1. 27 Apr, 2018 1 commit
  2. 16 Jan, 2018 1 commit
    • Josh Snyder's avatar
      delayacct: Account blkio completion on the correct task · c96f5471
      Josh Snyder authored
      Before commit:
      
        e33a9bba ("sched/core: move IO scheduling accounting from io_schedule_timeout() into scheduler")
      
      delayacct_blkio_end() was called after context-switching into the task which
      completed I/O.
      
      This resulted in double counting: the task would account a delay both waiting
      for I/O and for time spent in the runqueue.
      
      With e33a9bba, delayacct_blkio_end() is called by try_to_wake_up().
      In ttwu, we have not yet context-switched. This is more correct, in that
      the delay accounting ends when the I/O is complete.
      
      But delayacct_blkio_end() relies on 'get_current()', and we have not yet
      context-switched into the task whose I/O completed. This results in the
      wrong task having its delay accounting statistics updated.
      
      Instead of doing that, pass the task_struct being woken to delayacct_blkio_end(),
      so that it can update the statistics of the correct task.
      Signed-off-by: 's avatarJosh Snyder <joshs@netflix.com>
      Acked-by: 's avatarTejun Heo <tj@kernel.org>
      Acked-by: 's avatarBalbir Singh <bsingharora@gmail.com>
      Cc: <stable@vger.kernel.org>
      Cc: Brendan Gregg <bgregg@netflix.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-block@vger.kernel.org
      Fixes: e33a9bba ("sched/core: move IO scheduling accounting from io_schedule_timeout() into scheduler")
      Link: http://lkml.kernel.org/r/1513613712-571-1-git-send-email-joshs@netflix.comSigned-off-by: 's avatarIngo Molnar <mingo@kernel.org>
      c96f5471
  3. 02 Mar, 2017 2 commits
  4. 01 Feb, 2017 2 commits
  5. 15 Jan, 2016 1 commit
    • Vladimir Davydov's avatar
      kmemcg: account certain kmem allocations to memcg · 5d097056
      Vladimir Davydov authored
      Mark those kmem allocations that are known to be easily triggered from
      userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
      memcg.  For the list, see below:
      
       - threadinfo
       - task_struct
       - task_delay_info
       - pid
       - cred
       - mm_struct
       - vm_area_struct and vm_region (nommu)
       - anon_vma and anon_vma_chain
       - signal_struct
       - sighand_struct
       - fs_struct
       - files_struct
       - fdtable and fdtable->full_fds_bits
       - dentry and external_name
       - inode for all filesystems. This is the most tedious part, because
         most filesystems overwrite the alloc_inode method.
      
      The list is far from complete, so feel free to add more objects.
      Nevertheless, it should be close to "account everything" approach and
      keep most workloads within bounds.  Malevolent users will be able to
      breach the limit, but this was possible even with the former "account
      everything" approach (simply because it did not account everything in
      fact).
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: 's avatarVladimir Davydov <vdavydov@virtuozzo.com>
      Acked-by: 's avatarJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: 's avatarMichal Hocko <mhocko@suse.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Greg Thelen <gthelen@google.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      5d097056
  6. 23 Jul, 2014 2 commits
  7. 12 Jun, 2014 1 commit
  8. 13 Nov, 2013 1 commit
  9. 27 Jan, 2013 1 commit
    • Frederic Weisbecker's avatar
      cputime: Use accessors to read task cputime stats · 6fac4829
      Frederic Weisbecker authored
      This is in preparation for the full dynticks feature. While
      remotely reading the cputime of a task running in a full
      dynticks CPU, we'll need to do some extra-computation. This
      way we can account the time it spent tickless in userspace
      since its last cputime snapshot.
      Signed-off-by: 's avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      6fac4829
  10. 14 Jul, 2011 1 commit
    • Glauber Costa's avatar
      KVM: Steal time implementation · c9aaa895
      Glauber Costa authored
      To implement steal time, we need the hypervisor to pass the guest
      information about how much time was spent running other processes
      outside the VM, while the vcpu had meaningful work to do - halt
      time does not count.
      
      This information is acquired through the run_delay field of
      delayacct/schedstats infrastructure, that counts time spent in a
      runqueue but not running.
      
      Steal time is a per-cpu information, so the traditional MSR-based
      infrastructure is used. A new msr, KVM_MSR_STEAL_TIME, holds the
      memory area address containing information about steal time
      
      This patch contains the hypervisor part of the steal time infrasructure,
      and can be backported independently of the guest portion.
      
