1. 20 Oct, 2008 7 commits
  2. 27 Aug, 2008 1 commit
    • Mel Gorman's avatar
      [ARM] Skip memory holes in FLATMEM when reading /proc/pagetypeinfo · e80d6a24
      Mel Gorman authored
      Ordinarily, memory holes in flatmem still have a valid memmap and is safe
      to use. However, an architecture (ARM) frees up the memmap backing memory
      holes on the assumption it is never used. /proc/pagetypeinfo reads the
      whole range of pages in a zone believing that the memmap is valid and that
      pfn_valid will return false if it is not. On ARM, freeing the memmap breaks
      the page->zone linkages even though pfn_valid() returns true and the kernel
      can oops shortly afterwards due to accessing a bogus struct zone *.
      
      This patch lets architectures say when FLATMEM can have holes in the
      memmap. Rather than an expensive check for valid memory, /proc/pagetypeinfo
      will confirm that the page linkages are still valid by checking page->zone
      is still the expected zone. The lookup of page_zone is safe as there is a
      limited range of memory that is accessed when calling page_zone.  Even if
      page_zone happens to return the correct zone, the impact is that the counters
      in /proc/pagetypeinfo are slightly off but fragmentation monitoring is
      unlikely to be relevant on an embedded system.
      Reported-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
      Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
      Tested-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      e80d6a24
  3. 24 Jul, 2008 1 commit
  4. 23 May, 2008 1 commit
  5. 13 May, 2008 1 commit
  6. 30 Apr, 2008 2 commits
  7. 28 Apr, 2008 3 commits
  8. 16 Apr, 2008 1 commit
    • KOSAKI Motohiro's avatar
      add "Isolate" migratetype name to /proc/pagetypeinfo · 91446b06
      KOSAKI Motohiro authored
      In a5d76b54 (memory unplug: page isolation by
      KAMEZAWA Hiroyuki), "isolate" migratetype added.  but unfortunately, it
      doesn't treat /proc/pagetypeinfo display logic.
      
      this patch add "Isolate" to pagetype name field.
      
      /proc/pagetype
      before:
      ------------------------------------------------------------------------------------------------------------------------
      Free pages count per migrate type at order       0      1      2      3      4      5      6      7      8      9     10
      Node    0, zone      DMA, type    Unmovable      1      2      2      2      1      2      2      1      1      0      0
      Node    0, zone      DMA, type  Reclaimable      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone      DMA, type      Movable      2      3      3      1      3      3      2      0      0      0      0
      Node    0, zone      DMA, type      Reserve      0      0      0      0      0      0      0      0      0      0      1
      Node    0, zone      DMA, type       <NULL>      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone   Normal, type    Unmovable      1      9      7      4      1      1      1      1      0      0      0
      Node    0, zone   Normal, type  Reclaimable      5      2      0      0      1      1      0      0      0      1      0
      Node    0, zone   Normal, type      Movable      0      1      1      0      0      0      1      0      0      1     60
      Node    0, zone   Normal, type      Reserve      0      0      0      0      0      0      0      0      0      0      1
      Node    0, zone   Normal, type       <NULL>      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone  HighMem, type    Unmovable      0      0      1      1      1      0      1      1      2      2      0
      Node    0, zone  HighMem, type  Reclaimable      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone  HighMem, type      Movable    236     62      6      2      2      1      1      0      1      1     16
      Node    0, zone  HighMem, type      Reserve      0      0      0      0      0      0      0      0      0      0      1
      Node    0, zone  HighMem, type       <NULL>      0      0      0      0      0      0      0      0      0      0      0
      
      Number of blocks type     Unmovable  Reclaimable      Movable      Reserve       <NULL>
      Node 0, zone      DMA            1            0            2       1            0
      Node 0, zone   Normal           10           40          169       1            0
      Node 0, zone  HighMem            2            0          283       1            0
      
      after:
      ------------------------------------------------------------------------------------------------------------------------
      Free pages count per migrate type at order       0      1      2      3      4      5      6      7      8      9     10
      Node    0, zone      DMA, type    Unmovable      1      2      2      2      1      2      2      1      1      0      0
      Node    0, zone      DMA, type  Reclaimable      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone      DMA, type      Movable      2      3      3      1      3      3      2      0      0      0      0
      Node    0, zone      DMA, type      Reserve      0      0      0      0      0      0      0      0      0      0      1
      Node    0, zone      DMA, type      Isolate      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone   Normal, type    Unmovable      0      2      1      1      0      1      0      0      0      0      0
      Node    0, zone   Normal, type  Reclaimable      1      1      1      1      1      0      1      1      1      0      0
      Node    0, zone   Normal, type      Movable      0      1      1      1      0      1      0      1      0      0    196
      Node    0, zone   Normal, type      Reserve      0      0      0      0      0      0      0      0      0      0      1
      Node    0, zone   Normal, type      Isolate      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone  HighMem, type    Unmovable      0      1      0      0      0      1      1      1      2      2      0
      Node    0, zone  HighMem, type  Reclaimable      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone  HighMem, type      Movable      1      0      1      1      0      0      0      0      1      0    200
      Node    0, zone  HighMem, type      Reserve      0      0      0      0      0      0      0      0      0      0      1
      Node    0, zone  HighMem, type      Isolate      0      0      0      0      0      0      0      0      0      0      0
      
