| Message ID | 1626275195-215652-2-git-send-email-john.garry@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | blk-mq: Reduce static requests memory footprint for shared sbitmap | expand |
On Wed, Jul 14, 2021 at 11:06:27PM +0800, John Garry wrote: > The original code in commit 24d2f90309b23 ("blk-mq: split out tag > initialization, support shared tags") would check tags->rqs is non-NULL and > then dereference tags->rqs[]. > > Then in commit 2af8cbe30531 ("blk-mq: split tag ->rqs[] into two"), we > started to dereference tags->static_rqs[], but continued to check non-NULL > tags->rqs. > > Check tags->static_rqs as non-NULL instead, which is more logical. > > Signed-off-by: John Garry <john.garry@huawei.com> > --- > block/blk-mq.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 2c4ac51e54eb..ae28f470893c 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -2348,7 +2348,7 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, > { > struct page *page; > > - if (tags->rqs && set->ops->exit_request) { > + if (tags->static_rqs && set->ops->exit_request) { Yeah, it is reasonable to check ->static_rqs since both ->init_request() and ->exit_request() operate on request from ->static_rqs[]: Reviewed-by: Ming Lei <ming.lei@redhat.com>
diff --git a/block/blk-mq.c b/block/blk-mq.c index 2c4ac51e54eb..ae28f470893c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2348,7 +2348,7 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, { struct page *page; - if (tags->rqs && set->ops->exit_request) { + if (tags->static_rqs && set->ops->exit_request) { int i; for (i = 0; i < tags->nr_tags; i++) {
The original code in commit 24d2f90309b23 ("blk-mq: split out tag initialization, support shared tags") would check tags->rqs is non-NULL and then dereference tags->rqs[]. Then in commit 2af8cbe30531 ("blk-mq: split tag ->rqs[] into two"), we started to dereference tags->static_rqs[], but continued to check non-NULL tags->rqs. Check tags->static_rqs as non-NULL instead, which is more logical. Signed-off-by: John Garry <john.garry@huawei.com> --- block/blk-mq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)