Move the code that put one idle sh(hot in cache, but happens to be zero referenced) back to active stage to __find_stripe(). Because that's what need to do every time you invoke __find_stripe().
Moving it there avoids duplicate code, as well as makes a bit more sense, IMO, as it tells a whole story now. Signed-off-by: Yuanhan Liu <[email protected]> --- drivers/md/raid5.c | 50 ++++++++++++++++++-------------------------------- 1 file changed, 18 insertions(+), 32 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 77dfd72..e7fa818 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -567,8 +567,25 @@ static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector, pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector); hlist_for_each_entry(sh, stripe_hash(conf, sector), hash) - if (sh->sector == sector && sh->generation == generation) + if (sh->sector == sector && sh->generation == generation) { + if (!atomic_inc_not_zero(&sh->count)) { + spin_lock(&conf->device_lock); + if (!atomic_read(&sh->count)) { + if (!test_bit(STRIPE_HANDLE, &sh->state)) + atomic_inc(&conf->active_stripes); + BUG_ON(list_empty(&sh->lru) && + !test_bit(STRIPE_EXPANDING, &sh->state)); + list_del_init(&sh->lru); + if (sh->group) { + sh->group->stripes_cnt--; + sh->group = NULL; + } + } + atomic_inc(&sh->count); + spin_unlock(&conf->device_lock); + } return sh; + } pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector); return NULL; } @@ -698,21 +715,6 @@ get_active_stripe(struct r5conf *conf, sector_t sector, init_stripe(sh, sector, previous); atomic_inc(&sh->count); } - } else if (!atomic_inc_not_zero(&sh->count)) { - spin_lock(&conf->device_lock); - if (!atomic_read(&sh->count)) { - if (!test_bit(STRIPE_HANDLE, &sh->state)) - atomic_inc(&conf->active_stripes); - BUG_ON(list_empty(&sh->lru) && - !test_bit(STRIPE_EXPANDING, &sh->state)); - list_del_init(&sh->lru); - if (sh->group) { - sh->group->stripes_cnt--; - sh->group = NULL; - } - } - atomic_inc(&sh->count); - spin_unlock(&conf->device_lock); } } while (sh == NULL); @@ -771,22 +773,6 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh hash = stripe_hash_locks_hash(head_sector); spin_lock_irq(conf->hash_locks + hash); head = __find_stripe(conf, head_sector, conf->generation); - if (head && !atomic_inc_not_zero(&head->count)) { - spin_lock(&conf->device_lock); - if (!atomic_read(&head->count)) { - if (!test_bit(STRIPE_HANDLE, &head->state)) - atomic_inc(&conf->active_stripes); - BUG_ON(list_empty(&head->lru) && - !test_bit(STRIPE_EXPANDING, &head->state)); - list_del_init(&head->lru); - if (head->group) { - head->group->stripes_cnt--; - head->group = NULL; - } - } - atomic_inc(&head->count); - spin_unlock(&conf->device_lock); - } spin_unlock_irq(conf->hash_locks + hash); if (!head) -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
