Re: [PATCH 18/19] io-controller: Debug hierarchical IO scheduling

Vivek Goyal
2009-06-19T14:09:29Z

On Fri, Jun 19, 2009 at 02:26:06PM +0800, Gui Jianfeng wrote:
> Vivek Goyal wrote:
> ...
> > +static inline void bfq_account_for_entity_addition(struct io_entity *entity)
> > +{
> > + struct io_group *iog = io_entity_to_iog(entity);
> > +
> > + if (iog) {
> > + struct elv_fq_data *efqd;
> > + char path[128];
> > +
> > + /*
> > + * Keep track of how many times a group has been removed
> > + * from active tree because it did not have any active
> > + * backlogged ioq under it
> > + */
> > + iog->queue++;
> > + iog->queue_start = jiffies;
> > +
> > + /* Log group addition event */
> > + rcu_read_lock();
> > + efqd = rcu_dereference(iog->key);
> > + if (efqd) {
> > + io_group_path(iog, path, sizeof(path));
> > + elv_log(efqd, "add group=%s weight=%ld", path,
> > + iog->entity.weight);
>
> Since cgroup path is already cached, why not use it. :)
>

Thanks Gui. Queued for next posting.

Vivek

> Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
> ---
> block/elevator-fq.c | 12 ++++--------
> 1 files changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/block/elevator-fq.c b/block/elevator-fq.c
> index bfa79c9..1a397c3 100644
> --- a/block/elevator-fq.c
> +++ b/block/elevator-fq.c
> @@ -183,7 +183,6 @@ static inline void bfq_account_for_entity_addition(struct io_entity *entity)
>
> if (iog) {
> struct elv_fq_data *efqd;
> - char path[128];
>
> /*
> * Keep track of how many times a group has been removed
> @@ -197,9 +196,8 @@ static inline void bfq_account_for_entity_addition(struct io_entity *entity)
> rcu_read_lock();
> efqd = rcu_dereference(iog->key);
> if (efqd) {
> - io_group_path(iog, path, sizeof(path));
> - elv_log(efqd, "add group=%s weight=%ld", path,
> - iog->entity.weight);
> + elv_log(efqd, "add group=%s weight=%ld", iog->path,
> + iog->entity.weight);
> }
> rcu_read_unlock();
> }
> @@ -215,7 +213,6 @@ static inline void bfq_account_for_entity_deletion(struct io_entity *entity)
>
> if (iog) {
> struct elv_fq_data *efqd;
> - char path[128];
>
> iog->dequeue++;
> /* Keep a track of how long group was on active tree */
> @@ -227,9 +224,8 @@ static inline void bfq_account_for_entity_deletion(struct io_entity *entity)
> rcu_read_lock();
> efqd = rcu_dereference(iog->key);
> if (efqd) {
> - io_group_path(iog, path, sizeof(path));
> - elv_log(efqd, "del group=%s weight=%ld", path,
> - iog->entity.weight);
> + elv_log(efqd, "del group=%s weight=%ld", iog->path,
> + iog->entity.weight);
> }
> rcu_read_unlock();
> }
> --
> 1.5.4.rc3
>
>