linux/mm/page_alloc.c, branch v3.5

mm: cma: don't replace lowmem pages with highmem

2012-07-06T09:07:04Z

The filesystem layer expects pages in the block device's mapping to not be in highmem (the mapping's gfp mask is set in bdget()), but CMA can currently replace lowmem pages with highmem pages, leading to crashes in filesystem code such as the one below: Unable to handle kernel NULL pointer dereference at virtual address 00000400 pgd = c0c98000 [00000400] *pgd=00c91831, *pte=00000000, *ppte=00000000 Internal error: Oops: 817 [#1] PREEMPT SMP ARM CPU: 0 Not tainted (3.5.0-rc5+ #80) PC is at __memzero+0x24/0x80 ... Process fsstress (pid: 323, stack limit = 0xc0cbc2f0) Backtrace: [] (ext4_getblk+0x0/0x180) from [] (ext4_bread+0x1c/0x98) [] (ext4_bread+0x0/0x98) from [] (ext4_mkdir+0x160/0x3bc) r4:c15337f0 [] (ext4_mkdir+0x0/0x3bc) from [] (vfs_mkdir+0x8c/0x98) [] (vfs_mkdir+0x0/0x98) from [] (sys_mkdirat+0x74/0xac) r6:00000000 r5:c152eb40 r4:000001ff r3:c14b43f0 [] (sys_mkdirat+0x0/0xac) from [] (sys_mkdir+0x20/0x24) r6:beccdcf0 r5:00074000 r4:beccdbbc [] (sys_mkdir+0x0/0x24) from [] (ret_fast_syscall+0x0/0x30) Fix this by replacing only highmem pages with highmem. Reported-by: Laura Abbott Signed-off-by: Rabin Vincent Acked-by: Michal Nazarewicz Signed-off-by: Marek Szyprowski

Revert "mm: compaction: handle incorrect MIGRATE_UNMOVABLE type pageblocks"

2012-06-04T03:05:57Z

This reverts commit 5ceb9ce6fe9462a298bb2cd5c9f1ca6cb80a0199. That commit seems to be the cause of the mm compation list corruption issues that Dave Jones reported. The locking (or rather, absense there-of) is dubious, as is the use of the 'page' variable once it has been found to be outside the pageblock range. So revert it for now, we can re-visit this for 3.6. If we even need to: as Minchan Kim says, "The patch wasn't a bug fix and even test workload was very theoretical". Reported-and-tested-by: Dave Jones Acked-by: Hugh Dickins Acked-by: KOSAKI Motohiro Acked-by: Minchan Kim Cc: Bartlomiej Zolnierkiewicz Cc: Kyungmin Park Cc: Andrew Morton Signed-off-by: Linus Torvalds

mm: add link from struct lruvec to struct zone

2012-05-29T23:22:26Z

This is the first stage of struct mem_cgroup_zone removal. Further patches replace struct mem_cgroup_zone with a pointer to struct lruvec. If CONFIG_CGROUP_MEM_RES_CTLR=n lruvec_zone() is just container_of(). Signed-off-by: Konstantin Khlebnikov Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Acked-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/memcg: move reclaim_stat into lruvec

2012-05-29T23:22:25Z

With mem_cgroup_disabled() now explicit, it becomes clear that the zone_reclaim_stat structure actually belongs in lruvec, per-zone when memcg is disabled but per-memcg per-zone when it's enabled. We can delete mem_cgroup_get_reclaim_stat(), and change update_page_reclaim_stat() to update just the one set of stats, the one which get_scan_count() will actually use. Signed-off-by: Hugh Dickins Signed-off-by: Konstantin Khlebnikov Acked-by: KAMEZAWA Hiroyuki Acked-by: Michal Hocko Reviewed-by: Minchan Kim Reviewed-by: Michal Hocko Cc: Glauber Costa Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/page_alloc.c: cleanups

2012-05-29T23:22:23Z

- make pageflag_names[] const - remove null termination of pageflag_names[] Cc: Johannes Weiner Cc: Gavin Shan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: page_alloc: catch out-of-date list of page flag names

