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 --- crypto/async_tx/async_pq.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) (limited to 'crypto') diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c index d05327caf69d..5d355e0c2633 100644 --- a/crypto/async_tx/async_pq.c +++ b/crypto/async_tx/async_pq.c @@ -124,6 +124,7 @@ do_sync_gen_syndrome(struct page **blocks, unsigned int offset, int disks, { void **srcs; int i; + int start = -1, stop = disks - 3; if (submit->scribble) srcs = submit->scribble; @@ -134,10 +135,21 @@ do_sync_gen_syndrome(struct page **blocks, unsigned int offset, int disks, if (blocks[i] == NULL) { BUG_ON(i > disks - 3); /* P or Q can't be zero */ srcs[i] = (void*)raid6_empty_zero_page; - } else + } else { srcs[i] = page_address(blocks[i]) + offset; + if (i < disks - 2) { + stop = i; + if (start == -1) + start = i; + } + } } - raid6_call.gen_syndrome(disks, len, srcs); + if (submit->flags & ASYNC_TX_PQ_XOR_DST) { + BUG_ON(!raid6_call.xor_syndrome); + if (start >= 0) + raid6_call.xor_syndrome(disks, start, stop, len, srcs); + } else + raid6_call.gen_syndrome(disks, len, srcs); async_tx_sync_epilog(submit); } @@ -178,7 +190,8 @@ async_gen_syndrome(struct page **blocks, unsigned int offset, int disks, if (device) unmap = dmaengine_get_unmap_data(device->dev, disks, GFP_NOIO); - if (unmap && + /* XORing P/Q is only implemented in software */ + if (unmap && !(submit->flags & ASYNC_TX_PQ_XOR_DST) && (src_cnt <= dma_maxpq(device, 0) || dma_maxpq(device, DMA_PREP_CONTINUE) > 0) && is_dma_pq_aligned(device, offset, 0, len)) { -- cgit v1.2.3-59-g8ed1b