Re: [PATCH] blkcg: stop iteration early if root_rl is the only request list
On 2012-10-22 03:15, Jun'ichi Nomura wrote: > __blk_queue_next_rl() finds next request list based on blkg_list > while skipping root_blkg in the list. > OTOH, root_rl is special as it may exist even without root_blkg. > > Though the later part of the function handles such a case correctly, > exiting early is good for readability of the code. Applied to for-linus, thanks. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] blkcg: stop iteration early if root_rl is the only request list
On Mon, Oct 22, 2012 at 10:15:37AM +0900, Jun'ichi Nomura wrote:
> __blk_queue_next_rl() finds next request list based on blkg_list
> while skipping root_blkg in the list.
> OTOH, root_rl is special as it may exist even without root_blkg.
>
> Though the later part of the function handles such a case correctly,
> exiting early is good for readability of the code.
>
Thanks for the patch Junichi. This one looks good to me.
Acked-by: Vivek Goyal
Vivek
> Signed-off-by: Jun'ichi Nomura
> Cc: Vivek Goyal
> Cc: Tejun Heo
> Cc: Jens Axboe
> ---
> block/blk-cgroup.c |3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index 54f35d1..a31e678 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -333,6 +333,9 @@ struct request_list *__blk_queue_next_rl(struct
> request_list *rl,
>*/
> if (rl == >root_rl) {
> ent = >blkg_list;
> + /* There are no more block groups, hence no request lists */
> + if (list_empty(ent))
> + return NULL;
> } else {
> blkg = container_of(rl, struct blkcg_gq, rl);
> ent = >q_node;
--
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Re: [PATCH] blkcg: stop iteration early if root_rl is the only request list
On Mon, Oct 22, 2012 at 10:15:37AM +0900, Jun'ichi Nomura wrote:
__blk_queue_next_rl() finds next request list based on blkg_list
while skipping root_blkg in the list.
OTOH, root_rl is special as it may exist even without root_blkg.
Though the later part of the function handles such a case correctly,
exiting early is good for readability of the code.
Thanks for the patch Junichi. This one looks good to me.
Acked-by: Vivek Goyal vgo...@redhat.com
Vivek
Signed-off-by: Jun'ichi Nomura j-nom...@ce.jp.nec.com
Cc: Vivek Goyal vgo...@redhat.com
Cc: Tejun Heo t...@kernel.org
Cc: Jens Axboe ax...@kernel.dk
---
block/blk-cgroup.c |3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 54f35d1..a31e678 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -333,6 +333,9 @@ struct request_list *__blk_queue_next_rl(struct
request_list *rl,
*/
if (rl == q-root_rl) {
ent = q-blkg_list;
+ /* There are no more block groups, hence no request lists */
+ if (list_empty(ent))
+ return NULL;
} else {
blkg = container_of(rl, struct blkcg_gq, rl);
ent = blkg-q_node;
--
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Re: [PATCH] blkcg: stop iteration early if root_rl is the only request list
On 2012-10-22 03:15, Jun'ichi Nomura wrote: __blk_queue_next_rl() finds next request list based on blkg_list while skipping root_blkg in the list. OTOH, root_rl is special as it may exist even without root_blkg. Though the later part of the function handles such a case correctly, exiting early is good for readability of the code. Applied to for-linus, thanks. -- Jens Axboe -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] blkcg: stop iteration early if root_rl is the only request list
__blk_queue_next_rl() finds next request list based on blkg_list
while skipping root_blkg in the list.
OTOH, root_rl is special as it may exist even without root_blkg.
Though the later part of the function handles such a case correctly,
exiting early is good for readability of the code.
Signed-off-by: Jun'ichi Nomura
Cc: Vivek Goyal
Cc: Tejun Heo
Cc: Jens Axboe
---
block/blk-cgroup.c |3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 54f35d1..a31e678 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -333,6 +333,9 @@ struct request_list *__blk_queue_next_rl(struct
request_list *rl,
*/
if (rl == >root_rl) {
ent = >blkg_list;
+ /* There are no more block groups, hence no request lists */
+ if (list_empty(ent))
+ return NULL;
} else {
blkg = container_of(rl, struct blkcg_gq, rl);
ent = >q_node;
--
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH] blkcg: stop iteration early if root_rl is the only request list
__blk_queue_next_rl() finds next request list based on blkg_list
while skipping root_blkg in the list.
OTOH, root_rl is special as it may exist even without root_blkg.
Though the later part of the function handles such a case correctly,
exiting early is good for readability of the code.
Signed-off-by: Jun'ichi Nomura j-nom...@ce.jp.nec.com
Cc: Vivek Goyal vgo...@redhat.com
Cc: Tejun Heo t...@kernel.org
Cc: Jens Axboe ax...@kernel.dk
---
block/blk-cgroup.c |3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 54f35d1..a31e678 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -333,6 +333,9 @@ struct request_list *__blk_queue_next_rl(struct
request_list *rl,
*/
if (rl == q-root_rl) {
ent = q-blkg_list;
+ /* There are no more block groups, hence no request lists */
+ if (list_empty(ent))
+ return NULL;
} else {
blkg = container_of(rl, struct blkcg_gq, rl);
ent = blkg-q_node;
--
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