2012-05-29T23:22:23Z

String tables with names of enum items are always prone to go out of sync with the enums themselves. Ensure during compile time that the name table of page flags has the same size as the page flags enum. Signed-off-by: Johannes Weiner Cc: Gavin Shan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/buddy: dump PG_compound_lock page flag

2012-05-29T23:22:23Z

The array pageflag_names[] does conversion from page flags into their corresponding names so that a meaningful representation of the corresponding page flag can be printed. This mechanism is used while dumping page frames. However, the array missed PG_compound_lock. So the PG_compound_lock page flag would be printed as a digital number instead of a meaningful string. The patch fixes that and prints "compound_lock" for the PG_compound_lock page flag. Signed-off-by: Gavin Shan Acked-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: compaction: handle incorrect MIGRATE_UNMOVABLE type pageblocks

2012-05-29T23:22:22Z

When MIGRATE_UNMOVABLE pages are freed from MIGRATE_UNMOVABLE type pageblock (and some MIGRATE_MOVABLE pages are left in it) waiting until an allocation takes ownership of the block may take too long. The type of the pageblock remains unchanged so the pageblock cannot be used as a migration target during compaction. Fix it by: * Adding enum compact_mode (COMPACT_ASYNC_[MOVABLE,UNMOVABLE], and COMPACT_SYNC) and then converting sync field in struct compact_control to use it. * Adding nr_pageblocks_skipped field to struct compact_control and tracking how many destination pageblocks were of MIGRATE_UNMOVABLE type. If COMPACT_ASYNC_MOVABLE mode compaction ran fully in try_to_compact_pages() (COMPACT_COMPLETE) it implies that there is not a suitable page for allocation. In this case then check how if there were enough MIGRATE_UNMOVABLE pageblocks to try a second pass in COMPACT_ASYNC_UNMOVABLE mode. * Scanning the MIGRATE_UNMOVABLE pageblocks (during COMPACT_SYNC and COMPACT_ASYNC_UNMOVABLE compaction modes) and building a count based on finding PageBuddy pages, page_count(page) == 0 or PageLRU pages. If all pages within the MIGRATE_UNMOVABLE pageblock are in one of those three sets change the whole pageblock type to MIGRATE_MOVABLE. My particular test case (on a ARM EXYNOS4 device with 512 MiB, which means 131072 standard 4KiB pages in 'Normal' zone) is to: - allocate 120000 pages for kernel's usage - free every second page (60000 pages) of memory just allocated - allocate and use 60000 pages from user space - free remaining 60000 pages of kernel memory (now we have fragmented memory occupied mostly by user space pages) - try to allocate 100 order-9 (2048 KiB) pages for kernel's usage The results: - with compaction disabled I get 11 successful allocations - with compaction enabled - 14 successful allocations - with this patch I'm able to get all 100 successful allocations NOTE: If we can make kswapd aware of order-0 request during compaction, we can enhance kswapd with changing mode to COMPACT_ASYNC_FULL (COMPACT_ASYNC_MOVABLE + COMPACT_ASYNC_UNMOVABLE). Please see the following thread: http://marc.info/?l=linux-mm&m=133552069417068&w=2 [minchan@kernel.org: minor cleanups] Cc: Mel Gorman Cc: Minchan Kim Cc: Rik van Riel Cc: Marek Szyprowski Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/page_alloc.c: remove pageblock_default_order()

2012-05-29T23:22:21Z

This has always been broken: one version takes an unsigned int and the other version takes no arguments. This bug was hidden because one version of set_pageblock_order() was a macro which doesn't evaluate its argument. Simplify it all and remove pageblock_default_order() altogether. Reported-by: rajman mekaco Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Cc: Tejun Heo Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: print physical addresses consistently with other parts of kernel

2012-05-29T23:22:21Z

Print physical address info in a style consistent with the %pR style used elsewhere in the kernel. For example: -Zone PFN ranges: +Zone ranges: - DMA32 0x00000010 -> 0x00100000 + DMA32 [mem 0x00010000-0xffffffff] - Normal 0x00100000 -> 0x01080000 + Normal [mem 0x100000000-0x107fffffff] Signed-off-by: Bjorn Helgaas Cc: Yinghai Lu Cc: Konrad Rzeszutek Wilk Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds