55 -0700)]
mm: numa: slow PTE scan rate if migration failures occur
Dave Chinner reported the following on https://lkml.org/lkml/2015/3/1/226
Across the board the 4.0-rc1 numbers are much slower, and the degradation
is far worse when using the large memory footprint configs. Perf points
straight at the cause - this is from 4.0-rc1 on the "-o bhash=101073" config:
This is showing excessive migration activity even though excessive
migrations are meant to get throttled. Normally, the scan rate is tuned
on a per-task basis depending on the locality of faults. However, if
migrations fail for any reason then the PTE scanner may scan faster if
the faults continue to be remote. This means there is higher system CPU
overhead and fault trapping at exactly the time we know that migrations
cannot happen. This patch tracks when migration failures occur and
slows the PTE scanner.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reported-by: Dave Chinner <david@fromorbit.com> Tested-by: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Wed, 25 Mar 2015 22:55:40 +0000 (15:55 -0700)]
mm: numa: preserve PTE write permissions across a NUMA hinting fault
Protecting a PTE to trap a NUMA hinting fault clears the writable bit
and further faults are needed after trapping a NUMA hinting fault to set
the writable bit again. This patch preserves the writable bit when
trapping NUMA hinting faults. The impact is obvious from the number of
minor faults trapped during the basis balancing benchmark and the system
CPU usage;
autonumabench
4.0.0-rc4 4.0.0-rc4
baseline preserve
Time System-NUMA01 107.13 ( 0.00%) 103.13 ( 3.73%)
Time System-NUMA01_THEADLOCAL 131.87 ( 0.00%) 83.30 ( 36.83%)
Time System-NUMA02 8.95 ( 0.00%) 10.72 (-19.78%)
Time System-NUMA02_SMT 4.57 ( 0.00%) 3.99 ( 12.69%)
Time Elapsed-NUMA01 515.78 ( 0.00%) 517.26 ( -0.29%)
Time Elapsed-NUMA01_THEADLOCAL 384.10 ( 0.00%) 384.31 ( -0.05%)
Time Elapsed-NUMA02 48.86 ( 0.00%) 48.78 ( 0.16%)
Time Elapsed-NUMA02_SMT 47.98 ( 0.00%) 48.12 ( -0.29%)
4.0.0-rc4 4.0.0-rc4
baseline preserve
User 44383.95 43971.89
System 252.61 201.24
Elapsed 998.68 1000.94
The patch looks hacky but the alternatives looked worse. The tidest was
to rewalk the page tables after a hinting fault but it was more complex
than this approach and the performance was worse. It's not generally
safe to just mark the page writable during the fault if it's a write
fault as it may have been read-only for COW so that approach was
discarded.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reported-by: Dave Chinner <david@fromorbit.com> Tested-by: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Wed, 25 Mar 2015 22:55:37 +0000 (15:55 -0700)]
mm: numa: group related processes based on VMA flags instead of page table flags
These are three follow-on patches based on the xfsrepair workload Dave
Chinner reported was problematic in 4.0-rc1 due to changes in page table
management -- https://lkml.org/lkml/2015/3/1/226.
Much of the problem was reduced by commit 53da3bc2ba9e ("mm: fix up numa
read-only thread grouping logic") and commit ba68bc0115eb ("mm: thp:
Return the correct value for change_huge_pmd"). It was known that the
performance in 3.19 was still better even if is far less safe. This
series aims to restore the performance without compromising on safety.
For the test of this mail, I'm comparing 3.19 against 4.0-rc4 and the
three patches applied on top
Overall the system CPU usage is comparable and the test is naturally a
bit variable. The slowing of the scanner hurts numa01 but on this
machine it is an adverse workload and patches that dramatically help it
often hurt absolutely everything else.
Due to patch 2, the fault activity is interesting
3.19.0 4.0.0-rc4 4.0.0-rc4 4.0.0-rc4 4.0.0-rc4
vanilla vanillavmwrite-v5r8preserve-v5r8slowscan-v5r8
Minor Faults 20978112656646259724919812301636841
Major Faults 362 450 365 364 365
Note the impact preserving the write bit across protection updates and
fault reduces faults.
Here the impact of slowing the PTE scanner on migratrion failures is
obvious as "NUMA base PTE updates" and "NUMA huge PMD updates" are
massively reduced even though the headline performance is very similar.
