)]}'
{
  "log": [
    {
      "commit": "fb0e7942bdcbbd2f90e61cb4cfa4fa892a873f8a",
      "tree": "71344e9afafbd631f4ac010bc8c48e0b16737299",
      "parents": [
        "2f1b6248682f8b39ca3c7e549dfc216d26c4109b"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Mon Sep 25 23:31:13 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Tue Sep 26 08:48:46 2006 -0700"
      },
      "message": "[PATCH] reduce MAX_NR_ZONES: make ZONE_DMA32 optional\n\nMake ZONE_DMA32 optional\n\n- Add #ifdefs around ZONE_DMA32 specific code and definitions.\n\n- Add CONFIG_ZONE_DMA32 config option and use that for x86_64\n  that alone needs this zone.\n\n- Remove the use of CONFIG_DMA_IS_DMA32 and CONFIG_DMA_IS_NORMAL\n  for ia64 and fix up the way per node ZVCs are calculated.\n\n- Fall back to prior GFP_ZONEMASK of 0x03 if there is no\n  DMA32 zone.\n\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "38cbcdc0a7be69a15462dc49512d43353f34b43b",
      "tree": "ca036409ffc9c027dce64281b55ad1ef973c4f14",
      "parents": [
        "9f59ce5d0e0dd837853385927b150f5cef3a7f52"
      ],
      "author": {
        "name": "Jan Blunck",
        "email": "jblunck@suse.de",
        "time": "Sat Aug 05 12:14:14 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Sun Aug 06 08:57:47 2006 -0700"
      },
      "message": "[PATCH] fix vmstat per cpu usage\n\nThe per cpu variables are used incorrectly in vmstat.h.\n\nSigned-off-by: Jan Blunck \u003cjblunck@suse.de\u003e\nCc: Christoph Lameter \u003cclameter@engr.sgi.com\u003e\nAcked-by: Steve Fox \u003cdrfickle@us.ibm.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "7f4599e9cd6bca0efc1000359584d1cff68f9f13",
      "tree": "63a02f7d0574d8bab3ec96657ae30985fcbb88e3",
      "parents": [
        "06a9ec291b3aec9c7e36af0a10ad2b556bd7e84f"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Mon Jul 10 04:44:30 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Mon Jul 10 13:24:18 2006 -0700"
      },
      "message": "[PATCH] ZVC: add __inc_zone_state for !SMP configuration\n\nIt turns out that there is a way to build a kernel with NUMA and no SMP.\nIn that case we are missing one definition __inc_zone_state.\n\nProvide that missing __inc_zone_state.\n\n(akpm: NUMA \u0026\u0026 !SMP sounds odd, but I am told \"But there is the concept of\ncpuless nodes.  A NUMA system without SMP has a single processor but multiple\nmemory nodes.  This used to work before on IA64 (wasn\u0027t aware of it, never seen\nanyone with this kind of thing).\")\n\nAcked-by: Tony Luck \u003ctony.luck@intel.com\u003e\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "e45b3b6af09dab2a28a7c88b340d0bcdd173e068",
      "tree": "54fe9104271396ceb02985be631debc55b18013a",
      "parents": [
        "1a91023a9f172f820e292f2c5675fb9f8e2636f0"
      ],
      "author": {
        "name": "Andrew Morton",
        "email": "akpm@osdl.org",
        "time": "Mon Jul 10 04:43:50 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Mon Jul 10 13:24:13 2006 -0700"
      },
      "message": "[PATCH] count_vm_events() fix\n\nDopey bug.  Causes hopelessly-wrong numbers from vmstat(8) and several other\ncounters.\n\nCc: Christoph Lameter \u003cclameter@engr.sgi.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "f8891e5e1f93a128c3900f82035e8541357896a7",
      "tree": "97b078ac97970962b17c85d39fd64cb48dc01168",
      "parents": [
        "ca889e6c45e0b112cb2ca9d35afc66297519b5d5"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:45 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:36 2006 -0700"
      },
      "message": "[PATCH] Light weight event counters\n\nThe remaining counters in page_state after the zoned VM counter patches\nhave been applied are all just for show in /proc/vmstat.  They have no\nessential function for the VM.\n\nWe use a simple increment of per cpu variables.  In order to avoid the most\nsevere races we disable preempt.  Preempt does not prevent the race between\nan increment and an interrupt handler incrementing the same statistics\ncounter.  However, that race is exceedingly rare, we may only loose one\nincrement or so and there is no requirement (at least not in kernel) that\nthe vm event counters have to be accurate.\n\nIn the non preempt case this results in a simple increment for each\ncounter.  For many architectures this will be reduced by the compiler to a\nsingle instruction.  