1. 22 Jun, 2005 18 commits
    • Wolfgang Wander's avatar
      [PATCH] Avoiding mmap fragmentation · 1363c3cd
      Wolfgang Wander authored
      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: default avatarWolfgang Wander <wwc@rentec.com>
      Credit-to: "Richard Purdie" <rpurdie@rpsys.net>
      Signed-off-by: default avatarKen Chen <kenneth.w.chen@intel.com>
      Acked-by: Ingo Molnar <mingo@elte.hu> (partly)
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      1363c3cd
    • Christoph Lameter's avatar
      [PATCH] node local per-cpu-pages · e7c8d5c9
      Christoph Lameter authored
      This patch modifies the way pagesets in struct zone are managed.
      
      Each zone has a per-cpu array of pagesets.  So any particular CPU has some
      memory in each zone structure which belongs to itself.  Even if that CPU is
      not local to that zone.
      
      So the patch relocates the pagesets for each cpu to the node that is nearest
      to the cpu instead of allocating the pagesets in the (possibly remote) target
      zone.  This means that the operations to manage pages on remote zone can be
      done with information available locally.
      
      We play a macro trick so that non-NUMA pmachines avoid the additional
      pointer chase on the page allocator fastpath.
      
      AIM7 benchmark on a 32 CPU SGI Altix
      
      w/o patches:
      Tasks    jobs/min  jti  jobs/min/task      real       cpu
          1      484.68  100       484.6769     12.01      1.97   Fri Mar 25 11:01:42 2005
        100    27140.46   89       271.4046     21.44    148.71   Fri Mar 25 11:02:04 2005
        200    30792.02   82       153.9601     37.80    296.72   Fri Mar 25 11:02:42 2005
        300    32209.27   81       107.3642     54.21    451.34   Fri Mar 25 11:03:37 2005
        400    34962.83   78        87.4071     66.59    588.97   Fri Mar 25 11:04:44 2005
        500    31676.92   75        63.3538     91.87    742.71   Fri Mar 25 11:06:16 2005
        600    36032.69   73        60.0545     96.91    885.44   Fri Mar 25 11:07:54 2005
        700    35540.43   77        50.7720    114.63   1024.28   Fri Mar 25 11:09:49 2005
        800    33906.70   74        42.3834    137.32   1181.65   Fri Mar 25 11:12:06 2005
        900    34120.67   73        37.9119    153.51   1325.26   Fri Mar 25 11:14:41 2005
       1000    34802.37   74        34.8024    167.23   1465.26   Fri Mar 25 11:17:28 2005
      
      with slab API changes and pageset patch:
      
      Tasks    jobs/min  jti  jobs/min/task      real       cpu
          1      485.00  100       485.0000     12.00      1.96   Fri Mar 25 11:46:18 2005
        100    28000.96   89       280.0096     20.79    150.45   Fri Mar 25 11:46:39 2005
        200    32285.80   79       161.4290     36.05    293.37   Fri Mar 25 11:47:16 2005
        300    40424.15   84       134.7472     43.19    438.42   Fri Mar 25 11:47:59 2005
        400    39155.01   79        97.8875     59.46    590.05   Fri Mar 25 11:48:59 2005
        500    37881.25   82        75.7625     76.82    730.19   Fri Mar 25 11:50:16 2005
        600    39083.14   78        65.1386     89.35    872.79   Fri Mar 25 11:51:46 2005
        700    38627.83   77        55.1826    105.47   1022.46   Fri Mar 25 11:53:32 2005
        800    39631.94   78        49.5399    117.48   1169.94   Fri Mar 25 11:55:30 2005
        900    36903.70   79        41.0041    141.94   1310.78   Fri Mar 25 11:57:53 2005
       1000    36201.23   77        36.2012    160.77   1458.31   Fri Mar 25 12:00:34 2005
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarShobhit Dayal <shobhit@calsoftinc.com>
      Signed-off-by: default avatarShai Fultheim <Shai@Scalex86.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      e7c8d5c9
    • David Gibson's avatar
      [PATCH] Hugepage consolidation · 63551ae0
      David Gibson authored
      A lot of the code in arch/*/mm/hugetlbpage.c is quite similar.  This patch
      attempts to consolidate a lot of the code across the arch's, putting the
      combined version in mm/hugetlb.c.  There are a couple of uglyish hacks in
      order to covert all the hugepage archs, but the result is a very large
      reduction in the total amount of code.  It also means things like hugepage
      lazy allocation could be implemented in one place, instead of six.
      
