kernel/linux.git/include/linux/sched.h, branch linux-2.6.28.y

sched: do not count frozen tasks toward load

2009-05-02T17:56:49+00:00

upstream commit: e3c8ca8336707062f3f7cb1cd7e6b3c753baccdd Freezing tasks via the cgroup freezer causes the load average to climb because the freezer's current implementation puts frozen tasks in uninterruptible sleep (D state). Some applications which perform job-scheduling functions consult the load average when making decisions. If a cgroup is frozen, the load average does not provide a useful measure of the system's utilization to such applications. This is especially inconvenient if the job scheduler employs the cgroup freezer as a mechanism for preempting low priority jobs. Contrast this with using SIGSTOP for the same purpose: the stopped tasks do not count toward system load. Change task_contributes_to_load() to return false if the task is frozen. This results in /proc/loadavg behavior that better meets users' expectations. Signed-off-by: Nathan Lynch Acked-by: Andrew Morton Acked-by: Nigel Cunningham Tested-by: Nigel Cunningham Cc: containers@lists.linux-foundation.org Cc: linux-pm@lists.linux-foundation.org Cc: Matt Helsley LKML-Reference: <20090408194512.47a99b95@manatee.lan> Signed-off-by: Ingo Molnar Signed-off-by: Chris Wright Signed-off-by: Greg Kroah-Hartman

epoll: drop max_user_instances and rely only on max_user_watches

2009-02-02T17:53:26+00:00

commit 9df04e1f25effde823a600e755b51475d438f56b upstream. Linus suggested to put limits where the money is, and max_user_watches already does that w/out the need of max_user_instances. That has the advantage to mitigate the potential DoS while allowing pretty generous default behavior. Allowing top 4% of low memory (per user) to be allocated in epoll watches, we have: LOMEM MAX_WATCHES (per user) 512MB ~178000 1GB ~356000 2GB ~712000 A box with 512MB of lomem, will meet some challenge in hitting 180K watches, socket buffers math teaches us. No more max_user_instances limits then. Signed-off-by: Davide Libenzi Cc: Willy Tarreau Cc: Michael Kerrisk Cc: Bron Gondwana Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

epoll: introduce resource usage limits

2008-12-02T03:55:24+00:00

It has been thought that the per-user file descriptors limit would also limit the resources that a normal user can request via the epoll interface. Vegard Nossum reported a very simple program (a modified version attached) that can make a normal user to request a pretty large amount of kernel memory, well within the its maximum number of fds. To solve such problem, default limits are now imposed, and /proc based configuration has been introduced. A new directory has been created, named /proc/sys/fs/epoll/ and inside there, there are two configuration points: max_user_instances = Maximum number of devices - per user max_user_watches = Maximum number of "watched" fds - per user The current default for "max_user_watches" limits the memory used by epoll to store "watches", to 1/32 of the amount of the low RAM. As example, a 256MB 32bit machine, will have "max_user_watches" set to roughly 90000. That should be enough to not break existing heavy epoll users. The default value for "max_user_instances" is set to 128, that should be enough too. This also changes the userspace, because a new error code can now come out from EPOLL_CTL_ADD (-ENOSPC). The EMFILE from epoll_create() was already listed, so that should be ok. [akpm@linux-foundation.org: use get_current_user()] Signed-off-by: Davide Libenzi Cc: Michael Kerrisk Cc: Cc: Cyrill Gorcunov Reported-by: Vegard Nossum Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fix for account_group_exec_runtime(), make sure ->signal can't be freed under rq->lock

2008-11-11T07:01:43+00:00

Impact: fix hang/crash on ia64 under high load This is ugly, but the simplest patch by far. Unlike other similar routines, account_group_exec_runtime() could be called "implicitly" from within scheduler after exit_notify(). This means we can race with the parent doing release_task(), we can't just check ->signal != NULL. Change __exit_signal() to do spin_unlock_wait(&task_rq(tsk)->lock) before __cleanup_signal() to make sure ->signal can't be freed under task_rq(tsk)->lock. Note that task_rq_unlock_wait() doesn't care about the case when tsk changes cpu/rq under us, this should be OK. Thanks to Ingo who nacked my previous buggy patch. Signed-off-by: Oleg Nesterov Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar Reported-by: Doug Chapman

net: Fix recursive descent in __scm_destroy().

