linux/include
Hugh Dickins 2bcf887963 mm: take pagevecs off reclaim stack
Replace pagevecs in putback_lru_pages() and move_active_pages_to_lru()
by lists of pages_to_free: then apply Konstantin Khlebnikov's
free_hot_cold_page_list() to them instead of pagevec_release().

Which simplifies the flow (no need to drop and retake lock whenever
pagevec fills up) and reduces stale addresses in stack backtraces
(which often showed through the pagevecs); but more importantly,
removes another 120 bytes from the deepest stacks in page reclaim.
Although I've not recently seen an actual stack overflow here with
a vanilla kernel, move_active_pages_to_lru() has often featured in
deep backtraces.

However, free_hot_cold_page_list() does not handle compound pages
(nor need it: a Transparent HugePage would have been split by the
time it reaches the call in shrink_page_list()), but it is possible
for putback_lru_pages() or move_active_pages_to_lru() to be left
holding the last reference on a THP, so must exclude the unlikely
compound case before putting on pages_to_free.

Remove pagevec_strip(), its work now done in move_active_pages_to_lru().
The pagevec in scan_mapping_unevictable_pages() remains in mm/vmscan.c,
but that is never on the reclaim path, and cannot be replaced by a list.

Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:10 -08:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2011-11-07 10:13:52 -08:00
asm-generic thp: add tlb_remove_pmd_tlb_entry 2012-01-12 20:13:08 -08:00
crypto crypto: serpent-sse2 - add lrw support 2011-11-21 16:13:24 +08:00
drm Merge branch 'drm-core-next' of git://people.freedesktop.org/~airlied/linux 2012-01-10 11:04:36 -08:00
keys
linux mm: take pagevecs off reclaim stack 2012-01-12 20:13:10 -08:00
math-emu
media Merge branch 'depends/rmk/restart' into next/cleanup 2012-01-07 11:51:28 +00:00
misc
mtd mtd: document that MEMWRITE ioctl is NAND-specific 2012-01-09 18:18:36 +00:00
net Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs 2012-01-10 15:09:01 -08:00
pcmcia
rdma rdma/core: Fix sparse warnings 2012-01-04 09:17:45 -08:00
rxrpc
scsi SCSI updates for post 3.2 merge window 2012-01-10 10:36:08 -08:00
sound Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound 2012-01-12 08:00:30 -08:00
target target: remove the unused se_dev_list 2011-12-06 06:00:57 +00:00
trace vmscan/trace: Add 'file' info to trace_mm_vmscan_lru_isolate() 2012-01-12 20:13:08 -08:00
video ARM: OMAP: HWMOD: Unify DSS resets for OMAPs 2011-11-08 03:16:13 -07:00
xen Merge branch 'stable/for-linus-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen 2012-01-10 10:09:59 -08:00
Kbuild