      Tested, at least a little, on ppc64, i386 and x86_64.
      
      Notes:
      	- this patch changes the meaning of set_huge_pte() to be more
      	  analagous to set_pte()
      	- does SH4 need s special huge_ptep_get_and_clear()??
      Acked-by: default avatarWilliam Lee Irwin <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      63551ae0
    • Martin Hicks's avatar
      [PATCH] VM: rate limit early reclaim · 1e7e5a90
      Martin Hicks authored
      When early zone reclaim is turned on the LRU is scanned more frequently when a
      zone is low on memory.  This limits when the zone reclaim can be called by
      skipping the scan if another thread (either via kswapd or sync reclaim) is
      already reclaiming from the zone.
      Signed-off-by: default avatarMartin Hicks <mort@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      1e7e5a90
    • Martin Hicks's avatar
      [PATCH] VM: add __GFP_NORECLAIM · 0c35bbad
      Martin Hicks authored
      When using the early zone reclaim, it was noticed that allocating new pages
      that should be spread across the whole system caused eviction of local pages.
      
      This adds a new GFP flag to prevent early reclaim from happening during
      certain allocation attempts.  The example that is implemented here is for page
      cache pages.  We want page cache pages to be spread across the whole system,
      and we don't want page cache pages to evict other pages to get local memory.
      Signed-off-by: default avatarMartin Hicks <mort@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      0c35bbad
    • Martin Hicks's avatar
      [PATCH] VM: early zone reclaim · 753ee728
      Martin Hicks authored
      This is the core of the (much simplified) early reclaim.  The goal of this
      patch is to reclaim some easily-freed pages from a zone before falling back
      onto another zone.
      
      One of the major uses of this is NUMA machines.  With the default allocator
      behavior the allocator would look for memory in another zone, which might be
      off-node, before trying to reclaim from the current zone.
      
      This adds a zone tuneable to enable early zone reclaim.  It is selected on a
      per-zone basis and is turned on/off via syscall.
      
      Adding some extra throttling on the reclaim was also required (patch
      4/4).  Without the machine would grind to a crawl when doing a "make -j"
      kernel build.  Even with this patch the System Time is higher on
      average, but it seems tolerable.  Here are some numbers for kernbench
      runs on a 2-node, 4cpu, 8Gig RAM Altix in the "make -j" run:
      
      			wall  user   sys   %cpu  ctx sw.  sleeps
      			----  ----   ---   ----   ------  ------
      No patch		1009  1384   847   258   298170   504402
      w/patch, no reclaim     880   1376   667   288   254064   396745
      w/patch & reclaim       1079  1385   926   252   291625   548873
      
      These numbers are the average of 2 runs of 3 "make -j" runs done right
      after system boot.  Run-to-run variability for "make -j" is huge, so
      these numbers aren't terribly useful except to seee that with reclaim
      the benchmark still finishes in a reasonable amount of time.
      
      I also looked at the NUMA hit/miss stats for the "make -j" runs and the
      reclaim doesn't make any difference when the machine is thrashing away.
      
      Doing a "make -j8" on a single node that is filled with page cache pages
      takes 700 seconds with reclaim turned on and 735 seconds without reclaim
      (due to remote memory accesses).
      
