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| author | Arve Hjønnevåg <arve@android.com> | 2011-05-24 17:12:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-25 08:39:24 -0700 |
| commit | 6d3163ce86dd386b4f7bda80241d7fea2bc0bb1d (patch) | |
| tree | 169f74df152fa593e5dc9adfff7f6f7e31061028 /mm/readahead.c | |
| parent | 0091a47da0b720ca39511c7d90dcc768cafcaf58 (diff) | |
| download | linux-6d3163ce86dd386b4f7bda80241d7fea2bc0bb1d.tar.gz | |
mm: check if any page in a pageblock is reserved before marking it MIGRATE_RESERVE
This fixes a problem where the first pageblock got marked MIGRATE_RESERVE even though it only had a few free pages. eg, On current ARM port, The kernel starts at offset 0x8000 to leave room for boot parameters, and the memory is freed later. This in turn caused no contiguous memory to be reserved and frequent kswapd wakeups that emptied the caches to get more contiguous memory. Unfortunatelly, ARM needs order-2 allocation for pgd (see arm/mm/pgd.c#pgd_alloc()). Therefore the issue is not minor nor easy avoidable. [kosaki.motohiro@jp.fujitsu.com: added some explanation] [kosaki.motohiro@jp.fujitsu.com: add !pfn_valid_within() to check] [minchan.kim@gmail.com: check end_pfn in pageblock_is_reserved] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/readahead.c')
0 files changed, 0 insertions, 0 deletions