linux/mm/migrate.c, branch v3.2.38

mm: compaction: introduce sync-light migration for use by compaction

2012-08-02T13:37:32Z

commit a6bc32b899223a877f595ef9ddc1e89ead5072b8 upstream. Stable note: Not tracked in Buzilla. This was part of a series that reduced interactivity stalls experienced when THP was enabled. These stalls were particularly noticable when copying data to a USB stick but the experiences for users varied a lot. This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT mode that avoids writing back pages to backing storage. Async compaction maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT. For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is used. This avoids sync compaction stalling for an excessive length of time, particularly when copying files to a USB stick where there might be a large number of dirty pages backed by a filesystem that does not support ->writepages. [aarcange@redhat.com: This patch is heavily based on Andrea's work] [akpm@linux-foundation.org: fix fs/nfs/write.c build] [akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build] Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Minchan Kim Cc: Dave Jones Cc: Jan Kara Cc: Andy Isaacson Cc: Nai Xia Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

mm: compaction: determine if dirty pages can be migrated without blocking within ->migratepage

2012-08-02T13:37:30Z

commit b969c4ab9f182a6e1b2a0848be349f99714947b0 upstream. Stable note: Not tracked in Bugzilla. A fix aimed at preserving page aging information by reducing LRU list churning had the side-effect of reducing THP allocation success rates. This was part of a series to restore the success rates while preserving the reclaim fix. Asynchronous compaction is used when allocating transparent hugepages to avoid blocking for long periods of time. Due to reports of stalling, there was a debate on disabling synchronous compaction but this severely impacted allocation success rates. Part of the reason was that many dirty pages are skipped in asynchronous compaction by the following check; if (PageDirty(page) && !sync && mapping->a_ops->migratepage != migrate_page) rc = -EBUSY; This skips over all mapping aops using buffer_migrate_page() even though it is possible to migrate some of these pages without blocking. This patch updates the ->migratepage callback with a "sync" parameter. It is the responsibility of the callback to fail gracefully if migration would block. Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Minchan Kim Cc: Dave Jones Cc: Jan Kara Cc: Andy Isaacson Cc: Nai Xia Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

mm/migrate.c: pair unlock_page() and lock_page() when migrating huge pages

2011-12-09T15:50:28Z

Avoid unlocking and unlocked page if we failed to lock it. Signed-off-by: Hillf Danton Cc: Naoya Horiguchi Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-07T03:44:47Z

* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include net: sch_generic remove redundant use of net: inet_timewait_sock doesnt need ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h

mm: migration: clean up unmap_and_move()

2011-11-01T00:30:45Z

unmap_and_move() is one a big messy function. Clean it up. Signed-off-by: Minchan Kim Reviewed-by: KOSAKI Motohiro Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: Rik van Riel Cc: Michal Hocko Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: Map most files to use export.h instead of module.h

2011-10-31T13:20:12Z

The files changed within are only using the EXPORT_SYMBOL macro variants. They are not using core modular infrastructure and hence don't need module.h but only the export.h header. Signed-off-by: Paul Gortmaker

mm: fix race between mremap and removing migration entry

2011-10-20T06:42:58Z

I don't usually pay much attention to the stale "? " addresses in stack backtraces, but this lucky report from Pawel Sikora hints that mremap's move_ptes() has inadequate locking against page migration. 3.0 BUG_ON(!PageLocked(p)) in migration_entry_to_page(): kernel BUG at include/linux/swapops.h:105! RIP: 0010:[] [] migration_entry_wait+0x156/0x160 [] handle_pte_fault+0xae1/0xaf0 [] ? __pte_alloc+0x42/0x120 [] ? do_huge_pmd_anonymous_page+0xab/0x310 [] handle_mm_fault+0x181/0x310 [] ? vma_adjust+0x537/0x570 [] do_page_fault+0x11d/0x4e0 [] ? do_mremap+0x2d5/0x570 [] page_fault+0x1f/0x30 mremap's down_write of mmap_sem, together with i_mmap_mutex or lock, and pagetable locks, were good enough before page migration (with its requirement that every migration entry be found) came in, and enough while migration always held mmap_sem; but not enough nowadays, when there's memory hotremove and compaction. The danger is that move_ptes() lets a migration entry dodge around behind remove_migration_pte()'s back, so it's in the old location when looking at the new, then in the new location when looking at the old. Either mremap's move_ptes() must additionally take anon_vma lock(), or migration's remove_migration_pte() must stop peeking for is_swap_entry() before it takes pagetable lock. Consensus chooses the latter: we prefer to add overhead to migration than to mremapping, which gets used by JVMs and by exec stack setup. Reported-and-tested-by: Paweł Sikora Signed-off-by: Hugh Dickins Acked-by: Andrea Arcangeli Acked-by: Mel Gorman Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds

migrate: don't account swapcache as shmem

2011-06-16T22:01:24Z

swapcache will reach the below code path in migrate_page_move_mapping, and swapcache is accounted as NR_FILE_PAGES but it's not accounted as NR_SHMEM. Hugh pointed out we must use PageSwapCache instead of comparing mapping to &swapper_space, to avoid build failure with CONFIG_SWAP=n. Signed-off-by: Andrea Arcangeli Acked-by: Hugh Dickins Cc: stable@kernel.org Signed-off-by: Linus Torvalds

mm: use refcounts for page_lock_anon_vma()

2011-05-25T15:39:19Z

Convert page_lock_anon_vma() over to use refcounts. This is done to prepare for the conversion of anon_vma from spinlock to mutex. Sadly this inceases the cost of page_lock_anon_vma() from one to two atomics, a follow up patch addresses this, lets keep that simple for now. Signed-off-by: Peter Zijlstra Reviewed-by: KAMEZAWA Hiroyuki Reviewed-by: KOSAKI Motohiro Acked-by: Hugh Dickins Cc: Benjamin Herrenschmidt Cc: David Miller Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Cc: Mel Gorman Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Fix common misspellings

2011-03-31T14:26:23Z

Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi