linux-hardened/mm
Hugh Dickins 3399446632 swap: discard while swapping only if SWAP_FLAG_DISCARD
Tests with recent firmware on Intel X25-M 80GB and OCZ Vertex 60GB SSDs
show a shift since I last tested in December: in part because of firmware
updates, in part because of the necessary move from barriers to awaiting
completion at the block layer.  While discard at swapon still shows as
slightly beneficial on both, discarding 1MB swap cluster when allocating
is now disadvanteous: adds 25% overhead on Intel, adds 230% on OCZ (YMMV).

Surrender: discard as presently implemented is more hindrance than help
for swap; but might prove useful on other devices, or with improvements.
So continue to do the discard at swapon, but make discard while swapping
conditional on a SWAP_FLAG_DISCARD to sys_swapon() (which has been using
only the lower 16 bits of int flags).

We can add a --discard or -d to swapon(8), and a "discard" to swap in
/etc/fstab: matching the mount option for btrfs, ext4, fat, gfs2, nilfs2.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nigel Cunningham <nigel@tuxonice.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09 18:57:25 -07:00
..
backing-dev.c writeback: avoid unnecessary calculation of bdi dirty thresholds 2010-08-12 08:43:29 -07:00
bootmem.c x86,nobootmem: make alloc_bootmem_node fall back to other node when 32bit numa is used 2010-07-20 16:25:40 -07:00
bounce.c bounce: call flush_dcache_page() after bounce_copy_vec() 2010-09-09 18:57:25 -07:00
compaction.c mm: compaction: handle active and inactive fairly in too_many_isolated 2010-09-09 18:57:24 -07:00
debug-pagealloc.c
dmapool.c dmapools: protect page_list walk in show_pools() 2009-06-30 18:56:00 -07:00
fadvise.c readahead: introduce FMODE_RANDOM for POSIX_FADV_RANDOM 2010-03-06 11:26:25 -08:00
failslab.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
filemap.c gcc-4.6: mm: fix unused but set warnings 2010-08-09 20:44:58 -07:00
filemap_xip.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fremap.c mm: clean up mm_counter 2010-03-06 11:26:23 -08:00
highmem.c mm,kdb,kgdb: Add a debug reference for the kdb kmap usage 2010-08-05 09:22:24 -05:00
hugetlb.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2010-08-12 10:15:10 -07:00
hwpoison-inject.c HWPOISON, hugetlb: support hwpoison injection for hugepage 2010-08-11 09:23:11 +02:00
init-mm.c mm: provide init_mm mm_context initializer 2010-08-09 20:44:54 -07:00
internal.h HWPOISON: add an interface to switch off/on all the page filters 2009-12-16 12:19:59 +01:00
Kconfig mm: avoid warning when COMPACTION is selected 2010-09-09 18:57:24 -07:00
Kconfig.debug trivial: improve help text for mm debug config options 2009-09-21 15:14:57 +02:00
kmemcheck.c kmemcheck: Fix build errors due to missing slab.h 2010-03-30 22:02:32 +09:00
kmemleak-test.c percpu: clean up percpu variable definitions 2009-06-24 15:13:48 +09:00
kmemleak.c kmemleak: Fix typo in the comment 2010-08-08 21:57:23 +01:00
ksm.c mm: fix swapin race condition 2010-09-09 18:57:24 -07:00
maccess.c maccess,probe_kernel: Allow arch specific override probe_kernel_(read|write) 2010-01-07 11:58:36 -06:00
madvise.c HWPOISON: Add a madvise() injector for soft page offlining 2009-12-16 12:20:00 +01:00
Makefile lmb: rename to memblock 2010-07-14 17:14:00 +10:00
memblock.c memblock: Fix memblock_is_region_reserved() to return a boolean 2010-08-09 11:21:38 +10:00
memcontrol.c memcg: convert to use zone_to_nid() from bare zone->zone_pgdat->node_id 2010-08-11 08:59:19 -07:00
