From: Gao Xiang <hsiangkao@xxxxxxx> Subject: mm/readahead.c: simplify get_next_ra_size() It's a trivial simplification for get_next_ra_size() and clear enough for humans to understand. It also fixes potential overflow if ra->size(< ra_pages) is too large. Link: http://lkml.kernel.org/r/1540707206-19649-1-git-send-email-hsiangkao@xxxxxxx Signed-off-by: Gao Xiang <hsiangkao@xxxxxxx> Reviewed-by: Fengguang Wu <fengguang.wu@xxxxxxxxx> Reviewed-by: Matthew Wilcox <willy@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- --- a/mm/readahead.c~mm-simplify-get_next_ra_size +++ a/mm/readahead.c @@ -270,17 +270,15 @@ static unsigned long get_init_ra_size(un * return it as the new window size. */ static unsigned long get_next_ra_size(struct file_ra_state *ra, - unsigned long max) + unsigned long max) { unsigned long cur = ra->size; - unsigned long newsize; if (cur < max / 16) - newsize = 4 * cur; - else - newsize = 2 * cur; - - return min(newsize, max); + return 4 * cur; + if (cur <= max / 2) + return 2 * cur; + return max; } /* _
