Use 512kb max readahead size, and 32kb min readahead size. The former helps io performance for common workloads. The latter will be used in the thrashing safe context readahead. CC: Jens Axboe <jens.axboe@xxxxxxxxxx> CC: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> CC: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> CC: Christian Ehrhardt <ehrhardt@xxxxxxxxxxxxxxxxxx> Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> --- include/linux/mm.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- linux.orig/include/linux/mm.h 2010-01-30 17:38:49.000000000 +0800 +++ linux/include/linux/mm.h 2010-01-30 18:09:58.000000000 +0800 @@ -1184,8 +1184,8 @@ int write_one_page(struct page *page, in void task_dirty_inc(struct task_struct *tsk); /* readahead.c */ -#define VM_MAX_READAHEAD 128 /* kbytes */ -#define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */ +#define VM_MAX_READAHEAD 512 /* kbytes */ +#define VM_MIN_READAHEAD 32 /* kbytes (includes current page) */ int force_page_cache_readahead(struct address_space *mapping, struct file *filp, pgoff_t offset, unsigned long nr_to_read); -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