      Number of blocks type     Unmovable  Reclaimable      Movable      Reserve      Isolate
      Node 0, zone      DMA            1            0            2       1            0
      Node 0, zone   Normal            8            4          207       1            0
      Node 0, zone  HighMem            2            0          283       1            0
      Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Acked-by: default avatarMel Gorman <mel@csn.ul.ie>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      91446b06
  9. 05 Feb, 2008 3 commits
  10. 15 Nov, 2007 1 commit
  11. 17 Oct, 2007 1 commit
    • David Rientjes's avatar
      oom: change all_unreclaimable zone member to flags · e815af95
      David Rientjes authored
      Convert the int all_unreclaimable member of struct zone to unsigned long
      flags.  This can now be used to specify several different zone flags such as
      all_unreclaimable and reclaim_in_progress, which can now be removed and
      converted to a per-zone flag.
      
      Flags are set and cleared as follows:
      
      	zone_set_flag(struct zone *zone, zone_flags_t flag)
      	zone_clear_flag(struct zone *zone, zone_flags_t flag)
      
      Defines the first zone flags, ZONE_ALL_UNRECLAIMABLE and ZONE_RECLAIM_LOCKED,
      which have the same semantics as the old zone->all_unreclaimable and
      zone->reclaim_in_progress, respectively.  Also converts all current users that
      set or clear either flag to use the new interface.
      
      Helper functions are defined to test the flags:
      
      	int zone_is_all_unreclaimable(const struct zone *zone)
      	int zone_is_reclaim_locked(const struct zone *zone)
      
      All flag operators are of the atomic variety because there are currently
      readers that are implemented that do not take zone->lock.
      
      [akpm@linux-foundation.org: add needed include]
      Cc: Andrea Arcangeli <andrea@suse.de>
      Acked-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e815af95
  12. 16 Oct, 2007 2 commits
    • Adrian Bunk's avatar
      mm/vmstat.c: cleanups · e2fc88d0
      Adrian Bunk authored
      This patch contains the following cleanups:
      - make the needlessly global setup_vmstat() static
      - remove the unused refresh_vm_stats()
      Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
      Acked-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e2fc88d0
    • Mel Gorman's avatar
      Print out statistics in relation to fragmentation avoidance to /proc/pagetypeinfo · 467c996c
      Mel Gorman authored
      This patch provides fragmentation avoidance statistics via /proc/pagetypeinfo.
       The information is collected only on request so there is no runtime overhead.
       The statistics are in three parts:
      
      The first part prints information on the size of blocks that pages are
      being grouped on and looks like
      
      Page block order: 10
      Pages per block:  1024
      
      The second part is a more detailed version of /proc/buddyinfo and looks like
      
      Free pages count per migrate type at order       0      1      2      3      4      5      6      7      8      9     10
      Node    0, zone      DMA, type    Unmovable      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone      DMA, type  Reclaimable      1      0      0      0      0      0      0      0      0      0      0
      Node    0, zone      DMA, type      Movable      0      0      0      0      0      0      0      0      0      0      0
      Node    0, zone      DMA, type      Reserve      0      4      4      0      0      0      0      1      0      1      0
      Node    0, zone   Normal, type    Unmovable    111      8      4      4      2      3      1      0      0      0      0
      Node    0, zone   Normal, type  Reclaimable    293     89      8      0      0      0      0      0      0      0      0
      Node    0, zone   Normal, type      Movable      1      6     13      9      7      6      3      0      0      0      0
      Node    0, zone   Normal, type      Reserve      0      0      0      0      0      0      0      0      0      0      4
      
      The third part looks like
      
      Number of blocks type     Unmovable  Reclaimable      Movable      Reserve
      Node 0, zone      DMA            0            1            2            1
      Node 0, zone   Normal            3           17           94            4
      
