Ingo Molnar [Wed, 18 Feb 2015 18:14:54 +0000 (19:14 +0100)]
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
User visible changes:
- No need to explicitely enable evsels for workload started from perf, let it
be enabled via perf_event_attr.enable_on_exec, removing some events that take
place in the 'perf trace' before a workload is really started by it.
(Arnaldo Carvalho de Melo)
- Fix to handle optimized not-inlined functions in 'perf probe' (Masami Hiramatsu)
- Update 'perf probe' man page (Masami Hiramatsu)
- 'perf trace': Allow mixing with tracepoints and suppressing plain syscalls
(Arnaldo Carvalho de Melo)
Infrastructure changes:
- Introduce {trace_seq_do,event_format_}_fprintf functions to allow
a default tracepoint field list printer to be used in tools that allows
redirecting output to a file. (Arnaldo Carvalho de Melo)
- The man page for pthread_attr_set_affinity_np states that _GNU_SOURCE
must be defined before pthread.h, do it to fix the build in some
systems (Josh Boyer)
- Cleanups in 'perf buildid-cache' (Masami Hiramatsu)
- Fix dso cache test case (Namhyung Kim)
- Do Not rely on dso__data_read_offset() to open DSO (Namhyung Kim)
- Make perf aware of tracefs (Steven Rostedt).
- Fix build by defining STT_GNU_IFUNC for glibc 2.9 and older (Vinson Lee)
- AArch64 symbol resolution fixes (Victor Kamensky)
- Kconfig beachhead (Jiri Olsa)
- Simplify nr_pages validity (Kaixu Xia)
- Fixup header positioning in 'perf list' (Yunlong Song)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Kan Liang [Mon, 5 Jan 2015 18:23:05 +0000 (13:23 -0500)]
perf tools: Construct LBR call chain
LBR call stack only has user-space callchains. It is output in the
PERF_SAMPLE_BRANCH_STACK data format. For kernel callchains, it's
still in the form of PERF_SAMPLE_CALLCHAIN.
The perf tool has to handle both data sources to construct a
complete callstack.
For the "perf report -D" option, both lbr and fp information will be
displayed.
A new call chain recording option "lbr" is introduced into the perf
tool for LBR call stack. The user can use --call-graph lbr to get
the call stack information from hardware.
Here are some examples.
When profiling bc(1) on Fedora 19:
echo 'scale=2000; 4*a(1)' > cmd; perf record --call-graph lbr bc -l < cmd
If enabling LBR, perf report output looks like:
50.36% bc bc [.] bc_divide
|
--- bc_divide
execute
run_code
yyparse
main
__libc_start_main
_start
33.66% bc bc [.] _one_mult
|
--- _one_mult
bc_divide
execute
run_code
yyparse
main
__libc_start_main
_start
7.62% bc bc [.] _bc_do_add
|
--- _bc_do_add
|
|--99.89%-- 0x2000186a8
--0.11%-- [...]
6.83% bc bc [.] _bc_do_sub
|
--- _bc_do_sub
|
|--99.94%-- bc_add
| execute
| run_code
| yyparse
| main
| __libc_start_main
| _start
--0.06%-- [...]
0.46% bc libc-2.17.so [.] __memset_sse2
|
--- __memset_sse2
|
|--54.13%-- bc_new_num
| |
| |--51.00%-- bc_divide
| | execute
| | run_code
| | yyparse
| | main
| | __libc_start_main
| | _start
| |
| |--30.46%-- _bc_do_sub
| | bc_add
| | execute
| | run_code
| | yyparse
| | main
| | __libc_start_main
| | _start
| |
| --18.55%-- _bc_do_add
| bc_add
| execute
| run_code
| yyparse
| main
| __libc_start_main
| _start
|
--45.87%-- bc_divide
execute
run_code
yyparse
main
__libc_start_main
_start
If using FP, perf report output looks like:
echo 'scale=2000; 4*a(1)' > cmd; perf record --call-graph fp bc -l < cmd
50.49% bc bc [.] bc_divide
|
--- bc_divide
33.57% bc bc [.] _one_mult
|
--- _one_mult
7.61% bc bc [.] _bc_do_add
|
--- _bc_do_add
0x2000186a8
6.88% bc bc [.] _bc_do_sub
|
--- _bc_do_sub
0.42% bc libc-2.17.so [.] __memcpy_ssse3_back
|
--- __memcpy_ssse3_back
Kan Liang [Mon, 5 Jan 2015 18:23:04 +0000 (13:23 -0500)]
perf tools: Enable LBR call stack support
Currently, there are two call chain recording options, fp and dwarf.