As xfsrepair was the reported workload here is the impact of the series
on it.
The really relevant lines as syst-xfsrepair which is the system CPU
usage when running xfsrepair. Note that on my machine the overhead was
45% higher on 4.0-rc4 which may be part of what Dave is seeing. Once we
preserve the write bit across faults, it's only 2.51% higher on average.
With the full series applied, system CPU usage is 24.6% lower on
average.
Again, the impact of preserving the write bit on minor faults is obvious
and the impact of slowing scanning after migration failures is obvious
on the PTE updates. Note also that the number of pages migrated is much
reduced even though the headline performance is comparable.
3.19.0 4.0.0-rc4 4.0.0-rc4 4.0.0-rc4 4.0.0-rc4
vanilla vanillavmwrite-v5r8preserve-v5r8slowscan-v5r8
Mean sdb-avgqusz 13.47 2.54 2.55 2.47 2.49
Mean sdb-avgrqsz 202.32 140.22 139.50 139.02 138.12
Mean sdb-await 25.92 5.09 5.33 5.02 5.22
Mean sdb-r_await 4.71 0.19 0.83 0.51 0.11
Mean sdb-w_await 104.13 5.21 5.38 5.05 5.32
Mean sdb-svctm 0.59 0.13 0.14 0.13 0.14
Mean sdb-rrqm 0.16 0.00 0.00 0.00 0.00
Mean sdb-wrqm 3.59 1799.43 1826.84 1812.21 1785.67
Max sdb-avgqusz 111.06 12.13 14.05 11.66 15.60
Max sdb-avgrqsz 255.60 190.34 190.01 187.33 191.78
Max sdb-await 168.24 39.28 49.22 44.64 65.62
Max sdb-r_await 660.00 52.00 280.00 76.00 12.00
Max sdb-w_await 7804.00 39.28 49.22 44.64 65.62
Max sdb-svctm 4.00 2.82 2.86 1.98 2.84
Max sdb-rrqm 8.30 0.00 0.00 0.00 0.00
Max sdb-wrqm 34.20 5372.80 5278.60 5386.60 5546.15
FWIW, I also checked SPECjbb in different configurations but it's
similar observations -- minor faults lower, PTE update activity lower
and performance is roughly comparable against 3.19.
This patch (of 3):
Threads that share writable data within pages are grouped together as
related tasks. This decision is based on whether the PTE is marked
dirty which is subject to timing races between the PTE scanner update
and when the application writes the page. If the page is file-backed,
then background flushes and sync also affect placement. This is
unpredictable behaviour which is impossible to reason about so this
patch makes grouping decisions based on the VMA flags.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reported-by: Dave Chinner <david@fromorbit.com> Tested-by: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergei Antonov [Wed, 25 Mar 2015 22:55:34 +0000 (15:55 -0700)]
hfsplus: fix B-tree corruption after insertion at position 0
Fix B-tree corruption when a new record is inserted at position 0 in the
node in hfs_brec_insert(). In this case a hfs_brec_update_parent() is
called to update the parent index node (if exists) and it is passed
hfs_find_data with a search_key containing a newly inserted key instead
of the key to be updated. This results in an inconsistent index node.
The bug reproduces on my machine after an extents overflow record for
the catalog file (CNID=4) is inserted into the extents overflow B-tree.
Because of a low (reserved) value of CNID=4, it has to become the first
record in the first leaf node.
A change in hfs_brec_insert() makes hfs_brec_update_parent() work
correctly by preventing it from getting fd->record=-1 value from
__hfs_brec_find().
Along the way, I removed duplicate code with unification of the if
condition. The resulting code is equivalent to the original code
because node is never 0.
Also hfs_brec_update_parent() will now return an error after getting a
negative fd->record value. However, the return value of
hfs_brec_update_parent() is not checked anywhere in the file and I'm
leaving it unchanged by this patch. brec.c lacks error checking after
some other calls too, but this issue is of less importance than the one
being fixed by this patch.
