From 584acdd49cd2472ca0f5a06adbe979db82d0b4af Mon Sep 17 00:00:00 2001 From: Markus Stockhausen Date: Mon, 15 Dec 2014 12:57:05 +1100 Subject: md/raid5: activate raid6 rmw feature Glue it altogehter. The raid6 rmw path should work the same as the already existing raid5 logic. So emulate the prexor handling/flags and split functions as needed. 1) Enable xor_syndrome() in the async layer. 2) Split ops_run_prexor() into RAID4/5 and RAID6 logic. Xor the syndrome at the start of a rmw run as we did it before for the single parity. 3) Take care of rmw run in ops_run_reconstruct6(). Again process only the changed pages to get syndrome back into sync. 4) Enhance set_syndrome_sources() to fill NULL pages if we are in a rmw run. The lower layers will calculate start & end pages from that and call the xor_syndrome() correspondingly. 5) Adapt the several places where we ignored Q handling up to now. Performance numbers for a single E5630 system with a mix of 10 7200k desktop/server disks. 300 seconds random write with 8 threads onto a 3,2TB (10*400GB) RAID6 64K chunk without spare (group_thread_cnt=4) bsize rmw_level=1 rmw_level=0 rmw_level=1 rmw_level=0 skip_copy=1 skip_copy=1 skip_copy=0 skip_copy=0 4K 115 KB/s 141 KB/s 165 KB/s 140 KB/s 8K 225 KB/s 275 KB/s 324 KB/s 274 KB/s 16K 434 KB/s 536 KB/s 640 KB/s 534 KB/s 32K 751 KB/s 1,051 KB/s 1,234 KB/s 1,045 KB/s 64K 1,339 KB/s 1,958 KB/s 2,282 KB/s 1,962 KB/s 128K 2,673 KB/s 3,862 KB/s 4,113 KB/s 3,898 KB/s 256K 7,685 KB/s 7,539 KB/s 7,557 KB/s 7,638 KB/s 512K 19,556 KB/s 19,558 KB/s 19,652 KB/s 19,688 Kb/s Signed-off-by: Markus Stockhausen Signed-off-by: NeilBrown --- drivers/md/raid5.h | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'drivers/md/raid5.h') diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index ee65ed844d3f..57fef9ba36fa 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -355,6 +355,23 @@ enum { STRIPE_OP_RECONSTRUCT, STRIPE_OP_CHECK, }; + +/* + * RAID parity calculation preferences + */ +enum { + PARITY_DISABLE_RMW = 0, + PARITY_ENABLE_RMW, +}; + +/* + * Pages requested from set_syndrome_sources() + */ +enum { + SYNDROME_SRC_ALL, + SYNDROME_SRC_WANT_DRAIN, + SYNDROME_SRC_WRITTEN, +}; /* * Plugging: * @@ -411,7 +428,7 @@ struct r5conf { spinlock_t hash_locks[NR_STRIPE_HASH_LOCKS]; struct mddev *mddev; int chunk_sectors; - int level, algorithm; + int level, algorithm, rmw_level; int max_degraded; int raid_disks; int max_nr_stripes; -- cgit