Haswell has a new feature that utilizes the existing LBR facility to
record call chains. Kernel side LBR support code provides this as a
third option to record call chains. This patch enables the lbr call
stack support on the tooling side.
LBR call stack has some limitations:
- It reuses current LBR facility, so LBR call stack and branch record
can not be enabled at the same time.
- It is only available for user-space callchains.
However, it also offers some advantages:
- LBR call stack can work on user apps which don't have frame-pointers
or dwarf debug info compiled. It is a good alternative when nothing
else works.
Tested-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Cody P Schafer <cody@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Jacob Shin <jacob.w.shin@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masanari Iida <standby24x7@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Rodrigo Campos <rodrigo@sdfg.com.ar> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1420482185-29830-2-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:56:11 +0000 (21:56 -0500)]
perf/x86/intel: Discard zero length call entries in LBR call stack
"Zero length call" uses the attribute of the call instruction to push
the immediate instruction pointer on to the stack and then pops off
that address into a register. This is accomplished without any matching
return instruction. It confuses the hardware and make the recorded call
stack incorrect.
We can partially resolve this issue by: decode call instructions and
discard any zero length call entry in the LBR stack.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-16-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:56:10 +0000 (21:56 -0500)]
perf/x86/intel: Disable FREEZE_LBRS_ON_PMI when LBR operates in callstack mode
LBR callstack is designed for PEBS, It does not work well with
FREEZE_LBRS_ON_PMI for non PEBS event. If FREEZE_LBRS_ON_PMI is set for
non PEBS event, PMIs near call/return instructions may cause superfluous
increase/decrease of LBR_TOS.
This patch modifies __intel_pmu_lbr_enable() to not enable
FREEZE_LBRS_ON_PMI when LBR operates in callstack mode. We currently
don't use LBR callstack to capture kernel space callchain, so disabling
FREEZE_LBRS_ON_PMI should not be a problem.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-15-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:56:06 +0000 (21:56 -0500)]
perf: Simplify the branch stack check
Use event->attr.branch_sample_type to replace
intel_pmu_needs_lbr_smpl() for avoiding duplicated code that
implicitly enables the LBR.
Currently, branch stack can be enabled by user explicitly requesting
branch sampling or implicit branch sampling to correct PEBS skid.
For user explicitly requested branch sampling, the branch_sample_type
is explicitly set by user. For PEBS case, the branch_sample_type is also
implicitly set to PERF_SAMPLE_BRANCH_ANY in x86_pmu_hw_config.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-11-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:56:05 +0000 (21:56 -0500)]
perf/x86/intel: Save/restore LBR stack during context switch
When the LBR call stack is enabled, it is necessary to save/restore
the LBR stack on context switch. The solution is saving/restoring
the LBR stack to/from task's perf event context.
The LBR stack is saved/restored only when there are events that use
the LBR call stack. If no event uses LBR call stack, the LBR stack
is reset when task is scheduled in.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-10-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:56:04 +0000 (21:56 -0500)]
perf/x86/intel: Track number of events that use the LBR callstack
When enabling/disabling an event, check if the event uses the LBR
callstack feature, adjust the LBR callstack usage count accordingly.
Later patch will use the usage count to decide if LBR stack should
be saved/restored.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-9-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:56:03 +0000 (21:56 -0500)]
perf/x86/intel: Allocate space for storing LBR stack
When the LBR call stack is enabled, it is necessary to save/restore
the LBR stack on context switch. We can use pmu specific data to
store LBR stack when task is scheduled out. This patch adds code
that allocates the pmu specific data.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Stephane Eranian <eranian@google.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-8-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:56:02 +0000 (21:56 -0500)]
perf: Always switch pmu specific data during context switch
If two tasks were both forked from the same parent task, Events in
their perf task contexts can be the same. Perf core may leave out
switching the perf event contexts.
Previous patch inroduces pmu specific data. The data is for saving
the LBR stack, it is task specific. So we need to switch the data
even when context switch is optimized out.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-7-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:56:01 +0000 (21:56 -0500)]
perf: Add pmu specific data for perf task context
Introduce a new flag PERF_ATTACH_TASK_DATA for perf event's attach
stata. The flag is set by PMU's event_init() callback, it indicates
that perf event needs PMU specific data.