Signed-off-by: Sergei Antonov <saproj@gmail.com> Cc: Joe Perches <joe@perches.com> Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com> Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net> Cc: Anton Altaparmakov <aia21@cam.ac.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Taesoo Kim [Wed, 25 Mar 2015 22:55:29 +0000 (15:55 -0700)]
fs/affs/file.c: unlock/release page on error
When affs_bread_ino() fails, correctly unlock the page and release the
page cache with proper error value. All write_end() should
unlock/release the page that was locked by write_beg().
Signed-off-by: Taesoo Kim <tsgatesv@gmail.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Laura Abbott [Wed, 25 Mar 2015 22:55:26 +0000 (15:55 -0700)]
mm/page_alloc.c: call kernel_map_pages in unset_migrateype_isolate
Commit 3c605096d315 ("mm/page_alloc: restrict max order of merging on
isolated pageblock") changed the logic of unset_migratetype_isolate to
check the buddy allocator and explicitly call __free_pages to merge.
The page that is being freed in this path never had prep_new_page called
so set_page_refcounted is called explicitly but there is no call to
kernel_map_pages. With the default kernel_map_pages this is mostly
harmless but if kernel_map_pages does any manipulation of the page
tables (unmapping or setting pages to read only) this may trigger a
fault:
Mark Rutland [Wed, 25 Mar 2015 22:55:23 +0000 (15:55 -0700)]
mm/slub: fix lockups on PREEMPT && !SMP kernels
Commit 9aabf810a67c ("mm/slub: optimize alloc/free fastpath by removing
preemption on/off") introduced an occasional hang for kernels built with
CONFIG_PREEMPT && !CONFIG_SMP.
The problem is the following loop the patch introduced to
slab_alloc_node and slab_free:
do {
tid = this_cpu_read(s->cpu_slab->tid);
c = raw_cpu_ptr(s->cpu_slab);
} while (IS_ENABLED(CONFIG_PREEMPT) && unlikely(tid != c->tid));
GCC 4.9 has been observed to hoist the load of c and c->tid above the
loop for !SMP kernels (as in this case raw_cpu_ptr(x) is compile-time
constant and does not force a reload). On arm64 the generated assembly
looks like:
If the thread is preempted between the load of c->tid (into x1) and tid
(into x4), and an allocation or free occurs in another thread (bumping
the cpu_slab's tid), the thread will be stuck in the loop until
s->cpu_slab->tid wraps, which may be forever in the absence of
allocations/frees on the same CPU.
This patch changes the loop condition to access c->tid with READ_ONCE.
This ensures that the value is reloaded even when the compiler would
otherwise assume it could cache the value, and also ensures that the
load will not be torn.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Steve Capper <steve.capper@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cause is the "memset(pgdat, 0, sizeof(*pgdat))" at the end of
try_offline_node, which will reset all the content of pgdat to 0, as the
pgdat is accessed lock-free, so that the users still using the pgdat
will panic, such as the vmstat_update routine.
process A: offline node XX:
vmstat_updat()
refresh_cpu_vm_stats()
for_each_populated_zone()
find online node XX
cond_resched()
offline cpu and memory, then try_offline_node()
node_set_offline(nid), and memset(pgdat, 0, sizeof(*pgdat))
zone = next_zone(zone)
pg_data_t *pgdat = zone->zone_pgdat; // here pgdat is NULL now
next_online_pgdat(pgdat)
next_online_node(pgdat->node_id); // NULL pointer access
So the solution here is postponing the reset of obsolete pgdat from
try_offline_node() to hotadd_new_pgdat(), and just resetting
pgdat->nr_zones and pgdat->classzone_idx to be 0 rather than the memset
0 to avoid breaking pointer information in pgdat.
Naoya Horiguchi [Wed, 25 Mar 2015 22:55:14 +0000 (15:55 -0700)]
mm/pagewalk.c: prevent positive return value of walk_page_test() from being passed to callers
walk_page_test() is purely pagewalk's internal stuff, and its positive
return values are not intended to be passed to the callers of pagewalk.
However, in the current code if the last vma in the do-while loop in
walk_page_range() happens to return a positive value, it leaks outside
walk_page_range(). So the user visible effect is invalid/unexpected
return value (according to the reporter, mbind() causes it.)
This patch fixes it simply by reinitializing the return value after
checked.
Another exposed interface, walk_page_vma(), already returns 0 for such
cases so no problem.
