From d56d000a1f424aa77538bd5aad18b43037ed20cc Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kmo@daterainc.com>
Date: Fri, 9 Aug 2013 21:14:13 -0700
Subject: [PATCH] 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>
---
drivers/md/bcache/bset.c | 6 +++++-
drivers/md/bcache/request.c | 3 ++-
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index 16958704af3b9..e51a739f75141 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -176,10 +176,14 @@ bool bch_ptr_bad(struct btree *b, const struct bkey *k)
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 5878cdb395294..59b3d6df100ba 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -630,7 +630,8 @@ static void bch_cache_read_endio(struct bio *bio, int error)
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;
}
--
2.30.2