raid5-ppl: partial parity calculation optimization

In case of read-modify-write, partial partity is the same as the result
of ops_run_prexor5(), so we can just copy sh->dev[pd_idx].page into
sh->ppl_page instead of calculating it again.

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
This commit is contained in:
Artur Paszkiewicz 2017-04-04 13:13:58 +02:00 committed by Shaohua Li
parent 845b9e229f
commit ae1713e296
2 changed files with 13 additions and 13 deletions

View file

@ -153,7 +153,7 @@ ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
int disks = sh->disks;
struct page **xor_srcs = flex_array_get(percpu->scribble, 0);
struct page **srcs = flex_array_get(percpu->scribble, 0);
int count = 0, pd_idx = sh->pd_idx, i;
struct async_submit_ctl submit;
@ -166,18 +166,18 @@ ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
* differently.
*/
if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
/* rmw: xor old data and parity from updated disks */
for (i = disks; i--;) {
struct r5dev *dev = &sh->dev[i];
if (test_bit(R5_Wantdrain, &dev->flags) || i == pd_idx)
xor_srcs[count++] = dev->page;
}
/*
* rmw: xor old data and parity from updated disks
* This is calculated earlier by ops_run_prexor5() so just copy
* the parity dev page.
*/
srcs[count++] = sh->dev[pd_idx].page;
} else if (sh->reconstruct_state == reconstruct_state_drain_run) {
/* rcw: xor data from all not updated disks */
for (i = disks; i--;) {
struct r5dev *dev = &sh->dev[i];
if (test_bit(R5_UPTODATE, &dev->flags))
xor_srcs[count++] = dev->page;
srcs[count++] = dev->page;
}
} else {
return tx;
@ -188,10 +188,10 @@ ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
+ sizeof(struct page *) * (sh->disks + 2));
if (count == 1)
tx = async_memcpy(sh->ppl_page, xor_srcs[0], 0, 0, PAGE_SIZE,
tx = async_memcpy(sh->ppl_page, srcs[0], 0, 0, PAGE_SIZE,
&submit);
else
tx = async_xor(sh->ppl_page, xor_srcs, 0, count, PAGE_SIZE,
tx = async_xor(sh->ppl_page, srcs, 0, count, PAGE_SIZE,
&submit);
return tx;

View file

@ -2079,9 +2079,6 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
async_tx_ack(tx);
}
if (test_bit(STRIPE_OP_PARTIAL_PARITY, &ops_request))
tx = ops_run_partial_parity(sh, percpu, tx);
if (test_bit(STRIPE_OP_PREXOR, &ops_request)) {
if (level < 6)
tx = ops_run_prexor5(sh, percpu, tx);
@ -2089,6 +2086,9 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
tx = ops_run_prexor6(sh, percpu, tx);
}
if (test_bit(STRIPE_OP_PARTIAL_PARITY, &ops_request))
tx = ops_run_partial_parity(sh, percpu, tx);
if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
tx = ops_run_biodrain(sh, tx);
overlap_clear++;