[Devel] [PATCH RHEL7 COMMIT] ploop: push_backup: optimize ploop_pb_put_reported()
Konstantin Khorenko
khorenko at virtuozzo.com
Fri May 20 05:57:47 PDT 2016
The commit is pushed to "branch-rh7-3.10.0-327.18.2.vz7.14.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.18.2.vz7.14.5
------>
commit 0fb4dff848a098b16c93028aed261d4f5aa11a33
Author: Maxim Patlasov <mpatlasov at virtuozzo.com>
Date: Fri May 20 16:57:47 2016 +0400
ploop: push_backup: optimize ploop_pb_put_reported()
To process an extent [clu, clu + len) coming from userspace, let's firstly
find the leftmost preq in the tree matching this interval.
Then, we can iterate to the right by rb_next() until we meet a preq that
doesn't match.
That's it because any preq to the right would have any higher req_cluster,
and hence doesn't match too.
https://jira.sw.ru/browse/PSBM-45000
Signed-off-by: Maxim Patlasov <mpatlasov at virtuozzo.com>
---
drivers/block/ploop/dev.c | 9 +---
drivers/block/ploop/push_backup.c | 107 +++++++++++++++++++++++++-------------
2 files changed, 73 insertions(+), 43 deletions(-)
diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
index f3bb092..15e34e5 100644
--- a/drivers/block/ploop/dev.c
+++ b/drivers/block/ploop/dev.c
@@ -4626,13 +4626,8 @@ static int ploop_push_backup_io_write(struct ploop_device *plo, unsigned long ar
goto io_write_done;
rc = 0;
- for (i = 0; i < ctl->n_extents; i++) {
- cluster_t j;
- for (j = e[i].clu; j < e[i].clu + e[i].len; j++)
- ploop_pb_put_reported(plo->pbd, j, 1);
- /* OPTIMIZE ME LATER: like this:
- * ploop_pb_put_reported(plo->pbd, e[i].clu, e[i].len); */
- }
+ for (i = 0; i < ctl->n_extents; i++)
+ ploop_pb_put_reported(plo->pbd, e[i].clu, e[i].len);
io_write_done:
kfree(e);
diff --git a/drivers/block/ploop/push_backup.c b/drivers/block/ploop/push_backup.c
index ba64468..90172e4 100644
--- a/drivers/block/ploop/push_backup.c
+++ b/drivers/block/ploop/push_backup.c
@@ -329,11 +329,23 @@ static void ploop_pb_add_req_to_reported(struct ploop_pushbackup_desc *pbd,
ploop_pb_add_req_to_tree(preq, &pbd->reported_tree);
}
+static inline bool preq_match(struct ploop_request *preq, cluster_t clu,
+ cluster_t len)
+{
+ return preq &&
+ clu <= preq->req_cluster &&
+ preq->req_cluster < clu + len;
+}
+
+/* returns leftmost preq which req_cluster >= clu */
static struct ploop_request *ploop_pb_get_req_from_tree(struct rb_root *tree,
- cluster_t clu)
+ cluster_t clu, cluster_t len,
+ struct ploop_request **npreq)
{
struct rb_node *n = tree->rb_node;
- struct ploop_request *p;
+ struct ploop_request *p = NULL;
+
+ *npreq = NULL;
while (n) {
p = rb_entry(n, struct ploop_request, reloc_link);
@@ -342,11 +354,31 @@ static struct ploop_request *ploop_pb_get_req_from_tree(struct rb_root *tree,
n = n->rb_left;
else if (clu > p->req_cluster)
n = n->rb_right;
- else {
+ else { /* perfect match */
+ n = rb_next(n);
+ if (n)
+ *npreq = rb_entry(n, struct ploop_request,
+ reloc_link);
rb_erase(&p->reloc_link, tree);
return p;
}
}
+ /* here p is not perfect, but it's closest */
+
