linux/mm
Vlastimil Babka baf6a9a1db mm, compaction: finish whole pageblock to reduce fragmentation
The main goal of direct compaction is to form a high-order page for
allocation, but it should also help against long-term fragmentation when
possible.

Most lower-than-pageblock-order compactions are for non-movable
allocations, which means that if we compact in a movable pageblock and
terminate as soon as we create the high-order page, it's unlikely that
the fallback heuristics will claim the whole block.  Instead there might
be a single unmovable page in a pageblock full of movable pages, and the
next unmovable allocation might pick another pageblock and increase
long-term fragmentation.

To help against such scenarios, this patch changes the termination
criteria for compaction so that the current pageblock is finished even
though the high-order page already exists.  Note that it might be
possible that the high-order page formed elsewhere in the zone due to
parallel activity, but this patch doesn't try to detect that.

This is only done with sync compaction, because async compaction is
limited to pageblock of the same migratetype, where it cannot result in
a migratetype fallback.  (Async compaction also eagerly skips
order-aligned blocks where isolation fails, which is against the goal of
migrating away as much of the pageblock as possible.)

As a result of this patch, long-term memory fragmentation should be
reduced.

In testing based on 4.9 kernel with stress-highalloc from mmtests
configured for order-4 GFP_KERNEL allocations, this patch has reduced
the number of unmovable allocations falling back to movable pageblocks
by 20%.  The number