This single instruction is atomic for i386 and x86_64.\n And therefore even the rare race condition in an interrupt is avoided for\nboth architectures in most cases.\n\nThe patchset also adds an off switch for embedded systems that allows a\nbuilding of linux kernels without these counters.\n\nThe implementation of these counters is through inline code that hopefully\nresults in only a single instruction increment instruction being emitted\n(i386, x86_64) or in the increment being hidden though instruction\nconcurrency (EPIC architectures such as ia64 can get that done).\n\nBenefits:\n- VM event counter operations usually reduce to a single inline instruction\n  on i386 and x86_64.\n- No interrupt disable, only preempt disable for the preempt case.\n  Preempt disable can also be avoided by moving the counter into a spinlock.\n- Handling is similar to zoned VM counters.\n- Simple and easily extendable.\n- Can be omitted to reduce memory use for embedded use.\n\nReferences:\n\nRFC http://marc.theaimsgroup.com/?l\u003dlinux-kernel\u0026m\u003d113512330605497\u0026w\u003d2\nRFC http://marc.theaimsgroup.com/?l\u003dlinux-kernel\u0026m\u003d114988082814934\u0026w\u003d2\nlocal_t http://marc.theaimsgroup.com/?l\u003dlinux-kernel\u0026m\u003d114991748606690\u0026w\u003d2\nV2 http://marc.theaimsgroup.com/?t\u003d115014808400007\u0026r\u003d1\u0026w\u003d2\nV3 http://marc.theaimsgroup.com/?l\u003dlinux-kernel\u0026m\u003d115024767022346\u0026w\u003d2\nV4 http://marc.theaimsgroup.com/?l\u003dlinux-kernel\u0026m\u003d115047968808926\u0026w\u003d2\n\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "ca889e6c45e0b112cb2ca9d35afc66297519b5d5",
      "tree": "0a5efdec2a61540204d34bcbf56dc691d8f9c391",
      "parents": [
        "bab1846a0582f627f5ec22aa2dc5f4f3e82e8176"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:44 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:36 2006 -0700"
      },
      "message": "[PATCH] Use Zoned VM Counters for NUMA statistics\n\nThe numa statistics are really event counters.  But they are per node and\nso we have had special treatment for these counters through additional\nfields on the pcp structure.  We can now use the per zone nature of the\nzoned VM counters to realize these.\n\nThis will shrink the size of the pcp structure on NUMA systems.  We will\nhave some room to add additional per zone counters that will all still fit\nin the same cacheline.\n\n Bits\tPrior pcp size\t  \tSize after patch\tWe can add\n ------------------------------------------------------------------\n 64\t128 bytes (16 words)\t80 bytes (10 words)\t48\n 32\t 76 bytes (19 words)\t56 bytes (14 words)\t8 (64 byte cacheline)\n\t\t\t\t\t\t\t72 (128 byte)\n\nRemove the special statistics for numa and replace them with zoned vm\ncounters.  This has the side effect that global sums of these events now\nshow up in /proc/vmstat.\n\nAlso take the opportunity to move the zone_statistics() function from\npage_alloc.c into vmstat.c.\n\nDiscussions:\nV2 http://marc.theaimsgroup.com/?t\u003d115048227000002\u0026r\u003d1\u0026w\u003d2\n\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nAcked-by: Andi Kleen \u003cak@suse.de\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "bab1846a0582f627f5ec22aa2dc5f4f3e82e8176",
      "tree": "79b6f31881f578a4db8a98ed97be4fc0db3f4ac1",
      "parents": [
        "c24f21bda88df4574de0a32a2a1558a23adae1b8"
      ],
      "author": {
        "name": "Andrew Morton",
        "email": "akpm@osdl.org",
        "time": "Fri Jun 30 01:55:43 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:36 2006 -0700"
      },
      "message": "[PATCH] zoned-vm-counters: remove read_page_state()\n\nNo callers.\n\nCc: Christoph Lameter \u003cclameter@engr.sgi.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "d2c5e30c9a1420902262aa923794d2ae4e0bc391",
      "tree": "b8c42c189c2bc8dd4b6d808ee8ed2b28dbd70ddd",
      "parents": [
        "fd39fc8561be33065306bdac0e30414e1e8ac8e1"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:41 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:36 2006 -0700"
      },
      "message": "[PATCH] zoned vm counters: conversion of nr_bounce to per zone counter\n\nConversion of nr_bounce to a per zone counter\n\nnr_bounce is only used for proc output.  So it could be left as an event\ncounter.  However, the event counters may not be accurate and nr_bounce is\ncategorizing types of pages in a zone.  So we really need this to also be a\nper zone counter.\n\n[akpm@osdl.org: bugfix]\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "fd39fc8561be33065306bdac0e30414e1e8ac8e1",
