On 1/16/08, KOSAKI Motohiro <[EMAIL PROTECTED]> wrote: > Hi Daniel > > > > > The notification fires after only ~100 MB allocated, i.e., when page > > > > reclaim is beginning to nag from page cache. Isn't this a bit early? > > > > Repeating the test with swap enabled results in a notification after > > > > ~600 MB allocated, which is more reasonable and just before the system > > > > starts to swap. > > > > > > Your issue may have more to do with the fact that the > > > highmem zone is 128MB in size and some balancing issues > > > between __alloc_pages and try_to_free_pages. > > > > I don't think so. I ran the test again without highmem and noticed the > > same behaviour: > > Thank you for good point out! > Could you please post your test program and reproduced method?
Sure: 1. Fill almost all available memory with page cache in a system without swap. 2. Run attached alloc-test program. 3. Notification fires when page cache is reclaimed. Example: $ cat /bigfile > /dev/null $ cat /proc/meminfo MemTotal: 895876 kB MemFree: 94272 kB Buffers: 884 kB Cached: 782868 kB SwapCached: 0 kB Active: 15356 kB Inactive: 778000 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 895876 kB LowFree: 94272 kB SwapTotal: 0 kB SwapFree: 0 kB Dirty: 0 kB Writeback: 0 kB AnonPages: 9624 kB Mapped: 1352 kB Slab: 4220 kB SReclaimable: 1168 kB SUnreclaim: 3052 kB PageTables: 528 kB NFS_Unstable: 0 kB Bounce: 0 kB CommitLimit: 447936 kB Committed_AS: 28988 kB VmallocTotal: 122872 kB VmallocUsed: 904 kB VmallocChunk: 121864 kB $ ./test-alloc --------- Got notification, allocated 90 MB $ cat /proc/meminfo MemTotal: 895876 kB MemFree: 101960 kB Buffers: 888 kB Cached: 775200 kB SwapCached: 0 kB Active: 15356 kB Inactive: 770336 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 895876 kB LowFree: 101960 kB SwapTotal: 0 kB SwapFree: 0 kB Dirty: 28 kB Writeback: 0 kB AnonPages: 9624 kB Mapped: 1352 kB Slab: 4224 kB SReclaimable: 1168 kB SUnreclaim: 3056 kB PageTables: 532 kB NFS_Unstable: 0 kB Bounce: 0 kB CommitLimit: 447936 kB Committed_AS: 28988 kB VmallocTotal: 122872 kB VmallocUsed: 904 kB VmallocChunk: 121864 kB
alloc-test.c
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