Link: http://lkml.kernel.org/r/20170307131545.28577-9-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:10 -07:00
..
kasan kasan: separate report parts by empty lines 2017-05-03 15:52:12 -07:00
backing-dev.c bdi: Drop 'parent' argument from bdi_register[_va]() 2017-04-20 12:09:55 -06:00
balloon_compaction.c
bootmem.c mm/bootmem.c: cosmetic improvement of code readability 2017-02-22 16:41:29 -08:00
cleancache.c
cma_debug.c cma: Store a name in the cma structure 2017-04-18 20:41:12 +02:00
cma.c cma: Introduce cma_for_each_area 2017-04-18 20:41:12 +02:00
cma.h cma: Store a name in the cma structure 2017-04-18 20:41:12 +02:00
compaction.c mm, compaction: finish whole pageblock to reduce fragmentation 2017-05-08 17:15:10 -07:00
debug_page_ref.c
debug.c mm, debug: print raw struct page data in __dump_page() 2016-12-12 18:55:08 -08:00
dmapool.c lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
early_ioremap.c
fadvise.c mm: fadvise: avoid expensive remote LRU cache draining after FADV_DONTNEED 2016-12-20 09:48:46 -08:00
failslab.c
filemap.c fs: fix data invalidation in the cleancache during direct IO 2017-05-03 15:52:12 -07:00
frame_vector.c
frontswap.c
gup.c mm/gup.c: fix access_ok() argument type 2017-05-03 15:52:12 -07:00
highmem.c
huge_memory.c mm: make ttu's return boolean 2017-05-03 15:52:10 -07:00
hugetlb_cgroup.c
hugetlb.c mm/hugetlb.c: don't call region_abort if region_chg fails 2017-03-31 17:13:30 -07:00
hwpoison-inject.c mm: hwpoison: call shake_page() unconditionally 2017-05-03 15:52:12 -07:00
init-mm.c mm: Add a user_ns owner to mm_struct and fix ptrace permission checks 2016-11-22 11:49:48 -06:00
internal.h mm, compaction: finish whole pageblock to reduce fragmentation 2017-05-08 17:15:10 -07:00
interval_tree.c
Kconfig mm: remove AVR32 arch special handling in mm/Kconfig 2017-05-01 09:36:31 +02:00
Kconfig.debug mm: enable page poisoning early at boot 2017-05-03 15:52:10 -07:00
khugepaged.c mm: do not use double negation for testing page flags 2017-05-03 15:52:09 -07:00
kmemcheck.c
kmemleak-test.c
kmemleak.c mm: fix section name for .data..ro_after_init 2017-03-31 17:13:30 -07:00
ksm.c mm: make rmap_one boolean function 2017-05-03 15:52:10 -07:00
list_lru.c
maccess.c
madvise.c mm/madvise: move up the behavior parameter validation 2017-05-03 15:52:11 -07:00
Makefile mm: add arch-independent testcases for RODATA 2017-02-27 18:43:48 -08:00
memblock.c memblock: add memblock_cap_memory_range() 2017-04-05 18:26:50 +01:00
memcontrol.c mm: memcontrol: use node page state naming scheme for memcg 2017-05-03 15:52:11 -07:00
memory_hotplug.c mm, vmscan: prevent kswapd sleeping prematurely due to mismatched classzone_idx 2017-05-03 15:52:09 -07:00
memory-failure.c mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page 2017-05-03 15:52:12 -07:00
memory.c Merge branch 'parisc-4.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux into uaccess.parisc 2017-04-02 10:33:48 -04:00
mempolicy.c mm/mempolicy.c: fix error handling in set_mempolicy and mbind. 2017-04-08 10:57:55 -07:00
mempool.c
memtest.c
migrate.c mm: make rmap_one boolean function 2017-05-03 15:52:10 -07:00
mincore.c mm: remove shmem_mapping() shmem_zero_setup() duplicates 2017-02-24 17:46:56 -08:00
mlock.c mm: make try_to_munlock() return void 2017-05-03 15:52:10 -07:00
mm_init.c
mmap.c mm/mmap: replace SHM_HUGE_MASK with MAP_HUGE_MASK inside mmap_pgoff 2017-05-03 15:52:10 -07:00
mmu_context.c sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
mmu_notifier.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h> 2017-03-02 08:42:28 +01:00
mmzone.c mm/mmzone.c: swap likely to unlikely as code logic is different for next_zones_zonelist() 2017-02-22 16:41:29 -08:00
mprotect.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
mremap.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
msync.c
nobootmem.c
nommu.c Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
oom_kill.c oom: improve oom disable handling 2017-05-03 15:52:10 -07:00
page_alloc.c mm, compaction: restrict async compaction to pageblocks of same migratetype 2017-05-08 17:15:10 -07:00
page_counter.c
page_ext.c mm: enable page poisoning early at boot 2017-05-03 15:52:10 -07:00
page_idle.c mm: make rmap_one boolean function 2017-05-03 15:52:10 -07:00
page_io.c
page_isolation.c mm, page_alloc: count movable pages when stealing from pageblock 2017-05-08 17:15:10 -07:00
page_owner.c
page_poison.c mm: enable page poisoning early at boot 2017-05-03 15:52:10 -07:00
page_vma_mapped.c mm: fix page_vma_mapped_walk() for ksm pages 2017-04-08 00:47:48 -07:00
page-writeback.c mm: memcontrol: use node page state naming scheme for memcg 2017-05-03 15:52:11 -07:00
pagewalk.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
percpu-km.c
percpu-vm.c percpu: remove unused chunk_alloc parameter from pcpu_get_pages() 2017-03-06 15:56:55 -05:00
percpu.c Merge branch 'sched/core' into locking/core 2017-04-04 11:31:12 +02:00
pgtable-generic.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
process_vm_access.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h> 2017-03-02 08:42:28 +01:00
quicklist.c
readahead.c mm: don't cap request size based on read-ahead setting 2016-12-12 18:55:08 -08:00
rmap.c mm: memcontrol: use node page state naming scheme for memcg 2017-05-03 15:52:11 -07:00
rodata_test.c mm: remove rodata_test_data export, add pr_fmt 2017-05-03 15:52:09 -07:00
shmem.c Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-03-03 11:38:56 -08:00
slab_common.c kasan: drain quarantine of memcg slab objects 2017-02-24 17:46:56 -08:00
slab.c slab: avoid IPIs when creating kmem caches 2017-05-03 15:52:07 -07:00
slab.h slab: remove synchronous synchronize_sched() from memcg cache deactivation path 2017-02-22 16:41:27 -08:00
slob.c slab: introduce __kmemcg_cache_deactivate() 2017-02-22 16:41:27 -08:00
slub.c slub: make sysfs directories for memcg sub-caches optional 2017-02-22 16:41:27 -08:00
sparse-vmemmap.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
sparse.c mm/sparse: refine usemap_size() a little 2017-05-03 15:52:09 -07:00
swap_cgroup.c mm, swap_cgroup: reschedule when neeed in swap_cgroup_swapoff() 2017-04-08 00:47:49 -07:00
swap_slots.c mm/swap_slots.c: add warning if swap slots cache failed to initialize 2017-05-03 15:52:10 -07:00
swap_state.c mm, swap: fix comment in __read_swap_cache_async 2017-05-03 15:52:10 -07:00
swap.c mm: move MADV_FREE pages into LRU_INACTIVE_FILE list 2017-05-03 15:52:08 -07:00
swapfile.c mm/swapfile.c: fix swap space leak in error path of swap_free_entries() 2017-05-03 15:52:12 -07:00
truncate.c mm/truncate: avoid pointless cleancache_invalidate_inode() calls. 2017-05-03 15:52:12 -07:00
usercopy.c mm/usercopy: Drop extra is_vmalloc_or_module() check 2017-04-05 12:30:18 -07:00
userfaultfd.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
util.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
vmacache.c sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
vmalloc.c A reasonably busy cycle for documentation this time around. There is a new 2017-05-02 10:21:17 -07:00
vmpressure.c mm: vmpressure: fix sending wrong events on underflow 2017-02-24 17:46:56 -08:00
vmscan.c mm: memcontrol: use node page state naming scheme for memcg 2017-05-03 15:52:11 -07:00
vmstat.c mm, vmstat: suppress pcp stats for unpopulated zones in zoneinfo 2017-05-03 15:52:08 -07:00
workingset.c mm: memcontrol: use node page state naming scheme for memcg 2017-05-03 15:52:11 -07:00
z3fold.c z3fold: fix page locking in z3fold_alloc() 2017-04-13 18:24:20 -07:00
zbud.c
zpool.c
zsmalloc.c zsmalloc: expand class bit 2017-04-13 18:24:21 -07:00
zswap.c zswap: don't param_set_charp while holding spinlock 2017-02-27 18:43:45 -08:00