      "tree": "ae0740716eed3f850a8f7232c61caebe360bb5ae",
      "parents": [
        "ce866b34ae1b7f1ce60234cf65855886ac7e7d30"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:40 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:36 2006 -0700"
      },
      "message": "[PATCH] zoned vm counters: conversion of nr_unstable to per zone counter\n\nConversion of nr_unstable to a per zone counter\n\nWe need to do some special modifications to the nfs code since there are\nmultiple cases of disposition and we need to have a page ref for proper\naccounting.\n\nThis converts the last critical page state of the VM and therefore we need to\nremove several functions that were depending on GET_PAGE_STATE_LAST in order\nto make the kernel compile again.  We are only left with event type counters\nin page state.\n\n[akpm@osdl.org: bugfixes]\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nCc: Trond Myklebust \u003ctrond.myklebust@fys.uio.no\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "ce866b34ae1b7f1ce60234cf65855886ac7e7d30",
      "tree": "e9a2664f0abc5221b9a92e1417d8e02b94a634c4",
      "parents": [
        "b1e7a8fd854d2f895730e82137400012b509650e"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:40 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:35 2006 -0700"
      },
      "message": "[PATCH] zoned vm counters: conversion of nr_writeback to per zone counter\n\nConversion of nr_writeback to per zone counter.\n\nThis removes the last page_state counter from arch/i386/mm/pgtable.c so we\ndrop the page_state from there.\n\n[akpm@osdl.org: bugfix]\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nCc: Trond Myklebust \u003ctrond.myklebust@fys.uio.no\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "b1e7a8fd854d2f895730e82137400012b509650e",
      "tree": "9fba87ff6b0146ebd4ee5bc7d5f0c8b037dbb3ad",
      "parents": [
        "df849a1529c106f7460e51479ca78fe07b07dc8c"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:39 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:35 2006 -0700"
      },
      "message": "[PATCH] zoned vm counters: conversion of nr_dirty to per zone counter\n\nThis makes nr_dirty a per zone counter.  Looping over all processors is\navoided during writeback state determination.\n\nThe counter aggregation for nr_dirty had to be undone in the NFS layer since\nwe summed up the page counts from multiple zones.  Someone more familiar with\nNFS should probably review what I have done.\n\n[akpm@osdl.org: bugfix]\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nCc: Trond Myklebust \u003ctrond.myklebust@fys.uio.no\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "df849a1529c106f7460e51479ca78fe07b07dc8c",
      "tree": "f0e52e4720160aa7540a57715c247dce44584cbc",
      "parents": [
        "9a865ffa34b6117a5e0b67640a084d8c2e198c93"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:38 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:35 2006 -0700"
      },
      "message": "[PATCH] zoned vm counters: conversion of nr_pagetables to per zone counter\n\nConversion of nr_page_table_pages to a per zone counter\n\n[akpm@osdl.org: bugfix]\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "9a865ffa34b6117a5e0b67640a084d8c2e198c93",
      "tree": "c295d5a0831df81eeeded3834f32f513b9ae05c7",
      "parents": [
        "34aa1330f9b3c5783d269851d467326525207422"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:38 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:35 2006 -0700"
      },
      "message": "[PATCH] zoned vm counters: conversion of nr_slab to per zone counter\n\n- Allows reclaim to access counter without looping over processor counts.\n\n- Allows accurate statistics on how many pages are used in a zone by\n  the slab. This may become useful to balance slab allocations over\n  various zones.\n\n[akpm@osdl.org: bugfix]\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "65ba55f500a37272985d071c9bbb35256a2f7c14",
      "tree": "e7735326ef2d2dca9d00a6c5ae47e9eb03c7834f",
      "parents": [
        "2244b95a7bcf8d24196f8a3a44187ba5dfff754c"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:34 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:34 2006 -0700"