The PMU specific data are initialized to zeros. Later patches will
use PMU specific data to save LBR stack.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-6-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:56:00 +0000 (21:56 -0500)]
perf/x86/intel: Add basic Haswell LBR call stack support
Haswell has a new feature that utilizes the existing LBR facility to
record call chains. To enable this feature, bits (JCC, NEAR_IND_JMP,
NEAR_REL_JMP, FAR_BRANCH, EN_CALLSTACK) in LBR_SELECT must be set to 1,
bits (NEAR_REL_CALL, NEAR-IND_CALL, NEAR_RET) must be cleared. Due to
a hardware bug of Haswell, this feature doesn't work well with
FREEZE_LBRS_ON_PMI.
When the call stack feature is enabled, the LBR stack will capture
unfiltered call data normally, but as return instructions are executed,
the last captured branch record is flushed from the on-chip registers
in a last-in first-out (LIFO) manner. Thus, branch information relative
to leaf functions will not be captured, while preserving the call stack
information of the main line execution path.
This patch defines a separate lbr_sel map for Haswell. The map contains
a new entry for the call stack feature.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-5-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:55:59 +0000 (21:55 -0500)]
perf/x86/intel: Use context switch callback to flush LBR stack
Previous commit introduces context switch callback, its function
overlaps with the flush branch stack callback. So we can use the
context switch callback to flush LBR stack.
This patch adds code that uses the flush branch callback to
flush the LBR stack when task is being scheduled in. The callback
is enabled only when there are events use the LBR hardware. This
patch also removes all old flush branch stack code.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-4-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:55:58 +0000 (21:55 -0500)]
perf: Introduce pmu context switch callback
The callback is invoked when process is scheduled in or out.
It provides mechanism for later patches to save/store the LBR
stack. For the schedule in case, the callback is invoked at
the same place that flush branch stack callback is invoked.
So it also can replace the flush branch stack callback. To
avoid unnecessary overhead, the callback is enabled only when
there are events use the LBR stack.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: eranian@google.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1415156173-10035-3-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yan, Zheng [Wed, 5 Nov 2014 02:55:57 +0000 (21:55 -0500)]
perf/x86/intel: Reduce lbr_sel_map[] size
The index of lbr_sel_map is bit value of perf branch_sample_type.
PERF_SAMPLE_BRANCH_MAX is 1024 at present, so each lbr_sel_map uses
4096 bytes. By using bit shift as index, we can reduce lbr_sel_map
size to 40 bytes. This patch defines 'bit shift' for branch types,
and use 'bit shift' to define lbr_sel_maps.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Stephane Eranian <eranian@google.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: jolsa@redhat.com Cc: linux-api@vger.kernel.org Link: http://lkml.kernel.org/r/1415156173-10035-2-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf trace: Print thread info when following children
The default for 'trace workload' is to set perf_event_attr.inherit to 1,
i.e. to make it equivalent to 'strace -f workload', so we were ending
with syscalls for multiple processes mixed up, fix it:
Yunlong Song [Fri, 13 Feb 2015 13:11:55 +0000 (21:11 +0800)]
perf list: Place the header text in its right position
The hearer text 'List of pre-defined events (to be used in -e):' is
placed in an improper function, which causes an abnormal output, e.g.
'perf list hw' shows no guiding text at all, and 'perf list hw
L1-dcache*' shows the guiding text incorrectly in the middle of the
output.