      To walk the zones within a node with interrupts disabled, walk_zones_in_node()
      is introduced and shared between /proc/buddyinfo, /proc/zoneinfo and
      /proc/pagetypeinfo to reduce code duplication.  It seems specific to what
      vmstat.c requires but could be broken out as a general utility function in
      mmzone.c if there were other other potential users.
      Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
      Acked-by: default avatarAndy Whitcroft <apw@shadowen.org>
      Acked-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      467c996c
  13. 30 Jul, 2007 1 commit
    • Alexey Dobriyan's avatar
      Remove fs.h from mm.h · 4e950f6f
      Alexey Dobriyan authored
      Remove fs.h from mm.h. For this,
       1) Uninline vma_wants_writenotify(). It's pretty huge anyway.
       2) Add back fs.h or less bloated headers (err.h) to files that need it.
      
      As result, on x86_64 allyesconfig, fs.h dependencies cut down from 3929 files
      rebuilt down to 3444 (-12.3%).
      
      Cross-compile tested without regressions on my two usual configs and (sigh):
      
      alpha              arm-mx1ads        mips-bigsur          powerpc-ebony
      alpha-allnoconfig  arm-neponset      mips-capcella        powerpc-g5
      alpha-defconfig    arm-netwinder     mips-cobalt          powerpc-holly
      alpha-up           arm-netx          mips-db1000          powerpc-iseries
      arm                arm-ns9xxx        mips-db1100          powerpc-linkstation
      arm-assabet        arm-omap_h2_1610  mips-db1200          powerpc-lite5200
      arm-at91rm9200dk   arm-onearm        mips-db1500          powerpc-maple
      arm-at91rm9200ek   arm-picotux200    mips-db1550          powerpc-mpc7448_hpc2
      arm-at91sam9260ek  arm-pleb          mips-ddb5477         powerpc-mpc8272_ads
      arm-at91sam9261ek  arm-pnx4008       mips-decstation      powerpc-mpc8313_rdb
      arm-at91sam9263ek  arm-pxa255-idp    mips-e55             powerpc-mpc832x_mds
      arm-at91sam9rlek   arm-realview      mips-emma2rh         powerpc-mpc832x_rdb
      arm-ateb9200       arm-realview-smp  mips-excite          powerpc-mpc834x_itx
      arm-badge4         arm-rpc           mips-fulong          powerpc-mpc834x_itxgp
      arm-carmeva        arm-s3c2410       mips-ip22            powerpc-mpc834x_mds
      arm-cerfcube       arm-shannon       mips-ip27            powerpc-mpc836x_mds
      arm-clps7500       arm-shark         mips-ip32            powerpc-mpc8540_ads
      arm-collie         arm-simpad        mips-jazz            powerpc-mpc8544_ds
      arm-corgi          arm-spitz         mips-jmr3927         powerpc-mpc8560_ads
      arm-csb337         arm-trizeps4      mips-malta           powerpc-mpc8568mds
      arm-csb637         arm-versatile     mips-mipssim         powerpc-mpc85xx_cds
      arm-ebsa110        i386              mips-mpc30x          powerpc-mpc8641_hpcn
      arm-edb7211        i386-allnoconfig  mips-msp71xx         powerpc-mpc866_ads
      arm-em_x270        i386-defconfig    mips-ocelot          powerpc-mpc885_ads
      arm-ep93xx         i386-up           mips-pb1100          powerpc-pasemi
      arm-footbridge     ia64              mips-pb1500          powerpc-pmac32
      arm-fortunet       ia64-allnoconfig  mips-pb1550          powerpc-ppc64
      arm-h3600          ia64-bigsur       mips-pnx8550-jbs     powerpc-prpmc2800
      arm-h7201          ia64-defconfig    mips-pnx8550-stb810  powerpc-ps3
      arm-h7202          ia64-gensparse    mips-qemu            powerpc-pseries
      arm-hackkit        ia64-sim          mips-rbhma4200       powerpc-up
      arm-integrator     ia64-sn2          mips-rbhma4500       s390
      arm-iop13xx        ia64-tiger        mips-rm200           s390-allnoconfig
      arm-iop32x         ia64-up           mips-sb1250-swarm    s390-defconfig
      arm-iop33x         ia64-zx1          mips-sead            s390-up
      arm-ixp2000        m68k              mips-tb0219          sparc
      arm-ixp23xx        m68k-amiga        mips-tb0226          sparc-allnoconfig
      arm-ixp4xx         m68k-apollo       mips-tb0287          sparc-defconfig
      arm-jornada720     m68k-atari        mips-workpad         sparc-up
      arm-kafa           m68k-bvme6000     mips-wrppmc          sparc64
      arm-kb9202         m68k-hp300        mips-yosemite        sparc64-allnoconfig
      arm-ks8695         m68k-mac          parisc               sparc64-defconfig
      arm-lart           m68k-mvme147      parisc-allnoconfig   sparc64-up
      arm-lpd270         m68k-mvme16x      parisc-defconfig     um-x86_64
      arm-lpd7a400       m68k-q40          parisc-up            x86_64
      arm-lpd7a404       m68k-sun3         powerpc              x86_64-allnoconfig
      arm-lubbock        m68k-sun3x        powerpc-cell         x86_64-defconfig
      arm-lusl7200       mips              powerpc-celleb       x86_64-up
      arm-mainstone      mips-atlas        powerpc-chrp32
      Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4e950f6f
  14. 17 Jul, 2007 1 commit
    • Mel Gorman's avatar
      Create the ZONE_MOVABLE zone · 2a1e274a
      Mel Gorman authored
      The following 8 patches against 2.6.20-mm2 create a zone called ZONE_MOVABLE
      that is only usable by allocations that specify both __GFP_HIGHMEM and
      __GFP_MOVABLE.  This has the effect of keeping all non-movable pages within a
      single memory partition while allowing movable allocations to be satisfied
      from either partition.  The patches may be applied with the list-based
      anti-fragmentation patches that groups pages together based on mobility.
      