      },
      "message": "[PATCH] zoned vm counters: convert nr_mapped to per zone counter\n\nnr_mapped is important because it allows a determination of how many pages of\na zone are not mapped, which would allow a more efficient means of determining\nwhen we need to reclaim memory in a zone.\n\nWe take the nr_mapped field out of the page state structure and define a new\nper zone counter named NR_FILE_MAPPED (the anonymous pages will be split off\nfrom NR_MAPPED in the next patch).\n\nWe replace the use of nr_mapped in various kernel locations.  This avoids the\nlooping over all processors in try_to_free_pages(), writeback, reclaim (swap +\nzone reclaim).\n\n[akpm@osdl.org: bugfix]\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nCc: Trond Myklebust \u003ctrond.myklebust@fys.uio.no\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "2244b95a7bcf8d24196f8a3a44187ba5dfff754c",
      "tree": "771ef8eae45c2794fd73f870109c74d67c28888a",
      "parents": [
        "f6ac2354d791195ca40822b84d73d48a4e8b7f2b"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:33 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:34 2006 -0700"
      },
      "message": "[PATCH] zoned vm counters: basic ZVC (zoned vm counter) implementation\n\nPer zone counter infrastructure\n\nThe counters that we currently have for the VM are split per processor.  The\nprocessor however has not much to do with the zone these pages belong to.  We\ncannot tell f.e.  how many ZONE_DMA pages are dirty.\n\nSo we are blind to potentially inbalances in the usage of memory in various\nzones.  F.e.  in a NUMA system we cannot tell how many pages are dirty on a\nparticular node.  If we knew then we could put measures into the VM to balance\nthe use of memory between different zones and different nodes in a NUMA\nsystem.  For example it would be possible to limit the dirty pages per node so\nthat fast local memory is kept available even if a process is dirtying huge\namounts of pages.\n\nAnother example is zone reclaim.  We do not know how many unmapped pages exist\nper zone.  So we just have to try to reclaim.  If it is not working then we\npause and try again later.  It would be better if we knew when it makes sense\nto reclaim unmapped pages from a zone.  This patchset allows the determination\nof the number of unmapped pages per zone.  We can remove the zone reclaim\ninterval with the counters introduced here.\n\nFuthermore the ability to have various usage statistics available will allow\nthe development of new NUMA balancing algorithms that may be able to improve\nthe decision making in the scheduler of when to move a process to another node\nand hopefully will also enable automatic page migration through a user space\nprogram that can analyse the memory load distribution and then rebalance\nmemory use in order to increase performance.\n\nThe counter framework here implements differential counters for each processor\nin struct zone.  The differential counters are consolidated when a threshold\nis exceeded (like done in the current implementation for nr_pageache), when\nslab reaping occurs or when a consolidation function is called.\n\nConsolidation uses atomic operations and accumulates counters per zone in the\nzone structure and also globally in the vm_stat array.  VM functions can\naccess the counts by simply indexing a global or zone specific array.\n\nThe arrangement of counters in an array also simplifies processing when output\nhas to be generated for /proc/*.\n\nCounters can be updated by calling inc/dec_zone_page_state or\n_inc/dec_zone_page_state analogous to *_page_state.  The second group of\nfunctions can be called if it is known that interrupts are disabled.\n\nSpecial optimized increment and decrement functions are provided.  These can\navoid certain checks and use increment or decrement instructions that an\narchitecture may provide.\n\nWe also add a new CONFIG_DMA_IS_NORMAL that signifies that an architecture can\ndo DMA to all memory and therefore ZONE_NORMAL will not be populated.  This is\nonly currently set for IA64 SGI SN2 and currently only affects\nnode_page_state().  In the best case node_page_state can be reduced to\nretrieving a single counter for the one zone on the node.\n\n[akpm@osdl.org: cleanups]\n[akpm@osdl.org: export vm_stat[] for filesystems]\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nCc: Trond Myklebust \u003ctrond.myklebust@fys.uio.no\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "f6ac2354d791195ca40822b84d73d48a4e8b7f2b",
