1. 24 6月, 2005 10 次提交
  2. 22 6月, 2005 3 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
    • I
      [PATCH] smp_processor_id() cleanup · 39c715b7
      Ingo Molnar 提交于
      This patch implements a number of smp_processor_id() cleanup ideas that
      Arjan van de Ven and I came up with.
      
      The previous __smp_processor_id/_smp_processor_id/smp_processor_id API
      spaghetti was hard to follow both on the implementational and on the
      usage side.
      
      Some of the complexity arose from picking wrong names, some of the
      complexity comes from the fact that not all architectures defined
      __smp_processor_id.
      
      In the new code, there are two externally visible symbols:
      
       - smp_processor_id(): debug variant.
      
       - raw_smp_processor_id(): nondebug variant. Replaces all existing
         uses of _smp_processor_id() and __smp_processor_id(). Defined
         by every SMP architecture in include/asm-*/smp.h.
      
      There is one new internal symbol, dependent on DEBUG_PREEMPT:
      
       - debug_smp_processor_id(): internal debug variant, mapped to
                                   smp_processor_id().
      
      Also, i moved debug_smp_processor_id() from lib/kernel_lock.c into a new
      lib/smp_processor_id.c file.  All related comments got updated and/or
      clarified.
      
      I have build/boot tested the following 8 .config combinations on x86:
      
       {SMP,UP} x {PREEMPT,!PREEMPT} x {DEBUG_PREEMPT,!DEBUG_PREEMPT}
      
      I have also build/boot tested x64 on UP/PREEMPT/DEBUG_PREEMPT.  (Other
      architectures are untested, but should work just fine.)
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      Signed-off-by: NArjan van de Ven <arjan@infradead.org>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      39c715b7
    • S
      [PATCH] x86_64: TASK_SIZE fixes for compatibility mode processes · 84929801
      Suresh Siddha 提交于
      Appended patch will setup compatibility mode TASK_SIZE properly.  This will
      fix atleast three known bugs that can be encountered while running
      compatibility mode apps.
      
      a) A malicious 32bit app can have an elf section at 0xffffe000.  During
         exec of this app, we will have a memory leak as insert_vm_struct() is
         not checking for return value in syscall32_setup_pages() and thus not
         freeing the vma allocated for the vsyscall page.  And instead of exec
         failing (as it has addresses > TASK_SIZE), we were allowing it to
         succeed previously.
      
      b) With a 32bit app, hugetlb_get_unmapped_area/arch_get_unmapped_area
         may return addresses beyond 32bits, ultimately causing corruption
         because of wrap-around and resulting in SEGFAULT, instead of returning
         ENOMEM.
      
      c) 32bit app doing this below mmap will now fail.
      
        mmap((void *)(0xFFFFE000UL), 0x10000UL, PROT_READ|PROT_WRITE,
      	MAP_FIXED|MAP_PRIVATE|MAP_ANON, 0, 0);
      Signed-off-by: NZou Nan hai <nanhai.zou@intel.com>
      Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
      Cc: Andi Kleen <ak@muc.de>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      84929801
  3. 09 6月, 2005 1 次提交
  4. 01 6月, 2005 2 次提交
  5. 29 5月, 2005 1 次提交
  6. 27 5月, 2005 1 次提交
    • A
      [PATCH] Note on ACPI build fix · 8aadff7d
      Alexander Nyberg 提交于
      Even after the previous fix you can still set CONFIG_ACPI_BOOT
      indirectly even without CONFIG_ACPI by choosing CONFIG_PCI and
      CONFIG_PCI_MMCONFIG.
      
      That doesn't build very well either.
      
      This makes PCI_MMCONFIG depend on ACPI, fixing that hole.
      
      [ I guess in theory Kconfig could follow the whole chain of dependencies
        for things that get selected, but that sounds insanely complicated, so
        we'll just fix up these things by hand.  --Linus ]
      Signed-off-by: NAlexander Nyberg <alexn@telia.com>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      8aadff7d
  7. 26 5月, 2005 1 次提交
  8. 21 5月, 2005 6 次提交
  9. 17 5月, 2005 15 次提交
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