      The simple zone_reclaim syscall program is at
      http://www.bork.org/~mort/sgi/zone_reclaim.cSigned-off-by: default avatarMartin Hicks <mort@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      753ee728
    • Martin Hicks's avatar
      [PATCH] VM: add may_swap flag to scan_control · bfbb38fb
      Martin Hicks authored
      Here's the next round of these patches.  These are totally different in
      an attempt to meet the "simpler" request after the last patches.  For
      reference the earlier threads are:
      
      http://marc.theaimsgroup.com/?l=linux-kernel&m=110839604924587&w=2
      http://marc.theaimsgroup.com/?l=linux-mm&m=111461480721249&w=2
      
      This set of patches replaces my other vm- patches that are currently in
      -mm.  So they're against 2.6.12-rc5-mm1 about half way through the -mm
      patchset.
      
      As I said already this patch is a lot simpler.  The reclaim is turned on
      or off on a per-zone basis using a syscall.  I haven't tested the x86
      syscall, so it might be wrong.  It uses the existing reclaim/pageout
      code with the small addition of a may_swap flag to scan_control
      (patch 1/4).
      
      I also added __GFP_NORECLAIM (patch 3/4) so that certain allocation
      types can be flagged to never cause reclaim.  This was a deficiency
      that was in all of my earlier patch sets.  Previously, doing a big
      buffered read would fill one zone with page cache and then start to
      reclaim from that same zone, leaving the other zones untouched.
      
      Adding some extra throttling on the reclaim was also required (patch
      4/4).  Without the machine would grind to a crawl when doing a "make -j"
      kernel build.  Even with this patch the System Time is higher on
      average, but it seems tolerable.  Here are some numbers for kernbench
      runs on a 2-node, 4cpu, 8Gig RAM Altix in the "make -j" run:
      
      			wall  user   sys   %cpu  ctx sw.  sleeps
      			----  ----   ---   ----   ------  ------
      No patch		1009  1384   847   258   298170   504402
      w/patch, no reclaim     880   1376   667   288   254064   396745
      w/patch & reclaim       1079  1385   926   252   291625   548873
      
      These numbers are the average of 2 runs of 3 "make -j" runs done right
      after system boot.  Run-to-run variability for "make -j" is huge, so
      these numbers aren't terribly useful except to seee that with reclaim
      the benchmark still finishes in a reasonable amount of time.
      
      I also looked at the NUMA hit/miss stats for the "make -j" runs and the
      reclaim doesn't make any difference when the machine is thrashing away.
      
      Doing a "make -j8" on a single node that is filled with page cache pages
      takes 700 seconds with reclaim turned on and 735 seconds without reclaim
      (due to remote memory accesses).
      
      The simple zone_reclaim syscall program is at
      http://www.bork.org/~mort/sgi/zone_reclaim.c
      
      This patch:
      
      This adds an extra switch to the scan_control struct.  It simply lets the
      reclaim code know if its allowed to swap pages out.
      
      This was required for a simple per-zone reclaimer.  Without this addition
      pages would be swapped out as soon as a zone ran out of memory and the early
      reclaim kicked in.
      Signed-off-by: default avatarMartin Hicks <mort@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      bfbb38fb
    • Nikita Danilov's avatar
      [PATCH] mm: add /proc/zoneinfo · 295ab934
      Nikita Danilov authored
      Add /proc/zoneinfo file to display information about memory zones.  Useful
      to analyze VM behaviour.
      Signed-off-by: default avatarNikita Danilov <nikita@clusterfs.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      295ab934
    • Prasanna Meda's avatar
      [PATCH] madvise: merge the maps · 05b74384
      Prasanna Meda authored
      This attempts to merge back the split maps.  This code is mostly copied
      from Chrisw's mlock merging from post 2.6.11 trees.  The only difference is
      in munmapped_error handling.  Also passed prev to willneed/dontneed,
      eventhogh they do not handle it now, since I felt it will be cleaner,
      instead of handling prev in madvise_vma in some cases and in subfunction in
      some cases.
      Signed-off-by: default avatarPrasanna Meda <pmeda@akamai.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      05b74384
    • Prasanna Meda's avatar
      [PATCH] madvise: do not split the maps · e798c6e8
      Prasanna Meda authored
      This attempts to avoid splittings when it is not needed, that is when
      vm_flags are same as new flags.  The idea is from the <2.6.11 mlock_fixup
      and others.  This will provide base for the next madvise merging patch.
      Signed-off-by: default avatarPrasanna Meda <pmeda@akamai.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      e798c6e8
    • akpm@osdl.org's avatar
      [PATCH] vmscan: notice slab shrinking · b15e0905
      akpm@osdl.org authored
      Fix a problem identified by Andrea Arcangeli <andrea@suse.de>
      
