From: Fengguang Wu Fold file_ra_state.mmap_hit into file_ra_state.mmap_miss and make it an int. Signed-off-by: Fengguang Wu Cc: Rusty Russell Signed-off-by: Andrew Morton --- include/linux/fs.h | 3 +-- mm/filemap.c | 4 ++-- 2 files changed, 3 insertions(+), 4 deletions(-) diff -puN include/linux/fs.h~readahead-mmap-read-around-simplification include/linux/fs.h --- a/include/linux/fs.h~readahead-mmap-read-around-simplification +++ a/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 -puN mm/filemap.c~readahead-mmap-read-around-simplification mm/filemap.c --- a/mm/filemap.c~readahead-mmap-read-around-simplification +++ a/mm/filemap.c @@ -1369,7 +1369,7 @@ 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; /* @@ -1395,7 +1395,7 @@ 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 _