From: Fengguang Wu Use 'unsigned int' instead of 'unsigned long' for readahead sizes. This helps reduce memory consumption on 64bit CPU when a lot of files are opened. CC: Andi Kleen Signed-off-by: Fengguang Wu Cc: Rusty Russell Signed-off-by: Andrew Morton --- include/linux/fs.h | 8 ++++---- mm/readahead.c | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-) diff -puN include/linux/fs.h~readahead-compacting-file_ra_state include/linux/fs.h --- a/include/linux/fs.h~readahead-compacting-file_ra_state +++ a/include/linux/fs.h @@ -697,12 +697,12 @@ struct fown_struct { * Track a single file's readahead state */ struct file_ra_state { - pgoff_t start; /* where readahead started */ - unsigned long size; /* # of readahead pages */ - unsigned long async_size; /* do asynchronous readahead when + pgoff_t start; /* where readahead started */ + unsigned int size; /* # of readahead pages */ + unsigned int async_size; /* do asynchronous readahead when there are only # of pages ahead */ - unsigned long ra_pages; /* Maximum readahead window */ + 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 */ unsigned long prev_index; /* Cache last read() position */ diff -puN mm/readahead.c~readahead-compacting-file_ra_state mm/readahead.c --- a/mm/readahead.c~readahead-compacting-file_ra_state +++ a/mm/readahead.c @@ -351,7 +351,7 @@ ondemand_readahead(struct address_space bool hit_readahead_marker, pgoff_t offset, unsigned long req_size) { - unsigned long max; /* max readahead pages */ + int max; /* max readahead pages */ int sequential; max = ra->ra_pages; _