Leon Yu [Wed, 25 Mar 2015 22:55:11 +0000 (15:55 -0700)]
mm: fix anon_vma->degree underflow in anon_vma endless growing prevention
I have constantly stumbled upon "kernel BUG at mm/rmap.c:399!" after
upgrading to 3.19 and had no luck with 4.0-rc1 neither.
So, after looking into new logic introduced by commit 7a3ef208e662 ("mm:
prevent endless growth of anon_vma hierarchy"), I found chances are that
unlink_anon_vmas() is called without incrementing dst->anon_vma->degree
in anon_vma_clone() due to allocation failure. If dst->anon_vma is not
NULL in error path, its degree will be incorrectly decremented in
unlink_anon_vmas() and eventually underflow when exiting as a result of
another call to unlink_anon_vmas(). That's how "kernel BUG at
mm/rmap.c:399!" is triggered for me.
This patch fixes the underflow by dropping dst->anon_vma when allocation
fails. It's safe to do so regardless of original value of dst->anon_vma
because dst->anon_vma doesn't have valid meaning if anon_vma_clone()
fails. Besides, callers don't care dst->anon_vma in such case neither.
Also suggested by Michal Hocko, we can clean up vma_adjust() a bit as
anon_vma_clone() now does the work.
[akpm@linux-foundation.org: tweak comment] Fixes: 7a3ef208e662 ("mm: prevent endless growth of anon_vma hierarchy") Signed-off-by: Leon Yu <chianglungyu@gmail.com> Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Moorestown RTC driver implements suspend and resume callbacks and
assigns them to the suspend and resume fields of the device_driver
struct. These callbacks are never actually called by anything though.
Modify the driver to properly use dev_pm_ops so that the suspend and
resume functions are actually executed upon suspend/resume.
Ed Cashin [Wed, 25 Mar 2015 22:55:06 +0000 (15:55 -0700)]
aoe: update aoe maintainer information
The coraid.com email address is defunct. The old aoe support area hosted
at coraid.com is no longer up. These changes update the email and website
to current ones.
Signed-off-by: Ed Cashin <ed.cashin@acm.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Wed, 25 Mar 2015 22:40:21 +0000 (15:40 -0700)]
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
"A small collection of fixes that has been gathered over the last few
weeks. This contains:
- A one-liner fix for NVMe, fixing a missing list_head init that
could makes us oops on hitting recovery at load time.
- Two small blk-mq fixes:
- Fixup a bad goto jump on error handling.
- Fix for oopsing if running out of reserved tags.
- A memory leak fix for NBD.
- Two small writeback fixes from Tejun, fixing a missing init to
INITIAL_JIFFIES, and a possible underflow introduced recently.
- A core merge fixup in sg gap detection, where rq->biotail was
indexed with the count of rq->bio"
* 'for-linus' of git://git.kernel.dk/linux-block:
writeback: fix possible underflow in write bandwidth calculation
NVMe: Initialize device list head before starting
Fix bug in blk_rq_merge_ok
blkmq: Fix NULL pointer deref when all reserved tags in
blk-mq: fix use of incorrect goto label in blk_mq_init_queue error path
nbd: fix possible memory leak
writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
Heiko Carstens [Sat, 21 Mar 2015 11:43:08 +0000 (12:43 +0100)]
s390/smp: reenable smt after resume
After a suspend/resume cycle we missed to enable smt again, which leads
to all sorts of bugs, since the kernel assumes smt is enabled, while the
hardware thinks it is not.
