talos-op-linux/kernel/cgroup.c, branch v3.2

cgroups: fix a css_set not found bug in cgroup_attach_proc

2011-12-19T17:09:09+00:00

There is a BUG when migrating a PF_EXITING proc. Since css_set_prefetch() is not called for the PF_EXITING case, find_existing_css_set() will return NULL inside cgroup_task_migrate() causing a BUG. This bug is easy to reproduce. Create a zombie and echo its pid to cgroup.procs. $ cat zombie.c \#include int main() { if (fork()) pause(); return 0; } $ We are hitting this bug pretty regularly on ChromeOS. This bug is already fixed by Tejun Heo's cgroup patchset which is targetted for the next merge window: https://lkml.org/lkml/2011/11/1/356 I've create a smaller patch here which just fixes this bug so that a fix can be merged into the current release and stable. Signed-off-by: Mandeep Singh Baines Downstream-Bug-Report: http://crosbug.com/23953 Reviewed-by: Li Zefan Signed-off-by: Tejun Heo Cc: containers@lists.linux-foundation.org Cc: cgroups@vger.kernel.org Cc: stable@kernel.org Cc: KAMEZAWA Hiroyuki Cc: Frederic Weisbecker Cc: Oleg Nesterov Cc: Andrew Morton Cc: Paul Menage Cc: Olof Johansson

memcg: replace ss->id_lock with a rwlock

2011-11-02T23:07:03+00:00

While back-porting Johannes Weiner's patch "mm: memcg-aware global reclaim" for an internal effort, we noticed a significant performance regression during page-reclaim heavy workloads due to high contention of the ss->id_lock. This lock protects idr map, and serializes calls to idr_get_next() in css_get_next() (which is used during the memcg hierarchy walk). Since idr_get_next() is just doing a look up, we need only serialize it with respect to idr_remove()/idr_get_new(). By making the ss->id_lock a rwlock, contention is greatly reduced and performance improves. Tested: cat a 256m file from a ramdisk in a 128m container 50 times on each core (one file + container per core) in parallel on a NUMA machine. Result is the time for the test to complete in 1 of the containers. Both kernels included Johannes' memcg-aware global reclaim patches. Before rwlock patch: 1710.778s After rwlock patch: 152.227s Signed-off-by: Andrew Bresticker Cc: Paul Menage Cc: Li Zefan Acked-by: KAMEZAWA Hiroyuki Cc: Ying Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cgroups: don't attach task to subsystem if migration failed

2011-11-02T23:06:59+00:00

If a task has exited to the point it has called cgroup_exit() already, then we can't migrate it to another cgroup anymore. This can happen when we are attaching a task to a new cgroup between the call to ->can_attach_task() on subsystems and the migration that is eventually tried in cgroup_task_migrate(). In this case cgroup_task_migrate() returns -ESRCH and we don't want to attach the task to the subsystems because the attachment to the new cgroup itself failed. Fix this by only calling ->attach_task() on the subsystems if the cgroup migration succeeded. Reported-by: Oleg Nesterov Signed-off-by: Ben Blum Acked-by: Paul Menage Cc: Li Zefan Cc: Tejun Heo Signed-off-by: Frederic Weisbecker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cgroups: more safe tasklist locking in cgroup_attach_proc

2011-11-02T23:06:59+00:00

Fix unstable tasklist locking in cgroup_attach_proc. According to this thread - https://lkml.org/lkml/2011/7/27/243 - RCU is not sufficient to guarantee the tasklist is stable w.r.t. de_thread and exit. Taking tasklist_lock for reading, instead of rcu_read_lock, ensures proper exclusion. Signed-off-by: Ben Blum Acked-by: Paul Menage Cc: Oleg Nesterov Cc: Frederic Weisbecker Cc: "Paul E. McKenney" Cc: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

locking, sched, cgroups: Annotate release_list_lock as raw

2011-09-13T09:11:49+00:00

The release_list_lock can be taken in atomic context and therefore cannot be preempted on -rt - annotate it. In mainline this change documents the low level nature of the lock - otherwise there's no functional difference. Lockdep and Sparse checking will work as usual. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

2011-07-28T02:26:38+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (54 commits) tpm_nsc: Fix bug when loading multiple TPM drivers tpm: Move tpm_tis_reenable_interrupts out of CONFIG_PNP block tpm: Fix compilation warning when CONFIG_PNP is not defined TOMOYO: Update kernel-doc. tpm: Fix a typo tpm_tis: Probing function for Intel iTPM bug tpm_tis: Fix the probing for interrupts tpm_tis: Delay ACPI S3 suspend while the TPM is busy tpm_tis: Re-enable interrupts upon (S3) resume tpm: Fix display of data in pubek sysfs entry tpm_tis: Add timeouts sysfs entry tpm: Adjust interface timeouts if they are too small tpm: Use interface timeouts returned from the TPM tpm_tis: Introduce durations sysfs entry tpm: Adjust the durations if they are too small tpm: Use durations returned from TPM TOMOYO: Enable conditional ACL. TOMOYO: Allow using argv[]/envp[] of execve() as conditions. TOMOYO: Allow using executable's realpath and symlink's target as conditions. TOMOYO: Allow using owner/group etc. of file objects as conditions. ... Fix up trivial conflict in security/tomoyo/realpath.c

atomic: use

2011-07-26T23:49:47+00:00

This allows us to move duplicated code in (atomic_inc_not_zero() for now) to Signed-off-by: Arun Sharma Reviewed-by: Eric Dumazet Cc: Ingo Molnar Cc: David Miller Cc: Eric Dumazet Acked-by: Mike Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2011-07-25T20:56:39+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits) fs: Merge split strings treewide: fix potentially dangerous trailing ';' in #defined values/expressions uwb: Fix misspelling of neighbourhood in comment net, netfilter: Remove redundant goto in ebt_ulog_packet trivial: don't touch files that are removed in the staging tree lib/vsprintf: replace link to Draft by final RFC number doc: Kconfig: `to be' -> `be' doc: Kconfig: Typo: square -> squared doc: Konfig: Documentation/power/{pm => apm-acpi}.txt drivers/net: static should be at beginning of declaration drivers/media: static should be at beginning of declaration drivers/i2c: static should be at beginning of declaration XTENSA: static should be at beginning of declaration SH: static should be at beginning of declaration MIPS: static should be at beginning of declaration ARM: static should be at beginning of declaration rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check Update my e-mail address PCIe ASPM: forcedly -> forcibly gma500: push through device driver tree ... Fix up trivial conflicts: - arch/arm/mach-ep93xx/dma-m2p.c (deleted) - drivers/gpio/gpio-ep93xx.c (renamed and context nearby) - drivers/net/r8169.c (just context changes)

kill file_permission() completely

2011-07-20T05:43:11+00:00

convert the last remaining caller to inode_permission() Signed-off-by: Al Viro

rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check

2011-07-08T20:21:58+00:00

Since ca5ecddf (rcu: define __rcu address space modifier for sparse) rcu_dereference_check use rcu_read_lock_held as a part of condition automatically so callers do not have to do that as well. Signed-off-by: Michal Hocko Acked-by: Paul E. McKenney Signed-off-by: Jiri Kosina