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| author | Fengguang Wu <wfg@mail.ustc.edu.cn> | 2007-10-16 01:24:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-16 09:42:52 -0700 |
| commit | 0bb7ba6b9c358c12084a3cbc6ac08c8d1e973937 (patch) | |
| tree | 81dc745c660557af4d9ea8b9816846d0395ece20 | |
| parent | 937085aa35cc873d427d250a1e304d641af24628 (diff) | |
| download | lwn-0bb7ba6b9c358c12084a3cbc6ac08c8d1e973937.tar.gz lwn-0bb7ba6b9c358c12084a3cbc6ac08c8d1e973937.zip | |
readahead: mmap read-around simplification
Fold file_ra_state.mmap_hit into file_ra_state.mmap_miss and make it an int.
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/fs.h | 3 | ||||
| -rw-r--r-- | mm/filemap.c | 4 |
2 files changed, 3 insertions, 4 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 7a998c49a086..8250811081ff 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -703,8 +703,7 @@ struct file_ra_state { there are only # of pages ahead */ unsigned int ra_pages; /* Maximum readahead window */ - unsigned long mmap_hit; /* Cache hit stat for mmap accesses */ - unsigned long mmap_miss; /* Cache miss stat for mmap accesses */ + int mmap_miss; /* Cache miss stat for mmap accesses */ unsigned long prev_index; /* Cache last read() position */ unsigned int prev_offset; /* Offset where last read() ended in a page */ }; diff --git a/mm/filemap.c b/mm/filemap.c index 15c8413ee929..5dc18d76e703 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1349,7 +1349,7 @@ retry_find: * Do we miss much more than hit in this file? If so, * stop bothering with read-ahead. It will only hurt. */ - if (ra->mmap_miss > ra->mmap_hit + MMAP_LOTSAMISS) + if (ra->mmap_miss > MMAP_LOTSAMISS) goto no_cached_page; /* @@ -1375,7 +1375,7 @@ retry_find: } if (!did_readaround) - ra->mmap_hit++; + ra->mmap_miss--; /* * We have a locked page in the page cache, now we need to check |