      kswapd will set a zone into all_unreclaimable state if it sees that we're not
      successfully reclaiming LRU pages.  But that fails to notice that we're
      successfully reclaiming slab obects, so we can set all_unreclaimable too soon.
      
      So change shrink_slab() to return a success indication if it actually
      reclaimed some objects, and don't assume that the zone is all_unreclaimable if
      that is true.  This means that we won't enter all_unreclaimable state if we
      are successfully freeing slab objects but we're not yet actually freeing slab
      pages, due to internal fragmentation.
      
      (hm, this has a shortcoming.  We could be successfully freeing ZONE_NORMAL
      slab objects while being really oom on ZONE_DMA.  If that happens then kswapd
      might burn a lot of CPU.  But given that there might be some slab objects in
      ZONE_DMA, perhaps that is appropriate.)
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      b15e0905
    • Ingo Molnar's avatar
      [PATCH] smp_processor_id() cleanup · 39c715b7
      Ingo Molnar authored
      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: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarArjan van de Ven <arjan@infradead.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      39c715b7
    • Suresh Siddha's avatar
      [PATCH] x86_64: TASK_SIZE fixes for compatibility mode processes · 84929801
      Suresh Siddha authored
      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: default avatarZou Nan hai <nanhai.zou@intel.com>
      Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
      Cc: Andi Kleen <ak@muc.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      84929801
    • Zaur Kambarov's avatar
      [PATCH] coverity: idr_get_new_above_int() overrun fix · 589777ea
      Zaur Kambarov authored
      This patch fixes overrun of array pa:
      92   		struct idr_layer *pa[MAX_LEVEL];
      
      in
      
      98   		l = idp->layers;
      99   		pa[l--] = NULL;
      
      by passing idp->layers, set in
      202  		idp->layers = layers;
      to function  sub_alloc in
      203  		v = sub_alloc(idp, ptr, &id);
      Signed-off-by: default avatarZaur Kambarov <zkambarov@coverity.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      589777ea
    • Zaur Kambarov's avatar
      [PATCH] coverity: ipmi: avoid overrun of ipmi_interfaces[] · 3a845099
      Zaur Kambarov authored
      Fix overrun of static array "ipmi_interfaces" of size 4 at position 4 with
      index variable "if_num".
      
      Definitions involved:
      297  	#define MAX_IPMI_INTERFACES 4
      298  	static ipmi_smi_t ipmi_interfaces[MAX_IPMI_INTERFACES];
      Signed-off-by: default avatarZaur Kambarov <zkambarov@coverity.com>
      Cc: Corey Minyard <minyard@acm.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      3a845099
    • bobl's avatar
      [PATCH] megaraid build fix · 7f20b6a4
      bobl authored
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      7f20b6a4
    • Andrew Morton's avatar
      [PATCH] arm: irqs_disabled() type fix · 9a558cb4
      Andrew Morton authored
      kernel/sched.c: In function `__might_sleep':
      kernel/sched.c:5461: warning: int format, long unsigned int arg (arg 3)
      
      We expect irqs_disabled() to return an int (poor man's bool).
      Acked-by: default avatarRussell King <rmk@arm.linux.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      9a558cb4
    • Linus Torvalds's avatar
  2. 21 Jun, 2005 19 commits
  3. 20 Jun, 2005 3 commits