Glauber Costa [Thu, 18 Jul 2013 23:59:51 +0000 (09:59 +1000)]
super: fix calculation of shrinkable objects for small numbers
The sysctl knob sysctl_vfs_cache_pressure is used to determine which
percentage of the shrinkable objects in our cache we should actively try
to shrink.
It works great in situations in which we have many objects (at least more
than 100), because the aproximation errors will be negligible. But if
this is not the case, specially when total_objects < 100, we may end up
concluding that we have no objects at all (total / 100 = 0, if total <
100).
This is certainly not the biggest killer in the world, but may matter in
very low kernel memory situations.
Signed-off-by: Glauber Costa <glommer@openvz.org> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Rientjes <rientjes@google.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: J. Bruce Fields <bfields@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Glauber Costa [Thu, 18 Jul 2013 23:59:51 +0000 (09:59 +1000)]
fs: bump inode and dentry counters to long
This series reworks our current object cache shrinking infrastructure in
two main ways:
* Noticing that a lot of users copy and paste their own version of LRU
lists for objects, we put some effort in providing a generic version.
It is modeled after the filesystem users: dentries, inodes, and xfs
(for various tasks), but we expect that other users could benefit in
the near future with little or no modification. Let us know if you
have any issues.
* The underlying list_lru being proposed automatically and
transparently keeps the elements in per-node lists, and is able to
manipulate the node lists individually. Given this infrastructure, we
are able to modify the up-to-now hammer called shrink_slab to proceed
with node-reclaim instead of always searching memory from all over like
it has been doing.
Per-node lru lists are also expected to lead to less contention in the lru
locks on multi-node scans, since we are now no longer fighting for a
global lock. The locks usually disappear from the profilers with this
change.
Although we have no official benchmarks for this version - be our guest to
independently evaluate this - earlier versions of this series were
performance tested (details at
http://permalink.gmane.org/gmane.linux.kernel.mm/100537) yielding no
visible performance regressions while yielding a better qualitative
behavior in NUMA machines.
With this infrastructure in place, we can use the list_lru entry point to
provide memcg isolation and per-memcg targeted reclaim. Historically,
those two pieces of work have been posted together. This version presents
only the infrastructure work, deferring the memcg work for a later time,
so we can focus on getting this part tested. You can see more about the
history of such work at http://lwn.net/Articles/552769/
Dave Chinner (18):
dcache: convert dentry_stat.nr_unused to per-cpu counters
dentry: move to per-sb LRU locks
dcache: remove dentries from LRU before putting on dispose list
mm: new shrinker API
shrinker: convert superblock shrinkers to new API
list: add a new LRU list type
inode: convert inode lru list to generic lru list code.
dcache: convert to use new lru list infrastructure
list_lru: per-node list infrastructure
shrinker: add node awareness
fs: convert inode and dentry shrinking to be node aware
xfs: convert buftarg LRU to generic code
xfs: rework buffer dispose list tracking
xfs: convert dquot cache lru to list_lru
fs: convert fs shrinkers to new scan/count API
drivers: convert shrinkers to new count/scan API
shrinker: convert remaining shrinkers to count/scan API
shrinker: Kill old ->shrink API.
Glauber Costa (7):
fs: bump inode and dentry counters to long
super: fix calculation of shrinkable objects for small numbers
list_lru: per-node API
vmscan: per-node deferred work
i915: bail out earlier when shrinker cannot acquire mutex
hugepage: convert huge zero page shrinker to new shrinker API
list_lru: dynamically adjust node arrays
This patch:
There are situations in very large machines in which we can have a large
quantity of dirty inodes, unused dentries, etc. This is particularly true
when umounting a filesystem, where eventually since every live object will
eventually be discarded.
Dave Chinner reported a problem with this while experimenting with the
shrinker revamp patchset. So we believe it is time for a change. This
patch just moves int to longs. Machines where it matters should have a
big long anyway.
Signed-off-by: Glauber Costa <glommer@openvz.org> Cc: Dave Chinner <dchinner@redhat.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Chinner <dchinner@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: J. Bruce Fields <bfields@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peng Tao [Thu, 18 Jul 2013 23:57:00 +0000 (09:57 +1000)]
staging/lustre: replace num_physpages with totalram_pages
The global variable num_physpages is going away. Replace it
with totalram_pages.
Signed-off-by: Peng Tao <tao.peng@emc.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <dchinner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peng Tao [Thu, 18 Jul 2013 23:57:00 +0000 (09:57 +1000)]
staging/lustre/libcfs: cleanup linux-mem.h
remove shrinker related wrappers.
Signed-off-by: Peng Tao <tao.peng@emc.com> Signed-off-by: Andreas Dilger <andreas.dilger@intel.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <dchinner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peng Tao [Thu, 18 Jul 2013 23:56:59 +0000 (09:56 +1000)]
staging/lustre/ptlrpc: convert to new shrinker API
Convert sptlrpc encode pool shrinker to use scan/count API.