memory-failure.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2010-08-12 10:15:10 -07:00
memory.c mm: fix swapin race condition 2010-09-09 18:57:24 -07:00
memory_hotplug.c memory hotplug: fix next block calculation in is_removable 2010-09-09 18:57:24 -07:00
mempolicy.c mempolicy: reduce stack size of migrate_pages() 2010-08-09 20:44:58 -07:00
mempool.c mm: remove broken 'kzalloc' mempool 2009-09-22 07:17:35 -07:00
migrate.c mm: extend KSM refcounts to the anon_vma root 2010-08-09 20:44:55 -07:00
mincore.c mincore: do nested page table walks 2010-05-25 08:06:58 -07:00
mlock.c mm: Move vma_stack_continue into mm.h 2010-09-09 09:05:06 -07:00
mm_init.c
mmap.c guard page for stacks that grow upwards 2010-08-24 12:13:20 -07:00
mmu_context.c exit: fix oops in sync_mm_rss 2010-03-24 16:31:21 -07:00
mmu_notifier.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mmzone.c
mprotect.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mremap.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
msync.c sanitize vfs_fsync calling conventions 2010-05-21 18:31:21 -04:00
nommu.c mm: make the vma list be doubly linked 2010-08-21 08:49:21 -07:00
oom_kill.c oom: __task_cred() need rcu_read_lock() 2010-08-20 09:34:55 -07:00
page-writeback.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2010-08-28 14:07:20 -07:00
page_alloc.c vmscan: kill prev_priority completely 2010-08-09 20:45:00 -07:00
page_cgroup.c kmemleak: Annotate false positive in init_section_page_cgroup() 2010-07-19 11:54:14 +01:00
page_io.c block: unify flags for struct bio and struct request 2010-08-07 18:20:39 +02:00
page_isolation.c
pagewalk.c pagemap: fix pfn calculation for hugepage 2010-04-07 08:38:04 -07:00
percpu-km.c percpu: implement kernel memory based chunk allocation 2010-05-01 08:30:50 +02:00
percpu-vm.c percpu: move vmalloc based chunk management into percpu-vm.c 2010-05-01 08:30:50 +02:00
percpu.c percpu: fix a mismatch between code and comment 2010-08-27 11:36:19 +02:00
percpu_up.c percpu: add __percpu notations to UP allocator 2010-08-07 14:20:53 +02:00
prio_tree.c
quicklist.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
readahead.c readahead.c: fix comment 2010-05-25 08:07:00 -07:00
rmap.c mm: fix hang on anon_vma->root->lock 2010-08-28 13:54:12 -07:00
shmem.c shmem: put_super must percpu_counter_destroy 2010-08-17 18:33:11 -07:00
slab.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 2010-08-22 10:08:52 -07:00
slob.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 2010-08-06 11:44:08 -07:00
slub.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 2010-08-06 11:44:08 -07:00
sparse-vmemmap.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sparse.c sparsemem: on no vmemmap path put mem_map on node high too 2010-05-25 08:06:56 -07:00
swap.c mm: export lru_cache_add_*() to modules 2010-05-25 15:06:06 +02:00
swap_state.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
swapfile.c swap: discard while swapping only if SWAP_FLAG_DISCARD 2010-09-09 18:57:25 -07:00
thrash.c mm: pass mm to grab_swap_token 2009-06-23 12:50:05 -07:00
truncate.c check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
util.c mm: use memdup_user 2010-08-09 20:44:54 -07:00
vmalloc.c Merge branch 'stable/xen-swiotlb-0.8.6' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen 2010-08-12 09:09:41 -07:00
vmscan.c memcg: remove nid and zid argument from mem_cgroup_soft_limit_reclaim() 2010-08-11 08:59:19 -07:00
vmstat.c vmscan: kill prev_priority completely 2010-08-09 20:45:00 -07:00