bcache: Don't touch bucket gen for dirty ptrs
Unnecessary since a bucket that has dirty pointers pointing to it can
never be invalidated - and skipping it is a measurable performance
boost, since the bucket gen will usually be a cache miss.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 5878cdb..59b3d6d 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -630,7 +630,8 @@
if (error)
s->iop.error = error;
- else if (ptr_stale(s->iop.c, &b->key, 0)) {
+ else if (!KEY_DIRTY(&b->key) &&
+ ptr_stale(s->iop.c, &b->key, 0)) {
atomic_long_inc(&s->iop.c->cache_read_races);
s->iop.error = -EINTR;
}