bcache: Performance fix for when journal entry is full
We were unnecessarily waiting on a journal write to complete when we just needed
to start a journal write and start setting up the next one.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 29cccc5..ad68728 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -673,6 +673,7 @@
{
size_t sectors;
struct closure cl;
+ bool wait = false;
closure_init_stack(&cl);
@@ -689,9 +690,12 @@
PAGE_SECTORS << JSET_BITS))
return w;
- /* XXX: tracepoint */
+ if (wait)
+ closure_wait(&c->journal.wait, &cl);
+
if (!journal_full(&c->journal)) {
- trace_bcache_journal_entry_full(c);
+ if (wait)
+ trace_bcache_journal_entry_full(c);
/*
* XXX: If we were inserting so many keys that they
@@ -701,12 +705,11 @@
*/
BUG_ON(!w->data->keys);
- closure_wait(&w->wait, &cl);
journal_try_write(c); /* unlocks */
} else {
- trace_bcache_journal_full(c);
+ if (wait)
+ trace_bcache_journal_full(c);
- closure_wait(&c->journal.wait, &cl);
journal_reclaim(c);
spin_unlock(&c->journal.lock);
@@ -715,6 +718,7 @@
closure_sync(&cl);
spin_lock(&c->journal.lock);
+ wait = true;
}
}