Bump the flush stripe batch size to 2048. For my 12 disks raid array, the stripes takes: 12 * 4k * 2048 = 96MB This is still quite small. A hardware raid card generally has 1GB size, which we suggest the raid5-cache has similar cache size. The advantage of a big batch size is we can dispatch a lot of IO in the same time, then we can do some scheduling to make better IO pattern. Last patch prioritizes stripes, so we don't worry about a big flush stripe batch will starve normal stripes. Signed-off-by: Shaohua Li <shli@xxxxxx> --- drivers/md/raid5-cache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 3f307be..b25512c 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -43,7 +43,7 @@ /* wake up reclaim thread periodically */ #define R5C_RECLAIM_WAKEUP_INTERVAL (30 * HZ) /* start flush with these full stripes */ -#define R5C_FULL_STRIPE_FLUSH_BATCH 256 +#define R5C_FULL_STRIPE_FLUSH_BATCH 2048 /* reclaim stripes in groups */ #define R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2) -- 2.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