      The size of the zone is determined by a kernelcore= parameter specified at
      boot-time.  This specifies how much memory is usable by non-movable
      allocations and the remainder is used for ZONE_MOVABLE.  Any range of pages
      within ZONE_MOVABLE can be released by migrating the pages or by reclaiming.
      
      When selecting a zone to take pages from for ZONE_MOVABLE, there are two
      things to consider.  First, only memory from the highest populated zone is
      used for ZONE_MOVABLE.  On the x86, this is probably going to be ZONE_HIGHMEM
      but it would be ZONE_DMA on ppc64 or possibly ZONE_DMA32 on x86_64.  Second,
      the amount of memory usable by the kernel will be spread evenly throughout
      NUMA nodes where possible.  If the nodes are not of equal size, the amount of
      memory usable by the kernel on some nodes may be greater than others.
      
      By default, the zone is not as useful for hugetlb allocations because they are
      pinned and non-migratable (currently at least).  A sysctl is provided that
      allows huge pages to be allocated from that zone.  This means that the huge
      page pool can be resized to the size of ZONE_MOVABLE during the lifetime of
      the system assuming that pages are not mlocked.  Despite huge pages being
      non-movable, we do not introduce additional external fragmentation of note as
      huge pages are always the largest contiguous block we care about.
      
      Credit goes to Andy Whitcroft for catching a large variety of problems during
      review of the patches.
      
      This patch creates an additional zone, ZONE_MOVABLE.  This zone is only usable
      by allocations which specify both __GFP_HIGHMEM and __GFP_MOVABLE.  Hot-added
      memory continues to be placed in their existing destination as there is no
      mechanism to redirect them to a specific zone.
      
      [y-goto@jp.fujitsu.com: Fix section mismatch of memory hotplug related code]
      [akpm@linux-foundation.org: various fixes]
      Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Signed-off-by: default avatarYasunori Goto <y-goto@jp.fujitsu.com>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2a1e274a
  15. 06 Jul, 2007 1 commit
  16. 21 May, 2007 1 commit
    • Alexey Dobriyan's avatar
      Detach sched.h from mm.h · e8edc6e0
      Alexey Dobriyan authored
      First thing mm.h does is including sched.h solely for can_do_mlock() inline
      function which has "current" dereference inside. By dealing with can_do_mlock()
      mm.h can be detached from sched.h which is good. See below, why.
      
      This patch
      a) removes unconditional inclusion of sched.h from mm.h
      b) makes can_do_mlock() normal function in mm/mlock.c
      c) exports can_do_mlock() to not break compilation
      d) adds sched.h inclusions back to files that were getting it indirectly.
      e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
         getting them indirectly
      
      Net result is:
      a) mm.h users would get less code to open, read, preprocess, parse, ... if
         they don't need sched.h
      b) sched.h stops being dependency for significant number of files:
         on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
         after patch it's only 3744 (-8.3%).
      
      Cross-compile tested on
      
      	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
      	alpha alpha-up
      	arm
      	i386 i386-up i386-defconfig i386-allnoconfig
      	ia64 ia64-up
      	m68k
      	mips
      	parisc parisc-up
      	powerpc powerpc-up
      	s390 s390-up
      	sparc sparc-up
      	sparc64 sparc64-up
      	um-x86_64
      	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig
      
      as well as my two usual configs.
      Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e8edc6e0
  17. 11 May, 2007 1 commit
    • Christoph Lameter's avatar
      VM statistics: Make timer deferrable · 39bf6270
      Christoph Lameter authored
      VM statistics updates do not matter if the kernel is in idle powersaving
      mode.  So allow the timer to be deferred.
      
