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| author | Markus Stockhausen <stockhausen@collogia.de> | 2014-12-15 12:57:05 +1100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2015-04-22 08:00:42 +1000 |
| commit | 584acdd49cd2472ca0f5a06adbe979db82d0b4af (patch) | |
| tree | 94abdc5ca0208e47275bc2a8ad82c2d25cefddfd /include/linux/async_tx.h | |
| parent | a582564b24bec0443b5c5ff43ee6d1258f8bd658 (diff) | |
| download | lwn-584acdd49cd2472ca0f5a06adbe979db82d0b4af.tar.gz lwn-584acdd49cd2472ca0f5a06adbe979db82d0b4af.zip | |
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 <stockhausen@collogia.de>
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'include/linux/async_tx.h')
| -rw-r--r-- | include/linux/async_tx.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/async_tx.h b/include/linux/async_tx.h index 179b38ffd351..388574ea38ed 100644 --- a/include/linux/async_tx.h +++ b/include/linux/async_tx.h @@ -60,12 +60,15 @@ struct dma_chan_ref { * dependency chain * @ASYNC_TX_FENCE: specify that the next operation in the dependency * chain uses this operation's result as an input + * @ASYNC_TX_PQ_XOR_DST: do not overwrite the syndrome but XOR it with the + * input data. Required for rmw case. */ enum async_tx_flags { ASYNC_TX_XOR_ZERO_DST = (1 << 0), ASYNC_TX_XOR_DROP_DST = (1 << 1), ASYNC_TX_ACK = (1 << 2), ASYNC_TX_FENCE = (1 << 3), + ASYNC_TX_PQ_XOR_DST = (1 << 4), }; /** |