      "tree": "5f600175cf3591eac3d32bb8cebfd45d0aabf804",
      "parents": [
        "672b2714ae57af16fe7d760dc4e0918a7a6cb0fa"
      ],
      "author": {
        "name": "Christoph Lameter",
        "email": "clameter@sgi.com",
        "time": "Fri Jun 30 01:55:32 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Jun 30 11:25:34 2006 -0700"
      },
      "message": "[PATCH] zoned vm counters: create vmstat.c/.h from page_alloc.c/.h\n\nNOTE: ZVC are *not* the lightweight event counters.  ZVCs are reliable whereas\nevent counters do not need to be.\n\nZone based VM statistics are necessary to be able to determine what the state\nof memory in one zone is.  In a NUMA system this can be helpful for local\nreclaim and other memory optimizations that may be able to shift VM load in\norder to get more balanced memory use.\n\nIt is also useful to know how the computing load affects the memory\nallocations on various zones.  This patchset allows the retrieval of that data\nfrom userspace.\n\nThe patchset introduces a framework for counters that is a cross between the\nexisting page_stats --which are simply global counters split per cpu-- and the\napproach of deferred incremental updates implemented for nr_pagecache.\n\nSmall per cpu 8 bit counters are added to struct zone.  If the counter exceeds\ncertain thresholds then the counters are accumulated in an array of\natomic_long in the zone and in a global array that sums up all zone values.\nThe small 8 bit counters are next to the per cpu page pointers and so they\nwill be in high in the cpu cache when pages are allocated and freed.\n\nAccess to VM counter information for a zone and for the whole machine is then\npossible by simply indexing an array (Thanks to Nick Piggin for pointing out\nthat approach).  The access to the total number of pages of various types does\nno longer require the summing up of all per cpu counters.\n\nBenefits of this patchset right now:\n\n- Ability for UP and SMP configuration to determine how memory\n  is balanced between the DMA, NORMAL and HIGHMEM zones.\n\n- loops over all processors are avoided in writeback and\n  reclaim paths. We can avoid caching the writeback information\n  because the needed information is directly accessible.\n\n- Special handling for nr_pagecache removed.\n\n- zone_reclaim_interval vanishes since VM stats can now determine\n  when it is worth to do local reclaim.\n\n- Fast inline per node page state determination.\n\n- Accurate counters in /sys/devices/system/node/node*/meminfo. Current\n  counters are counting simply which processor allocated a page somewhere\n  and guestimate based on that. So the counters were not useful to show\n  the actual distribution of page use on a specific zone.\n\n- The swap_prefetch patch requires per node statistics in order to\n  figure out when processors of a node can prefetch. This patch provides\n  some of the needed numbers.\n\n- Detailed VM counters available in more /proc and /sys status files.\n\nReferences to earlier discussions:\nV1 http://marc.theaimsgroup.com/?l\u003dlinux-kernel\u0026m\u003d113511649910826\u0026w\u003d2\nV2 http://marc.theaimsgroup.com/?l\u003dlinux-kernel\u0026m\u003d114980851924230\u0026w\u003d2\nV3 http://marc.theaimsgroup.com/?l\u003dlinux-kernel\u0026m\u003d115014697910351\u0026w\u003d2\nV4 http://marc.theaimsgroup.com/?l\u003dlinux-kernel\u0026m\u003d115024767318740\u0026w\u003d2\n\nPerformance tests with AIM7 did not show any regressions.  Seems to be a tad\nfaster even.  Tested on ia64/NUMA.  Builds fine on i386, SMP / UP.  Includes\nfixes for s390/arm/uml arch code.\n\nThis patch:\n\nMove counter code from page_alloc.c/page-flags.h to vmstat.c/h.\n\nCreate vmstat.c/vmstat.h by separating the counter code and the proc\nfunctions.\n\nMove the vm_stat_text array before zoneinfo_show.\n\n[akpm@osdl.org: s390 build fix]\n[akpm@osdl.org: HOTPLUG_CPU build fix]\nSigned-off-by: Christoph Lameter \u003cclameter@sgi.com\u003e\nCc: Heiko Carstens \u003cheiko.carstens@de.ibm.com\u003e\nCc: Martin Schwidefsky \u003cschwidefsky@de.ibm.com\u003e\nCc: Trond Myklebust \u003ctrond.myklebust@fys.uio.no\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    }
  ]
}