      It would be better though if we could switch the timer between deferrable
      and nondeferrable based on differentials present.  The timer would start
      out nondeferrable and if we find that there were no updates in the last
      statistics interval then we would switch the timer to deferrable.  If the
      timer later finds again that there are differentials then go to
      nondeferrable again.
      
      And yet another way would be to run the timer shortly before going to idle?
      
      The solution here means that the VM counters may be slightly off during
      idle since differentials may be still pending while the timer is deferred.
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      39bf6270
  18. 09 May, 2007 4 commits
    • Christoph Lameter's avatar
      Move remote node draining out of slab allocators · 4037d452
      Christoph Lameter authored
      Currently the slab allocators contain callbacks into the page allocator to
      perform the draining of pagesets on remote nodes.  This requires SLUB to have
      a whole subsystem in order to be compatible with SLAB.  Moving node draining
      out of the slab allocators avoids a section of code in SLUB.
      
      Move the node draining so that is is done when the vm statistics are updated.
      At that point we are already touching all the cachelines with the pagesets of
      a processor.
      
      Add a expire counter there.  If we have to update per zone or global vm
      statistics then assume that the pageset will require subsequent draining.
      
      The expire counter will be decremented on each vm stats update pass until it
      reaches zero.  Then we will drain one batch from the pageset.  The draining
      will cause vm counter updates which will then cause another expiration until
      the pcp is empty.  So we will drain a batch every 3 seconds.
      
      Note that remote node draining is a somewhat esoteric feature that is required
      on large NUMA systems because otherwise significant portions of system memory
      can become trapped in pcp queues.  The number of pcp is determined by the
      number of processors and nodes in a system.  A system with 4 processors and 2
      nodes has 8 pcps which is okay.  But a system with 1024 processors and 512
      nodes has 512k pcps with a high potential for large amount of memory being
      caught in them.
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4037d452
    • Christoph Lameter's avatar
      Make vm statistics update interval configurable · 77461ab3
      Christoph Lameter authored
      Make it configurable.  Code in mm makes the vm statistics intervals
      independent from the cache reaper use that opportunity to make it
      configurable.
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      77461ab3
    • Christoph Lameter's avatar
      vmstat: use our own timer events · d1187ed2
      Christoph Lameter authored
      vmstat is currently using the cache reaper to periodically bring the
      statistics up to date.  The cache reaper does only exists in SLUB as a way to
      provide compatibility with SLAB.  This patch removes the vmstat calls from the
      slab allocators and provides its own handling.
      
      The advantage is also that we can use a different frequency for the updates.
      Refreshing vm stats is a pretty fast job so we can run this every second and
      stagger this by only one tick.  This will lead to some overlap in large
      systems.  F.e a system running at 250 HZ with 1024 processors will have 4 vm
      updates occurring at once.
      
      However, the vm stats update only accesses per node information.  It is only
      necessary to stagger the vm statistics updates per processor in each node.  Vm
      counter updates occurring on distant nodes will not cause cacheline
      contention.
      
      We could implement an alternate approach that runs the first processor on each
      node at the second and then each of the other processor on a node on a
      subsequent tick.  That may be useful to keep a large amount of the second free
      of timer activity.  Maybe the timer folks will have some feedback on this one?
      
      [jirislaby@gmail.com: add missing break]
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarJiri Slaby <jirislaby@gmail.com>
      Cc: Oleg Nesterov <oleg@tv-sign.ru>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d1187ed2
    • Rafael J. Wysocki's avatar
      Add suspend-related notifications for CPU hotplug · 8bb78442
      Rafael J. Wysocki authored
      Since nonboot CPUs are now disabled after tasks and devices have been
      frozen and the CPU hotplug infrastructure is used for this purpose, we need
      special CPU hotplug notifications that will help the CPU-hotplug-aware
      subsystems distinguish normal CPU hotplug events from CPU hotplug events
      related to a system-wide suspend or resume operation in progress.  This
      patch introduces such notifications and causes them to be used during
      suspend and resume transitions.  It also changes all of the
      CPU-hotplug-aware subsystems to take these notifications into consideration
      (for now they are handled in the same way as the corresponding "normal"
      ones).
      
      [oleg@tv-sign.ru: cleanups]
      Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
      Cc: Gautham R Shenoy <ego@in.ibm.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8bb78442
  19. 11 Feb, 2007 7 commits