2008-11-06T21:51:50+00:00

__scm_destroy() walks the list of file descriptors in the scm_fp_list pointed to by the scm_cookie argument. Those, in turn, can close sockets and invoke __scm_destroy() again. There is nothing which limits how deeply this can occur. The idea for how to fix this is from Linus. Basically, we do all of the fput()s at the top level by collecting all of the scm_fp_list objects hit by an fput(). Inside of the initial __scm_destroy() we keep running the list until it is empty. Signed-off-by: David S. Miller Signed-off-by: Linus Torvalds

Merge commit 'v2.6.28-rc1' into sched/urgent

2008-10-24T10:48:46+00:00

Merge branch 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc

2008-10-23T19:04:37+00:00

* 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc: (35 commits) proc: remove fs/proc/proc_misc.c proc: move /proc/vmcore creation to fs/proc/vmcore.c proc: move pagecount stuff to fs/proc/page.c proc: move all /proc/kcore stuff to fs/proc/kcore.c proc: move /proc/schedstat boilerplate to kernel/sched_stats.h proc: move /proc/modules boilerplate to kernel/module.c proc: move /proc/diskstats boilerplate to block/genhd.c proc: move /proc/zoneinfo boilerplate to mm/vmstat.c proc: move /proc/vmstat boilerplate to mm/vmstat.c proc: move /proc/pagetypeinfo boilerplate to mm/vmstat.c proc: move /proc/buddyinfo boilerplate to mm/vmstat.c proc: move /proc/vmallocinfo to mm/vmalloc.c proc: move /proc/slabinfo boilerplate to mm/slub.c, mm/slab.c proc: move /proc/slab_allocators boilerplate to mm/slab.c proc: move /proc/interrupts boilerplate code to fs/proc/interrupts.c proc: move /proc/stat to fs/proc/stat.c proc: move rest of /proc/partitions code to block/genhd.c proc: move /proc/cpuinfo code to fs/proc/cpuinfo.c proc: move /proc/devices code to fs/proc/devices.c proc: move rest of /proc/locks to fs/locks.c ...

Merge branch 'v28-range-hrtimers-for-linus-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2008-10-23T17:53:02+00:00

* 'v28-range-hrtimers-for-linus-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (37 commits) hrtimers: add missing docbook comments to struct hrtimer hrtimers: simplify hrtimer_peek_ahead_timers() hrtimers: fix docbook comments DECLARE_PER_CPU needs linux/percpu.h hrtimers: fix typo rangetimers: fix the bug reported by Ingo for real rangetimer: fix BUG_ON reported by Ingo rangetimer: fix x86 build failure for the !HRTIMERS case select: fix alpha OSF wrapper select: fix alpha OSF wrapper hrtimer: peek at the timer queue just before going idle hrtimer: make the futex() system call use the per process slack value hrtimer: make the nanosleep() syscall use the per process slack hrtimer: fix signed/unsigned bug in slack estimator hrtimer: show the timer ranges in /proc/timer_list hrtimer: incorporate feedback from Peter Zijlstra hrtimer: add a hrtimer_start_range() function hrtimer: another build fix hrtimer: fix build bug found by Ingo hrtimer: make select() and poll() use the hrtimer range feature ...

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2008-10-23T16:37:16+00:00

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: disable the hrtick for now sched: revert back to per-rq vruntime sched: fair scheduler should not resched rt tasks sched: optimize group load balancer sched: minor fast-path overhead reduction sched: fix the wrong mask_len, cleanup sched: kill unused scheduler decl. sched: fix the wrong mask_len sched: only update rq->clock while holding rq->lock

proc: move /proc/schedstat boilerplate to kernel/sched_stats.h

2008-10-23T14:06:12+00:00

Signed-off-by: Alexey Dobriyan