Messages in this thread Patch in this message | | | From | Vivek Goyal <> | Subject | [PATCH 15/16] blkio: Drop the reference to queue once the task changes cgroup | Date | Thu, 12 Nov 2009 18:32:35 -0500 |
| |
o If a task changes cgroup, drop reference to the cfqq associated with io context and set cfqq pointer stored in ioc to NULL so that upon next request arrival we will allocate a new queue in new group.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- block/cfq-iosched.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 files changed, 39 insertions(+), 0 deletions(-)
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 3f7a350..34f029c 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -2648,6 +2648,41 @@ static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, cfqq->pid = pid; } +#ifdef CONFIG_CFQ_GROUP_IOSCHED +static void changed_cgroup(struct io_context *ioc, struct cfq_io_context *cic) +{ + struct cfq_queue *sync_cfqq = cic_to_cfqq(cic, 1); + struct cfq_data *cfqd = cic->key; + unsigned long flags; + struct request_queue *q; + + if (unlikely(!cfqd)) + return; + + q = cfqd->queue; + + spin_lock_irqsave(q->queue_lock, flags); + + if (sync_cfqq) { + /* + * Drop reference to sync queue. A new sync queue will be + * assigned in new group upon arrival of a fresh request. + */ + cfq_log_cfqq(cfqd, sync_cfqq, "changed cgroup"); + cic_set_cfqq(cic, NULL, 1); + cfq_put_queue(sync_cfqq); + } + + spin_unlock_irqrestore(q->queue_lock, flags); +} + +static void cfq_ioc_set_cgroup(struct io_context *ioc) +{ + call_for_each_cic(ioc, changed_cgroup); + ioc->cgroup_changed = 0; +} +#endif /* CONFIG_CFQ_GROUP_IOSCHED */ + static struct cfq_queue * cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, gfp_t gfp_mask) @@ -2880,6 +2915,10 @@ out: if (unlikely(ioc->ioprio_changed)) cfq_ioc_set_ioprio(ioc); +#ifdef CONFIG_CFQ_GROUP_IOSCHED + if (unlikely(ioc->cgroup_changed)) + cfq_ioc_set_cgroup(ioc); +#endif return cic; err_free: cfq_cic_free(cic); -- 1.6.2.5
| |