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/bset.c b/drivers/md/bcache/bset.c
index 1695870..e51a739 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -176,10 +176,14 @@
bch_ptr_invalid(b, k))
return true;
- for (i = 0; i < KEY_PTRS(k); i++) {
+ for (i = 0; i < KEY_PTRS(k); i++)
if (!ptr_available(b->c, k, i))
return true;
+ if (!expensive_debug_checks(b->c) && KEY_DIRTY(k))
+ return false;
+
+ for (i = 0; i < KEY_PTRS(k); i++) {
g = PTR_BUCKET(b->c, k, i);
stale = ptr_stale(b->c, k, i);
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;
}