1. 20 12月, 2007 1 次提交
  2. 17 10月, 2007 1 次提交
    • N
      core_pattern: ignore RLIMIT_CORE if core_pattern is a pipe · 7dc0b22e
      Neil Horman 提交于
      For some time /proc/sys/kernel/core_pattern has been able to set its output
      destination as a pipe, allowing a user space helper to receive and
      intellegently process a core.  This infrastructure however has some
      shortcommings which can be enhanced.  Specifically:
      
      1) The coredump code in the kernel should ignore RLIMIT_CORE limitation
         when core_pattern is a pipe, since file system resources are not being
         consumed in this case, unless the user application wishes to save the core,
         at which point the app is restricted by usual file system limits and
         restrictions.
      
      2) The core_pattern code should be able to parse and pass options to the
         user space helper as an argv array.  The real core limit of the uid of the
         crashing proces should also be passable to the user space helper (since it
         is overridden to zero when called).
      
      3) Some miscellaneous bugs need to be cleaned up (specifically the
         recognition of a recursive core dump, should the user mode helper itself
         crash.  Also, the core dump code in the kernel should not wait for the user
         mode helper to exit, since the same context is responsible for writing to
         the pipe, and a read of the pipe by the user mode helper will result in a
         deadlock.
      
      This patch:
      
      Remove the check of RLIMIT_CORE if core_pattern is a pipe.  In the event that
      core_pattern is a pipe, the entire core will be fed to the user mode helper.
      Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
      Cc: <martin.pitt@ubuntu.com>
      Cc: <wwoods@redhat.com>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7dc0b22e
  3. 09 12月, 2006 1 次提交
  4. 30 9月, 2006 1 次提交
  5. 11 1月, 2006 1 次提交
  6. 30 10月, 2005 1 次提交
  7. 22 6月, 2005 1 次提交
    • W
      [PATCH] Avoiding mmap fragmentation · 1363c3cd
      Wolfgang Wander 提交于
      Ingo recently introduced a great speedup for allocating new mmaps using the
      free_area_cache pointer which boosts the specweb SSL benchmark by 4-5% and
      causes huge performance increases in thread creation.
      
      The downside of this patch is that it does lead to fragmentation in the
      mmap-ed areas (visible via /proc/self/maps), such that some applications
      that work fine under 2.4 kernels quickly run out of memory on any 2.6
      kernel.
      
      The problem is twofold:
      
        1) the free_area_cache is used to continue a search for memory where
           the last search ended.  Before the change new areas were always
           searched from the base address on.
      
           So now new small areas are cluttering holes of all sizes
           throughout the whole mmap-able region whereas before small holes
           tended to close holes near the base leaving holes far from the base
           large and available for larger requests.
      
        2) the free_area_cache also is set to the location of the last
           munmap-ed area so in scenarios where we allocate e.g.  five regions of
           1K each, then free regions 4 2 3 in this order the next request for 1K
           will be placed in the position of the old region 3, whereas before we
           appended it to the still active region 1, placing it at the location
           of the old region 2.  Before we had 1 free region of 2K, now we only
           get two free regions of 1K -> fragmentation.
      
      The patch addresses thes issues by introducing yet another cache descriptor
      cached_hole_size that contains the largest known hole size below the
      current free_area_cache.  If a new request comes in the size is compared
      against the cached_hole_size and if the request can be filled with a hole
      below free_area_cache the search is started from the base instead.
      
      The results look promising: Whereas 2.6.12-rc4 fragments quickly and my
      (earlier posted) leakme.c test program terminates after 50000+ iterations
      with 96 distinct and fragmented maps in /proc/self/maps it performs nicely
      (as expected) with thread creation, Ingo's test_str02 with 20000 threads
      requires 0.7s system time.
      
      Taking out Ingo's patch (un-patch available per request) by basically
      deleting all mentions of free_area_cache from the kernel and starting the
      search for new memory always at the respective bases we observe: leakme
      terminates successfully with 11 distinctive hardly fragmented areas in
      /proc/self/maps but thread creating is gringdingly slow: 30+s(!) system
      time for Ingo's test_str02 with 20000 threads.
      
      Now - drumroll ;-) the appended patch works fine with leakme: it ends with
      only 7 distinct areas in /proc/self/maps and also thread creation seems
      sufficiently fast with 0.71s for 20000 threads.
      Signed-off-by: NWolfgang Wander <wwc@rentec.com>
      Credit-to: "Richard Purdie" <rpurdie@rpsys.net>
      Signed-off-by: NKen Chen <kenneth.w.chen@intel.com>
      Acked-by: Ingo Molnar <mingo@elte.hu> (partly)
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      1363c3cd
  8. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds 提交于
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4