1. 26 4月, 2007 1 次提交
  2. 08 12月, 2006 8 次提交
  3. 03 12月, 2006 3 次提交
  4. 01 11月, 2006 1 次提交
  5. 30 10月, 2006 2 次提交
  6. 29 10月, 2006 4 次提交
  7. 01 10月, 2006 3 次提交
  8. 23 9月, 2006 1 次提交
  9. 01 8月, 2006 2 次提交
  10. 15 7月, 2006 5 次提交
    • S
      [PATCH] Remove down_write() from taskstats code invoked on the exit() path · bb129994
      Shailabh Nagar 提交于
      In send_cpu_listeners(), which is called on the exit path, a down_write()
      was protecting operations like skb_clone() and genlmsg_unicast() that do
      GFP_KERNEL allocations.  If the oom-killer decides to kill tasks to satisfy
      the allocations,the exit of those tasks could block on the same semphore.
      
      The down_write() was only needed to allow removal of invalid listeners from
      the listener list.  The patch converts the down_write to a down_read and
      defers the removal to a separate critical region.  This ensures that even
      if the oom-killer is called, no other task's exit is blocked as it can
      still acquire another down_read.
      
      Thanks to Andrew Morton & Herbert Xu for pointing out the oom related
      pitfalls, and to Chandra Seetharaman for suggesting this fix instead of
      using something more complex like RCU.
      Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
      Signed-off-by: NShailabh Nagar <nagar@watson.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      bb129994
    • S
      [PATCH] per-task delay accounting taskstats interface: control exit data through cpumasks · f9fd8914
      Shailabh Nagar 提交于
      On systems with a large number of cpus, with even a modest rate of tasks
      exiting per cpu, the volume of taskstats data sent on thread exit can
      overflow a userspace listener's buffers.
      
      One approach to avoiding overflow is to allow listeners to get data for a
      limited and specific set of cpus.  By scaling the number of listeners
      and/or the cpus they monitor, userspace can handle the statistical data
      overload more gracefully.
      
      In this patch, each listener registers to listen to a specific set of cpus
      by specifying a cpumask.  The interest is recorded per-cpu.  When a task
      exits on a cpu, its taskstats data is unicast to each listener interested
      in that cpu.
      
      Thanks to Andrew Morton for pointing out the various scalability and
      general concerns of previous attempts and for suggesting this design.
      
      [akpm@osdl.org: build fix]
      Signed-off-by: NShailabh Nagar <nagar@watson.ibm.com>
      Signed-off-by: NBalbir Singh <balbir@in.ibm.com>
      Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      f9fd8914
    • S
      [PATCH] delay accounting taskstats interface send tgid once · ad4ecbcb
      Shailabh Nagar 提交于
      Send per-tgid data only once during exit of a thread group instead of once
      with each member thread exit.
      
      Currently, when a thread exits, besides its per-tid data, the per-tgid data
      of its thread group is also sent out, if its thread group is non-empty.
      The per-tgid data sent consists of the sum of per-tid stats for all
      *remaining* threads of the thread group.
      
      This patch modifies this sending in two ways:
      
      - the per-tgid data is sent only when the last thread of a thread group
        exits.  This cuts down heavily on the overhead of sending/receiving
        per-tgid data, especially when other exploiters of the taskstats
        interface aren't interested in per-tgid stats
      
      - the semantics of the per-tgid data sent are changed.  Instead of being
        the sum of per-tid data for remaining threads, the value now sent is the
        true total accumalated statistics for all threads that are/were part of
        the thread group.
      
      The patch also addresses a minor issue where failure of one accounting
      subsystem to fill in the taskstats structure was causing the send of
      taskstats to not be sent at all.
      
      The patch has been tested for stability and run cerberus for over 4 hours
      on an SMP.
      
      [akpm@osdl.org: bugfixes]
      Signed-off-by: NShailabh Nagar <nagar@watson.ibm.com>
      Signed-off-by: NBalbir Singh <balbir@in.ibm.com>
      Cc: Jay Lan <jlan@engr.sgi.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      ad4ecbcb
    • S
      [PATCH] per-task-delay-accounting: delay accounting usage of taskstats interface · 6f44993f
      Shailabh Nagar 提交于
      Usage of taskstats interface by delay accounting.
      Signed-off-by: NShailabh Nagar <nagar@us.ibm.com>
      Signed-off-by: NBalbir Singh <balbir@in.ibm.com>
      Cc: Jes Sorensen <jes@sgi.com>
      Cc: Peter Chubb <peterc@gelato.unsw.edu.au>
      Cc: Erich Focht <efocht@ess.nec.de>
      Cc: Levent Serinol <lserinol@gmail.com>
      Cc: Jay Lan <jlan@engr.sgi.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      6f44993f
    • S
      [PATCH] per-task-delay-accounting: taskstats interface · c757249a
      Shailabh Nagar 提交于
      Create a "taskstats" interface based on generic netlink (NETLINK_GENERIC
      family), for getting statistics of tasks and thread groups during their
      lifetime and when they exit.  The interface is intended for use by multiple
      accounting packages though it is being created in the context of delay
      accounting.
      
      This patch creates the interface without populating the fields of the data
      that is sent to the user in response to a command or upon the exit of a task.
      Each accounting package interested in using taskstats has to provide an
      additional patch to add its stats to the common structure.
      
      [akpm@osdl.org: cleanups, Kconfig fix]
      Signed-off-by: NShailabh Nagar <nagar@us.ibm.com>
      Signed-off-by: NBalbir Singh <balbir@in.ibm.com>
      Cc: Jes Sorensen <jes@sgi.com>
      Cc: Peter Chubb <peterc@gelato.unsw.edu.au>
      Cc: Erich Focht <efocht@ess.nec.de>
      Cc: Levent Serinol <lserinol@gmail.com>
      Cc: Jay Lan <jlan@engr.sgi.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      c757249a