Example
Before this patch:
$ perf list hw L1-dcache*
branch-instructions OR branches [Hardware event]
branch-misses [Hardware event]
bus-cycles [Hardware event]
cache-misses [Hardware event]
cache-references [Hardware event]
cpu-cycles OR cycles [Hardware event]
instructions [Hardware event]
stalled-cycles-backend OR idle-cycles-backend [Hardware event]
stalled-cycles-frontend OR idle-cycles-frontend [Hardware event]
List of pre-defined events (to be used in -e): <-- incorrect position
L1-dcache-load-misses [Hardware cache event]
L1-dcache-loads [Hardware cache event]
L1-dcache-prefetch-misses [Hardware cache event]
L1-dcache-prefetches [Hardware cache event]
L1-dcache-store-misses [Hardware cache event]
L1-dcache-stores [Hardware cache event]
After this patch:
$ perf list hw L1-dcache*
List of pre-defined events (to be used in -e): <-- correct position
branch-instructions OR branches [Hardware event]
branch-misses [Hardware event]
bus-cycles [Hardware event]
cache-misses [Hardware event]
cache-references [Hardware event]
cpu-cycles OR cycles [Hardware event]
instructions [Hardware event]
stalled-cycles-backend OR idle-cycles-backend [Hardware event]
stalled-cycles-frontend OR idle-cycles-frontend [Hardware event]
Kaixu Xia [Tue, 27 Jan 2015 09:55:12 +0000 (17:55 +0800)]
perf: Remove the extra validity check on nr_pages
The function is_power_of_2() also do the check on nr_pages, so the first
check performed is unnecessary. On the other hand, the key point is to
ensure @nr_pages is a power-of-two number and mostly @nr_pages is a
nonzero value, so in the most cases, the function is_power_of_2() will
be called.
Yunlong Song [Fri, 13 Feb 2015 13:11:52 +0000 (21:11 +0800)]
perf tools: Fix a bug of segmentation fault
Fix the 'segmentation fault' bug of 'perf list --list-cmds', which also
happens in other cases (e.g. record, report ...). This bug happens when
there are no cmds to list at all.
Example:
Before this patch:
$ perf list --list-cmds
Segmentation fault
$
After this patch:
$ perf list --list-cmds
$
As shown above, the result prints nothing rather than a segmentation
fault. The null result means 'perf list' has no cmds to display at this
time.
Jiri Olsa [Tue, 30 Dec 2014 13:03:40 +0000 (14:03 +0100)]
perf build: Add arch x86 objects building
Move the x86 arch objects building under build framework to be included
in the libperf build object.
Adding also arch/$(ARCH)/Build files for the rest of the archs. The
reason for this is that in arch/Build we now do:
+libperf-y += $(ARCH)/
which would make the build to fail on other architectures, because the
build framework requires 'Build' file in nested directories and this
patch adds it only for x86.
Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Tested-by: Will Deacon <will.deacon@arm.com> Cc: Alexis Berlemont <alexis.berlemont@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-5enob06z07m7ew6nzzdmp3n2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Jiri Olsa [Wed, 31 Dec 2014 16:37:00 +0000 (17:37 +0100)]
tools build: Add detected config support
Adding support to include detected configuration makefile into the build
process. This will allow the Build objects to be configurable based on
the config data, like:
perf-$(CONFIG_KRAVA) += krava.o
The configuration is stored in '.config-detected' file, which is
generated for each compilation.
Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Tested-by: Will Deacon <will.deacon@arm.com> Cc: Alexis Berlemont <alexis.berlemont@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-bl8qho0ubck7aqrbbfu9inlm@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Josh Boyer [Wed, 11 Feb 2015 16:24:05 +0000 (11:24 -0500)]
perf tools: Define _GNU_SOURCE on pthread_attr_setaffinity_np feature check
The man page for pthread_attr_set_affinity_np states that _GNU_SOURCE
must be defined before pthread.h is included in order to get the proper
function declaration. Define this in the Makefile.
Without this defined, the feature check fails on a Fedora system with
gcc5 and then the perf build later fails with conflicting prototypes for
the function.
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com> Link: http://lkml.kernel.org/r/20150211162404.GA15522@hansolo.redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Consolidate .build-id cache path generating routines to
build_id__filename() function. Other functions must use it to get the
buildid cache path (link path) from build-id. This can reduce the risk
of partial-update.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20150210091853.19264.58513.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Functions related to buildid-cache subcommand use debugdir parameters
for passing buildid cache directory path. However all callers just pass
buildid_dir global variable. Moreover, other functions which refer
buildid cache use buildid_dir directly.
This removes unneeded debugdir parameters from those functions and use
buildid_dir if needed.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20150210091851.19264.72741.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Vinson Lee [Tue, 10 Feb 2015 00:29:37 +0000 (16:29 -0800)]
perf symbols: Define STT_GNU_IFUNC for glibc 2.9 and older.
The token STT_GNU_IFUNC is not available with glibc 2.9 and older.
Define this token if it is not already defined.
This patch fixes this build errors with older versions of glibc.