      [avi, yongjie: export delayacct_on, to avoid build failures in some configs]
      Signed-off-by: 's avatarGlauber Costa <glommer@redhat.com>
      Tested-by: 's avatarEric B Munson <emunson@mgebm.net>
      CC: Rik van Riel <riel@redhat.com>
      CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      CC: Peter Zijlstra <peterz@infradead.org>
      CC: Anthony Liguori <aliguori@us.ibm.com>
      Signed-off-by: 's avatarYongjie Ren <yongjie.ren@intel.com>
      Signed-off-by: 's avatarAvi Kivity <avi@redhat.com>
      c9aaa895
  11. 18 Sep, 2009 1 commit
  12. 18 Dec, 2008 1 commit
  13. 25 Jul, 2008 2 commits
    • Keika Kobayashi's avatar
      per-task-delay-accounting: update taskstats for memory reclaim delay · 016ae219
      Keika Kobayashi authored
      Add members for memory reclaim delay to taskstats, and accumulate them in
      __delayacct_add_tsk() .
      Signed-off-by: 's avatarKeika Kobayashi <kobayashi.kk@ncos.nec.co.jp>
      Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
      Cc: Balbir Singh <balbir@in.ibm.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      016ae219
    • Keika Kobayashi's avatar
      per-task-delay-accounting: add memory reclaim delay · 873b4771
      Keika Kobayashi authored
      Sometimes, application responses become bad under heavy memory load.
      Applications take a bit time to reclaim memory.  The statistics, how long
      memory reclaim takes, will be useful to measure memory usage.
      
      This patch adds accounting memory reclaim to per-task-delay-accounting for
      accounting the time of do_try_to_free_pages().
      
      <i.e>
      
      - When System is under low memory load,
        memory reclaim may not occur.
      
      $ free
                   total       used       free     shared    buffers     cached
      Mem:       8197800    1577300    6620500          0       4808    1516724
      -/+ buffers/cache:      55768    8142032
      Swap:     16386292          0   16386292
      
      $ vmstat 1
      procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
       r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
       0  0      0 5069748  10612 3014060    0    0     0     0    3   26  0  0 100  0
       0  0      0 5069748  10612 3014060    0    0     0     0    4   22  0  0 100  0
       0  0      0 5069748  10612 3014060    0    0     0     0    3   18  0  0 100  0
      
      Measure the time of tar command.
      
      $ ls -s test.dat
      1501472 test.dat
      
      $ time tar cvf test.tar test.dat
      real    0m13.388s
      user    0m0.116s
      sys     0m5.304s
      
      $ ./delayget -d -p <pid>
      CPU             count     real total  virtual total    delay total
                        428     5528345500     5477116080       62749891
      IO              count    delay total
                        338     8078977189
      SWAP            count    delay total
                          0              0
      RECLAIM         count    delay total
                          0              0
      
      - When system is under heavy memory load
        memory reclaim may occur.
      
      $ vmstat 1
      procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
       r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
       0  0 7159032  49724   1812   3012    0    0     0     0    3   24  0  0 100  0
       0  0 7159032  49724   1812   3012    0    0     0     0    4   24  0  0 100  0
       0  0 7159032  49848   1812   3012    0    0     0     0    3   22  0  0 100  0
      
      In this case, one process uses more 8G memory
      by execution of malloc() and memset().
      
      $ time tar cvf test.tar test.dat
      real    1m38.563s        <-  increased by 85 sec
      user    0m0.140s
      sys     0m7.060s
      
      $ ./delayget -d -p <pid>
      CPU             count     real total  virtual total    delay total
                       9021     7140446250     7315277975      923201824
      IO              count    delay total
                       8965    90466349669
      SWAP            count    delay total
                          3       21036367
      RECLAIM         count    delay total
                        740    61011951153
      
      In the later case, the value of RECLAIM is increasing.
      So, taskstats can show how much memory reclaim influences TAT.
      Signed-off-by: 's avatarKeika Kobayashi <kobayashi.kk@ncos.nec.co.jp>
      Acked-by: 's avatarBalbir Singh <balbir@linux.vnet.ibm.com>
      Acked-by: 's avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujistu.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      873b4771
  14. 18 Oct, 2007 1 commit
  15. 15 Oct, 2007 1 commit
  16. 09 Jul, 2007 1 commit
  17. 07 May, 2007 1 commit
  18. 07 Dec, 2006 2 commits
  19. 06 Nov, 2006 1 commit
  20. 01 Sep, 2006 1 commit
    • Shailabh Nagar's avatar
      [PATCH] task delay accounting fixes · 35df17c5
      Shailabh Nagar authored
      Cleanup allocation and freeing of tsk->delays used by delay accounting.
      This solves two problems reported for delay accounting:
      
      1. oops in __delayacct_blkio_ticks
      http://www.uwsg.indiana.edu/hypermail/linux/kernel/0608.2/1844.html
      
      Currently tsk->delays is getting freed too early in task exit which can
      cause a NULL tsk->delays to get accessed via reading of /proc/<tgid>/stats.
       The patch fixes this problem by freeing tsk->delays closer to when
      task_struct itself is freed up.  As a result, it also eliminates the use of
      tsk->delays_lock which was only being used (inadequately) to safeguard
      access to tsk->delays while a task was exiting.
      
      2. Possible memory leak in kernel/delayacct.c
      http://www.uwsg.indiana.edu/hypermail/linux/kernel/0608.2/1389.html
      
      The patch cleans up tsk->delays allocations after a bad fork which was
      missing earlier.
      
      The patch has been tested to fix the problems listed above and stress
      tested with rapid calls to delay accounting's taskstats command interface
      (which is the other path that can access the same data, besides the /proc
      interface causing the oops above).
      Signed-off-by: 's avatarShailabh Nagar <nagar@watson.ibm.com>
      Cc: Balbir Singh <balbir@in.ibm.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@osdl.org>
      35df17c5
  21. 31 Jul, 2006 1 commit
  22. 15 Jul, 2006 4 commits