Signed-off-by: Peng Tao <tao.peng@emc.com> Signed-off-by: Andreas Dilger <andreas.dilger@intel.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <dchinner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peng Tao [Thu, 18 Jul 2013 23:56:59 +0000 (09:56 +1000)]
staging/lustre/obdclass: convert lu_object shrinker to count/scan API
convert lu_object shrinker to new count/scan API.
Signed-off-by: Peng Tao <tao.peng@emc.com> Signed-off-by: Andreas Dilger <andreas.dilger@intel.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <dchinner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peng Tao [Thu, 18 Jul 2013 23:56:59 +0000 (09:56 +1000)]
staging/lustre/ldlm: convert to shrinkers to count/scan API
convert ldlm shrinker to new count/scan API.
Signed-off-by: Peng Tao <tao.peng@emc.com> Signed-off-by: Andreas Dilger <andreas.dilger@intel.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <dchinner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As suggested by Andrew, add a generic initial locking scheme used
throughout all sysv ipc mechanisms. Documenting the ids rwsem, how rcu
can be enough to do the initial checks and when to actually acquire the
kern_ipc_perm.lock spinlock.
I found that adding it to util.c was generic enough.
Clean up some of the messy do_shmat() spaghetti code, getting rid of
out_free and out_put_dentry labels. This makes shortening the critical
region of this function in the next patch a little easier to do and read.
With the *_INFO, *_STAT, IPC_RMID and IPC_SET commands already optimized,
deal with the remaining SHM_LOCK and SHM_UNLOCK commands. Take the
shm_perm lock after doing the initial auditing and security checks. The
rest of the logic remains unchanged.
While the INFO cmd doesn't take the ipc lock, the STAT commands do acquire
it unnecessarily. We can do the permissions and security checks only
holding the rcu lock.
Similar to semctl and msgctl, when calling msgctl, the *_INFO and *_STAT
commands can be performed without acquiring the ipc object.
Add a shmctl_nolock() function and move the logic of *_INFO and *_STAT out
of msgctl(). Since we are just moving functionality, this change still
takes the lock and it will be properly lockless in the next patch.
ipc,shm: introduce lockless functions to obtain the ipc object
This is the third and final patchset that deals with reducing the amount
of contention we impose on the ipc lock (kern_ipc_perm.lock). These
changes mostly deal with shared memory, previous work has already been
done for semaphores and message queues:
With these patches applied, a custom shm microbenchmark stressing shmctl
doing IPC_STAT with 4 threads a million times, reduces the execution time
by 50%. A similar run, this time with IPC_SET, reduces the execution time
from 3 mins and 35 secs to 27 seconds.
Patches 1-8: replaces blindly taking the ipc lock for a smarter combination
of rcu and ipc_obtain_object, only acquiring the spinlock when updating.
Patch 9: renames the ids rw_mutex to rwsem, which is what it already was.
Patch 10: is a trivial mqueue leftover cleanup
Patch 11: adds a brief lock scheme description, requested by Andrew.
This patch:
Add shm_obtain_object() and shm_obtain_object_check(), which will allow us
to get the ipc object without acquiring the lock. Just as with other
forms of ipc, these functions are basically wrappers around
ipc_obtain_object*().
When I'm using below ktap script to trace all event tracepoints, without
this patch, the system will hang in few seconds, the patch indeed fix the
problem as the changelog pointed.
This patch is old, I can found the original patch discussion in 2007.
http://marc.info/?l=linux-kernel&m=118544794717162&w=2 (In that mail
thread, the patch didn't fix that problem, but it fix the problem I
encountered now)
Ingo's original changelog:
Remove timer calls (!!!) from deep within the tracing infrastructure.
This was totally bogus code that can cause lockups and worse.
Poll the buffer every 2 jiffies for now.
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: "zhangwei(Jovi)" <jovi.zhangwei@huawei.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
signals: eventpoll: set ->saved_sigmask at the start
task_struct->saved_sigmask has no meaning unless we return with
set_restore_sigmask() and nobody except current can use it.
This means that sys_epoll_pwait() doesn't need to save ->blocked
into the local var and then memcopy it into ->saved_sigmask, we
can simply set ->saved_sigmask right before set_current_blocked().
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eric Wong <normalperson@yhbt.net> Cc: Jason Baron <jbaron@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Implement preallocation via the fallocate syscall on VFAT partitions.
With FALLOC_FL_KEEP_SIZE, there is no way to distinguish if the mismatch
between i_size and no. of clusters allocated is a consequence of
fallocate or just plain corruption. When a non fallocate aware (old)
linux fat driver tries to write to such a file, it throws an error.Also,
fsck detects this as inconsistency and truncates the prealloc'd blocks.
To avoid this, as suggested by OGAWA, remove changes that make fallocate
persistent across mounts and restrict lifetime of blocks from fallocate(2)
to file release.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Ravishankar N <ravi.n1@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / karo-tx-linux.git / log