CC util/symbol-elf.o
util/symbol-elf.c: In function ‘elf_sym__is_function’:
util/symbol-elf.c:75: error: ‘STT_GNU_IFUNC’ undeclared (first use in this function)
util/symbol-elf.c:75: error: (Each undeclared identifier is reported only once
util/symbol-elf.c:75: error: for each function it appears in.)
make: *** [util/symbol-elf.o] Error 1
Signed-off-by: Vinson Lee <vlee@twitter.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Anton Blanchard <anton@samba.org> Cc: Avi Kivity <avi@cloudius-systems.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Waiman Long <Waiman.Long@hp.com> Cc: stable@vger.kernel.org # 3.17+ Link: http://lkml.kernel.org/r/1423528286-13630-1-git-send-email-vlee@twopensource.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As tracefs may be mounted instead of debugfs to get to the event
directories, have perf know about tracefs, and use that file system over
debugfs if it is present.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20150202193553.340946602@goodmis.org
[ Fixed up error messages about tracefs pointed out by Namhyung ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools lib api fs: Add {tracefs,debugfs}_configured() functions
Add tracefs_configured() to return true if tracefs is configured in the
kernel (succeeds to find tracefs), and debugfs_configured() if debugfs
is configured in the kernel (succeeds to find debugfs).
Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20150202193553.190606690@goodmis.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools lib api fs: Add tracefs mount helper functions
Since tracefs will now hold the event directory for perf, and even
though by default, debugfs still mounts tracefs on the debugfs/tracing
directory, the system admin may now choose to not mount debugfs and
instead just mount tracefs instead.
Having tracefs helper functions will facilitate having perf look for
tracefs first, and then try debugfs as a fallback.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20150202193552.898934751@goodmis.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools lib fs: Add helper to find mounted file systems
In preparation for adding tracefs for perf to use, create a findfs
helper utility that find_debugfs uses instead of hard coding the search
in the code. This will allow for a find_tracefs to be used as well.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20150202193552.735023362@goodmis.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tools: Do not check debugfs MAGIC for tracing files
It's rather strange to be checking the debugfs MAGIC number for the
tracing directory. A system admin may want to have a custom set of
events to trace and it should be allowed to let the admin make a temp
file (even for tracing virtual boxes, this is useful).
Also with the coming tracefs, the files may not even be under debugfs,
so checking the debugfs MAGIC number is pointless.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20150202193552.546175764@goodmis.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The existing one, event_format__print() uses stdout unconditionally,
and 'perf trace' needs to use it to format into a file that may have
been set by the user, i.e. 'trace -o file.output'.
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: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/n/tip-7l0mgm91hwg0bby00s5pse8r@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Victor Kamensky [Tue, 27 Jan 2015 06:34:02 +0000 (22:34 -0800)]
perf symbols: debuglink should take symfs option into account
Currently code that tries to read corresponding debug symbol file from
.gnu_debuglink section (DSO_BINARY_TYPE__DEBUGLINK) does not take in
account symfs option, so filename__read_debuglink function cannot open
ELF file, if symfs option is used.
Fix is to add proper handling of symfs as it is done in other places:
use __symbol__join_symfs function to get real file name of target ELF
file.
Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Tested-by: David Ahern <dsahern@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Anton Blanchard <anton@samba.org> Cc: Avi Kivity <avi@cloudius-systems.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Russell King <linux@arm.linux.org.uk> Cc: Waiman Long <Waiman.Long@hp.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1422340442-4673-3-git-send-email-victor.kamensky@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Victor Kamensky [Tue, 27 Jan 2015 06:34:01 +0000 (22:34 -0800)]
perf symbols: Ignore mapping symbols on aarch64
Aarch64 ELF files use mapping symbols with special names $x, $d
to identify regions of Aarch64 code (see Aarch64 ELF ABI - "ARM
IHI 0056B", section "4.5.4 Mapping symbols").
The patch filters out these symbols at load time, similar to
"696b97a perf symbols: Ignore mapping symbols on ARM" changes
done for ARM before V8.
Also added handling of mapping symbols that has format
"$d.<any>" and similar for both cases.
Note we are not making difference between EM_ARM and
EM_AARCH64 mapping symbols instead code handles superset
of both.
Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Anton Blanchard <anton@samba.org> Cc: Avi Kivity <avi@cloudius-systems.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Russell King <linux@arm.linux.org.uk> Link: http://lkml.kernel.org/r/1422340442-4673-2-git-send-email-victor.kamensky@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Masami Hiramatsu [Fri, 30 Jan 2015 09:37:44 +0000 (18:37 +0900)]
perf probe: Fix to handle optimized not-inlined functions
Fix to handle optimized no-inline functions which have only function
definition but no actual instance at that point.
