1. 10 9月, 2005 1 次提交
  2. 04 9月, 2005 1 次提交
  3. 02 9月, 2005 1 次提交
  4. 01 9月, 2005 3 次提交
  5. 30 8月, 2005 1 次提交
    • D
      [ARM] 2853/1: Make alloc_init_supersection() work with 36-bit mappings · 083bc6b3
      Deepak Saxena 提交于
      Patch from Deepak Saxena
      
      Working on adding support for 36-bit static mappings for ARMv6 and
      Intel's XSC3 core and noticed that alloc_init_supersection currently
      increments the phys addr by 1MB on each of the 16 iterations and then
      forces alignment to supersection size (16MB).  This is really uneeded
      b/c we have already forced the phys address to be 16MB aligned in
      create_mapping(). Furthermore, this breaks 36-bit addressing b/c bits
      [23:20] of the PMD contain bits [35:32] of the physical address and
      the masking causes us to loose those bits thus ending up with an
      incorrect virt -> phys translation.  The other option is to have an
      alloc_init_supersection36.
      Tested on Intel IXP2350 CPU with 36-bit static I/O mappings.
      Signed-off-by: NDeepak Saxena <dsaxena@plexity.net>
      Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      083bc6b3
  6. 17 8月, 2005 1 次提交
  7. 15 8月, 2005 1 次提交
  8. 10 8月, 2005 2 次提交
  9. 04 8月, 2005 2 次提交
  10. 27 7月, 2005 1 次提交
  11. 11 7月, 2005 2 次提交
  12. 07 7月, 2005 1 次提交
  13. 04 7月, 2005 1 次提交
  14. 01 7月, 2005 2 次提交
  15. 30 6月, 2005 1 次提交
  16. 28 6月, 2005 1 次提交
  17. 27 6月, 2005 2 次提交
  18. 25 6月, 2005 1 次提交
  19. 23 6月, 2005 1 次提交
  20. 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
  21. 21 6月, 2005 2 次提交
  22. 20 6月, 2005 2 次提交
  23. 09 6月, 2005 2 次提交
  24. 08 6月, 2005 1 次提交
  25. 17 5月, 2005 1 次提交
  26. 13 5月, 2005 1 次提交
  27. 11 5月, 2005 3 次提交
  28. 10 5月, 2005 1 次提交