On Thu, 2012-06-28 at 14:35 -0700, Andrew Morton wrote: > On Thu, 28 Jun 2012 17:24:25 -0400 Rik van Riel <riel@xxxxxxxxxx> wrote: > > > > >> @@ -463,6 +474,8 @@ static void isolate_freepages(struct zone *zone, > > >> */ > > >> if (isolated) > > >> high_pfn = max(high_pfn, pfn); > > >> + if (cc->order> 0) > > >> + zone->compact_cached_free_pfn = high_pfn; > > > > > > Is high_pfn guaranteed to be aligned to pageblock_nr_pages here? I > > > assume so, if lots of code in other places is correct but it's > > > unobvious from reading this function. > > > > Reading the code a few more times, I believe that it is > > indeed aligned to pageblock size. > > I'll slip this into -next for a while. > > --- a/mm/compaction.c~isolate_freepages-check-that-high_pfn-is-aligned-as-expected > +++ a/mm/compaction.c > @@ -456,6 +456,7 @@ static void isolate_freepages(struct zon > } > spin_unlock_irqrestore(&zone->lock, flags); > > + WARN_ON_ONCE(high_pfn & (pageblock_nr_pages - 1)); > /* > * Record the highest PFN we isolated pages from. When next > * looking for free pages, the search will restart here as I've triggered the following with today's -next: [ 372.893094] ------------[ cut here ]------------ [ 372.896319] WARNING: at mm/compaction.c:470 isolate_freepages+0x1d9/0x370() [ 372.898900] Pid: 11417, comm: trinity-child55 Tainted: G W 3.5.0-rc5-next-20120702-sasha-00007-g9a2ee81 #496 [ 372.902293] Call Trace: [ 372.903152] [<ffffffff810eb427>] warn_slowpath_common+0x87/0xb0 [ 372.905295] [<ffffffff810eb465>] warn_slowpath_null+0x15/0x20 [ 372.908327] [<ffffffff81207cd9>] isolate_freepages+0x1d9/0x370 [ 372.912093] [<ffffffff81207e98>] compaction_alloc+0x28/0x50 [ 372.916275] [<ffffffff81241c6c>] unmap_and_move+0x3c/0x140 [ 372.920132] [<ffffffff81241e30>] migrate_pages+0xc0/0x170 [ 372.924141] [<ffffffff81207e70>] ? isolate_freepages+0x370/0x370 [ 372.928388] [<ffffffff812087f2>] compact_zone+0x112/0x450 [ 372.932342] [<ffffffff81135488>] ? sched_clock_cpu+0x108/0x120 [ 372.935289] [<ffffffff81208f24>] compact_zone_order+0xb4/0xd0 [ 372.937439] [<ffffffff81208ff6>] try_to_compact_pages+0xb6/0x120 [ 372.939535] [<ffffffff811eae32>] __alloc_pages_direct_compact+0xc2/0x220 [ 372.941912] [<ffffffff811eb366>] __alloc_pages_slowpath+0x3d6/0x6a0 [ 372.948587] [<ffffffff811ead35>] ? get_page_from_freelist+0x625/0x660 [ 372.957577] [<ffffffff811eb876>] __alloc_pages_nodemask+0x246/0x330 [ 372.964765] [<ffffffff8122ea3f>] alloc_pages_vma+0x12f/0x140 [ 372.971493] [<ffffffff8124e9b4>] ? mem_cgroup_count_vm_event+0x144/0x170 [ 372.980908] [<ffffffff81247675>] do_huge_pmd_anonymous_page+0xf5/0x260 [ 372.988788] [<ffffffff81210573>] handle_mm_fault+0x1f3/0x360 [ 372.997296] [<ffffffff8120c037>] ? follow_page+0xe7/0x5a0 [ 373.000737] [<ffffffff81210bd8>] __get_user_pages+0x438/0x5d0 [ 373.003473] [<ffffffff81211cc6>] __mlock_vma_pages_range+0xc6/0xd0 [ 373.007813] [<ffffffff81211ec5>] mlock_vma_pages_range+0x75/0xb0 [ 373.010956] [<ffffffff81215adc>] mmap_region+0x4bc/0x5f0 [ 373.012891] [<ffffffff81215ec9>] do_mmap_pgoff+0x2b9/0x350 [ 373.015029] [<ffffffff812006bc>] ? vm_mmap_pgoff+0x6c/0xb0 [ 373.017098] [<ffffffff812006d4>] vm_mmap_pgoff+0x84/0xb0 [ 373.019086] [<ffffffff812133d2>] sys_mmap_pgoff+0x182/0x190 [ 373.021106] [<ffffffff8199070e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 373.025749] [<ffffffff8106d4dd>] sys_mmap+0x1d/0x20 [ 373.029489] [<ffffffff8373b5f9>] system_call_fastpath+0x16/0x1b [ 373.042335] ---[ end trace 6d450e935ee18981 ]--- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>