Messages in this thread Patch in this message | | | Date | Sat, 22 Dec 2007 09:31:51 +0800 | From | Fengguang Wu <> | Subject | [PATCH 4/9] readahead: quick startup on sequential mmap readahead |
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When the user explicitly sets MADV_SEQUENTIAL, we should really avoid the slow readahead size ramp-up phase and start full-size readahead immediately.
This patch won't change behavior for the auto-detected sequential mmap reads. Its previous read-around size is ra_pages/2, so it will be doubled to the full readahead size anyway.
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> --- mm/filemap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- linux-2.6.24-rc5-mm1.orig/mm/filemap.c +++ linux-2.6.24-rc5-mm1/mm/filemap.c @@ -1320,7 +1320,7 @@ static void do_sync_mmap_readahead(struc if (VM_SequentialReadHint(vma) || offset - 1 == (ra->prev_pos >> PAGE_CACHE_SHIFT)) { - page_cache_sync_readahead(mapping, ra, file, offset, 1); + page_cache_sync_readahead(mapping, ra, file, offset, ra->ra_pages); return; } --
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