To fix this problem, we need to find actual instance of the function.
Without this patch:
----
# perf probe -a __up
Failed to get entry address of __up.
Error: Failed to add events.
# perf probe -L __up
Specified source line is not found.
Error: Failed to show lines.
----
With this patch:
----
# perf probe -a __up
Added new event:
probe:__up (on __up)
Namhyung Kim [Fri, 30 Jan 2015 02:33:28 +0000 (11:33 +0900)]
perf tests: Do not rely on dso__data_read_offset() to open dso
Do not rely on dso__data_read_offset() will always call dso__data_fd()
internally. With multi-thread support, accessing a fd will be protected
by a lock and it'll cause a huge contention. It can be avoided since we
can skip reading from file if there's a data in the dso cache.
If one needs to call the dso__data_read_offset(), [s]he also needs to
call dso__data_fd() (or set dso->binary_type at least) first like the
dwarf unwind code does.
Namhyung Kim [Fri, 30 Jan 2015 02:33:27 +0000 (11:33 +0900)]
perf test: Fix dso cache testcase
The current dso cache permits to keep dso->data.fd is open under a half
of open file limit. But test__dso_data_cache() sets dso_cnt to limit /
2 + 1 so it'll reach the limit in the loop even though the loop count is
one less than the dso_cnt and it makes the final dso__data_fd() after
the loop meaningless.
I guess the intention was dsos[0]->data.fd is open before the last open
and gets closed after it. So add an assert before the last open.
Andy Lutomirski [Fri, 24 Oct 2014 22:58:13 +0000 (15:58 -0700)]
perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks
While perfmon2 is a sufficiently evil library (it pokes MSRs
directly) that breaking it is fair game, it's still useful, so we
might as well try to support it. This allows users to write 2 to
/sys/devices/cpu/rdpmc to disable all rdpmc protection so that hack
like perfmon2 can continue to work.
At some point, if perf_event becomes fast enough to replace
perfmon2, then this can go.
Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/caac3c1c707dcca48ecbc35f4def21495856f479.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Lutomirski [Fri, 24 Oct 2014 22:58:12 +0000 (15:58 -0700)]
perf/x86: Only allow rdpmc if a perf_event is mapped
We currently allow any process to use rdpmc. This significantly
weakens the protection offered by PR_TSC_DISABLED, and it could be
helpful to users attempting to exploit timing attacks.
Since we can't enable access to individual counters, use a very
coarse heuristic to limit access to rdpmc: allow access only when
a perf_event is mmapped. This protects seccomp sandboxes.
There is plenty of room to further tighen these restrictions. For
example, this allows rdpmc for any x86_pmu event, but it's only
useful for self-monitoring tasks.
As a side effect, cap_user_rdpmc will now be false for AMD uncore
events. This isn't a real regression, since .event_idx is disabled
for these events anyway for the time being. Whenever that gets
re-added, the cap_user_rdpmc code can be adjusted or refactored
accordingly.
Andy Lutomirski [Fri, 24 Oct 2014 22:58:09 +0000 (15:58 -0700)]
x86: Add a comment clarifying LDT context switching
The code is correct, but only for a rather subtle reason. This
confused me for quite a while when I read switch_mm, so clarify the
code to avoid confusing other people, too.
TBH, I wouldn't be surprised if this code was only correct by
accident.
Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/0db86397f968996fb772c443c251415b0b430ddd.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Lutomirski [Fri, 24 Oct 2014 22:58:08 +0000 (15:58 -0700)]
x86: Store a per-cpu shadow copy of CR4
Context switches and TLB flushes can change individual bits of CR4.
CR4 reads take several cycles, so store a shadow copy of CR4 in a
per-cpu variable.
To avoid wasting a cache line, I added the CR4 shadow to
cpu_tlbstate, which is already touched in switch_mm. The heaviest
users of the cr4 shadow will be switch_mm and __switch_to_xtra, and
__switch_to_xtra is called shortly after switch_mm during context
switch, so the cacheline is likely to be hot.
Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/3a54dd3353fffbf84804398e00dfdc5b7c1afd7d.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Lutomirski [Fri, 24 Oct 2014 22:58:07 +0000 (15:58 -0700)]
x86: Clean up cr4 manipulation
CR4 manipulation was split, seemingly at random, between direct
(write_cr4) and using a helper (set/clear_in_cr4). Unfortunately,
the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code,
which only a small subset of users actually wanted.
This patch replaces all cr4 access in functions that don't leave cr4
exactly the way they found it with new helpers cr4_set_bits,
cr4_clear_bits, and cr4_set_bits_and_update_boot.
Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mark Rutland [Wed, 7 Jan 2015 15:01:54 +0000 (15:01 +0000)]
perf: Decouple unthrottling and rotating
Currently the adjusments made as part of perf_event_task_tick() use the
percpu rotation lists to iterate over any active PMU contexts, but these
are not used by the context rotation code, having been replaced by
separate (per-context) hrtimer callbacks. However, some manipulation of
the rotation lists (i.e. removal of contexts) has remained in
perf_rotate_context(). This leads to the following issues:
* Contexts are not always removed from the rotation lists. Removal of
PMUs which have been placed in rotation lists, but have not been
removed by a hrtimer callback can result in corruption of the rotation
lists (when memory backing the context is freed).
This has been observed to result in hangs when PMU drivers built as
modules are inserted and removed around the creation of events for
said PMUs.
* Contexts which do not require rotation may be removed from the
rotation lists as a result of a hrtimer, and will not be considered by
the unthrottling code in perf_event_task_tick.
This patch fixes the issue by updating the rotation ist when events are
scheduled in/out, ensuring that each rotation list stays in sync with
the HW state. As each event holds a refcount on the module of its PMU,
this ensures that when a PMU module is unloaded none of its CPU contexts
can be in a rotation list. By maintaining a list of perf_event_contexts
rather than perf_event_cpu_contexts, we don't need separate paths to
handle the cpu and task contexts, which also makes the code a little
simpler.
As the rotation_list variables are not used for rotation, these are
renamed to active_ctx_list, which better matches their current function.
perf_pmu_rotate_{start,stop} are renamed to
perf_pmu_ctx_{activate,deactivate}.
Reported-by: Johannes Jensen <johannes.jensen@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Will Deacon <Will.Deacon@arm.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20150129134511.GR17721@leverpostej Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mark Rutland [Wed, 7 Jan 2015 14:56:51 +0000 (14:56 +0000)]
perf: Drop module reference on event init failure
When initialising an event, perf_init_event will call try_module_get() to
ensure that the PMU's module cannot be removed for the lifetime of the
event, with __free_event() dropping the reference when the event is
finally destroyed. If something fails after the event has been
initialised, but before the event is installed, perf_event_alloc will
drop the reference on the module.
However, if we fail to initialise an event for some reason (e.g. we ask
an uncore PMU to perform sampling, and it refuses to initialise the
event), we do not drop the refcount. If we try to open such a bogus
event without a precise IDR type, we will loop over each PMU in the pmus
list, incrementing each of their refcounts without decrementing them.
This patch adds a module_put when pmu->event_init(event) fails, ensuring
that the refcounts are balanced in failure cases. As the innards of the
precise and search based initialisation look very similar, this logic is
hoisted out into a new helper function. While the early return for the
failed try_module_get is removed from the search case, this is handled
by the remaining return when ret is not -ENOENT.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1420642611-22667-1-git-send-email-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Thu, 29 Jan 2015 13:44:34 +0000 (14:44 +0100)]
perf: Fix put_event() ctx lock
So what I suspect; but I'm in zombie mode today it seems; is that while
I initially thought that it was impossible for ctx to change when
refcount dropped to 0, I now suspect its possible.
Note that until perf_remove_from_context() the event is still active and
visible on the lists. So a concurrent sys_perf_event_open() from another
task into this task can race.
I think the below should cure this; if we install a group leader it
will iterate the (still intact) group list and find its siblings and
try and install those too -- even though those still have the old
event->ctx -- in the new ctx.
Upon installing the first group sibling we'd try and schedule out the
group and trigger the above warn.
Fix this by installing the group leader last, installing siblings
would have no effect, they're not reachable through the group lists
and therefore we don't schedule them.
Also delay resetting the state until we're absolutely sure the events
are quiescent.
Reported-by: Jiri Olsa <jolsa@redhat.com> Reported-by: vincent.weaver@maine.edu Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20150126162639.GA21418@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
projects / linux-beck.git / log