+ if (p && p->req_cluster < clu) {
+ n = rb_next(&p->reloc_link);
+ if (n)
+ p = rb_entry(n, struct ploop_request, reloc_link);
+ }
+
+ if (preq_match(p, clu, len)) {
+ n = rb_next(&p->reloc_link);
+ if (n)
+ *npreq = rb_entry(n, struct ploop_request, reloc_link);
+ rb_erase(&p->reloc_link, tree);
+ return p;
+ }
+
return NULL;
}
@@ -393,20 +425,6 @@ ploop_pb_get_first_req_from_reported(struct ploop_pushbackup_desc *pbd)
return ploop_pb_get_first_req_from_tree(&pbd->reported_tree, NULL);
}
-static struct ploop_request *
-ploop_pb_get_req_from_pending(struct ploop_pushbackup_desc *pbd,
- cluster_t clu)
-{
- return ploop_pb_get_req_from_tree(&pbd->pending_tree, clu);
-}
-
-static struct ploop_request *
-ploop_pb_get_req_from_reported(struct ploop_pushbackup_desc *pbd,
- cluster_t clu)
-{
- return ploop_pb_get_req_from_tree(&pbd->reported_tree, clu);
-}
-
int ploop_pb_preq_add_pending(struct ploop_pushbackup_desc *pbd,
struct ploop_request *preq)
{
@@ -552,27 +570,46 @@ get_pending_unlock:
return err;
}
+static void ploop_pb_process_extent(struct rb_root *tree, cluster_t clu,
+ cluster_t len, struct list_head *ready_list,
+ int *n_found)
+{
+ struct ploop_request *preq, *npreq;
+
+ preq = ploop_pb_get_req_from_tree(tree, clu, len, &npreq);
+
+ while (preq) {
+ struct rb_node *n;
+
+ __set_bit(PLOOP_REQ_PUSH_BACKUP, &preq->state);
+ list_add(&preq->list, ready_list);
+
+ if (n_found)
+ (*n_found)++;
+
+ if (!preq_match(npreq, clu, len))
+ break;
+
+ preq = npreq;
+ n = rb_next(&preq->reloc_link);
+ if (n)
+ npreq = rb_entry(n, struct ploop_request, reloc_link);
+ else
+ npreq = NULL;
+ rb_erase(&preq->reloc_link, tree);
+ }
+}
+
void ploop_pb_put_reported(struct ploop_pushbackup_desc *pbd,
cluster_t clu, cluster_t len)
{
- struct ploop_request *preq;
int n_found = 0;
-
- /* OPTIMIZE ME LATER: find leftmost item for [clu, clu+len),
- * then rb_next() while req_cluster < clu+len.
- * Do this firstly for reported, then for pending */
- BUG_ON(len != 1);
+ LIST_HEAD(ready_list);
spin_lock(&pbd->ppb_lock);
- preq = ploop_pb_get_req_from_reported(pbd, clu);
- if (!preq)
- preq = ploop_pb_get_req_from_pending(pbd, clu);
- else
- n_found++;
-
- if (preq)
- __set_bit(PLOOP_REQ_PUSH_BACKUP, &preq->state);
+ ploop_pb_process_extent(&pbd->reported_tree, clu, len, &ready_list, &n_found);
+ ploop_pb_process_extent(&pbd->pending_tree, clu, len, &ready_list, NULL);
/*
* If preq not found above, it's unsolicited report. Then it's
@@ -600,13 +637,11 @@ void ploop_pb_put_reported(struct ploop_pushbackup_desc *pbd,
spin_unlock(&pbd->ppb_lock);
- if (preq) {
- struct ploop_device *plo = preq->plo;
- BUG_ON(preq->req_cluster != clu);
- BUG_ON(plo != pbd->plo);
+ if (!list_empty(&ready_list)) {
+ struct ploop_device *plo = pbd->plo;
spin_lock_irq(&plo->lock);
- list_add_tail(&preq->list, &plo->ready_queue);
+ list_splice(&ready_list, plo->ready_queue.prev);
if (test_bit(PLOOP_S_WAIT_PROCESS, &plo->state))
wake_up_interruptible(&plo->waitq);
spin_unlock_irq(&plo->lock);
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