Reported-and-tested-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reported-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Linus Torvalds [Wed, 25 Mar 2015 00:27:18 +0000 (17:27 -0700)]
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull two arm64 fixes from Catalin Marinas:
- switch_mm() fix where init_mm.pgd ends up in the user TTBR0;
swapper_pg_dir is not suitable for user mappings
- this_cpu accessors fix for preemption safety
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: percpu: Make this_cpu accessors pre-empt safe
arm64: Use the reserved TTBR0 if context switching to the init_mm
Linus Torvalds [Wed, 25 Mar 2015 00:23:03 +0000 (17:23 -0700)]
Merge tag 'powerpc-4.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux
Pull powerpc fixes from Michael Ellerman:
- Fix the MCE code to use CONFIG_KVM_BOOK3S_64_HANDLER
- Little endian fixes for post mobility device tree update
- Add PVR for POWER8NVL processor
- Fixes for hypervisor doorbell handling
* tag 'powerpc-4.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
powerpc/book3s: Fix the MCE code to use CONFIG_KVM_BOOK3S_64_HANDLER
powerpc/pseries: Little endian fixes for post mobility device tree update
powerpc: Add PVR for POWER8NVL processor
powerpc/powernv: Fixes for hypervisor doorbell handling
Linus Torvalds [Wed, 25 Mar 2015 00:08:29 +0000 (17:08 -0700)]
Merge branch 'for-4.0-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
Pull libata fix from Tejun Heo:
"One patch to fix a regression from the recent switch to blk-mq tag
allocation which can cause oops on SAS-attached SATA drives"
* 'for-4.0-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
ata: Add a new flag to destinguish sas controller
Linus Torvalds [Wed, 25 Mar 2015 00:02:45 +0000 (17:02 -0700)]
Merge tag 'mfd-fixes-4.0' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd
Pull MFD fixes from Lee Jones:
- Use DMA'able addresses for DMA; rtsx_usb
- Use return value in the correct way; kempld-core
* tag 'mfd-fixes-4.0' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd:
mfd: kempld-core: Fix callback return value check
mfd: rtsx_usb: Prevent DMA from stack
drm/i915: Ensure plane->state->fb stays in sync with plane->fb
v2: Don't move update_state_fb(). It was moved around because I
originally put update_state_fb() in intel_alloc_plane_obj() before
finding a better place. (Matt)
Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Reported-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Signed-off-by: Damien Lespiau <damien.lespiau@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From drm-next:
(cherry picked from commit f55548b5af87ebfc586ca75748947f1c1b1a4a52) Signed-off-by: Dave Airlie <airlied@redhat.com>
Linus Torvalds [Tue, 24 Mar 2015 23:58:29 +0000 (16:58 -0700)]
Merge tag 'spi-v4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fixes from Mark Brown:
"A couple of driver specific fixes of the usual "important if you have
that device" kind together with a fix for a use after free bug that
was introduced into the trace code in some of the recent refactoring
of the message queue handling"
* tag 'spi-v4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: trigger trace event for message-done before mesg->complete
spi: dw-mid: clear BUSY flag fist and test other one
spi: qup: Fix cs-num DT property parsing
Linus Torvalds [Tue, 24 Mar 2015 23:51:42 +0000 (16:51 -0700)]
Merge tag 'regulator-fix-v4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator fixes from Mark Brown:
"Two fixes here, one typo fix in the documentation and one fix for a
system hang with one of the Palmas chips caused by the use of an
incorrect offset being provided for one of the registers"
* tag 'regulator-fix-v4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: Fix documentation for regmap in the config
regulator: palmas: Correct TPS659038 register definition for REGEN2
Linus Torvalds [Tue, 24 Mar 2015 23:42:54 +0000 (16:42 -0700)]
Merge tag 'regmap-fix-v4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
Pull regmap fix from Mark Brown:
"This patch fixes a bad interaction between the support that was added
for having regmaps without devices for early system controller
initialization and the trace support.
There's a very good analysis of the actual issue in the commit message
for the change"
* tag 'regmap-fix-v4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: introduce regmap_name to fix syscon regmap trace events
Steve Capper [Sun, 22 Mar 2015 14:51:51 +0000 (14:51 +0000)]
arm64: percpu: Make this_cpu accessors pre-empt safe
this_cpu operations were implemented for arm64 in: 5284e1b arm64: xchg: Implement cmpxchg_double f97fc81 arm64: percpu: Implement this_cpu operations
Unfortunately, it is possible for pre-emption to take place between
address generation and data access. This can lead to cases where data
is being manipulated by this_cpu for a different CPU than it was
called on. Which effectively breaks the spec.
This patch disables pre-emption for the this_cpu operations
guaranteeing that address generation and data manipulation take place
without a pre-emption in-between.
Fixes: 5284e1b4bc8a ("arm64: xchg: Implement cmpxchg_double") Fixes: f97fc810798c ("arm64: percpu: Implement this_cpu operations") Reported-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Steve Capper <steve.capper@linaro.org>
[catalin.marinas@arm.com: remove space after type cast] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
projects / karo-tx-linux.git / log