diff options
author | Tejun Heo <tj@kernel.org> | 2012-03-19 15:10:58 -0700 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2012-03-20 12:47:47 +0100 |
commit | 598971bfbdfdc8701337dc1636c7919c44699914 (patch) | |
tree | 3de33d5059ce3a0cf77a9735804335f9264b7c08 /include/linux/ioprio.h | |
parent | abede6da27d9bd62ea9512830c83e32b3ee1104c (diff) |
cfq: don't use icq_get_changed()
cfq caches the associated cfqq's for a given cic. The cache needs to
be flushed if the cic's ioprio or blkcg has changed. It is currently
done by requiring the changing action to set the respective
ICQ_*_CHANGED bit in the icq and testing it from cfq_set_request(),
which involves iterating through all the affected icqs.
All cfq wants to know is whether ioprio and/or blkcg have changed
since the last flush and can be easily achieved by just remembering
the current ioprio and blkcg ID in cic.
This patch adds cic->{ioprio|blkcg_id}, updates all ioprio users to
use the remembered value instead, and updates cfq_set_request() path
such that, instead of using icq_get_changed(), the current values are
compared against the remembered ones and trigger appropriate flush
action if not. Condition tests are moved inside both _changed
functions which are now named check_ioprio_changed() and
check_blkcg_changed().
ioprio.h::task_ioprio*() can't be used anymore and replaced with
open-coded IOPRIO_CLASS_NONE case in cfq_async_queue_prio().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux/ioprio.h')
-rw-r--r-- | include/linux/ioprio.h | 22 |
1 files changed, 5 insertions, 17 deletions
diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h index 76dad4808847..beb9ce1c2c23 100644 --- a/include/linux/ioprio.h +++ b/include/linux/ioprio.h @@ -42,26 +42,14 @@ enum { }; /* - * if process has set io priority explicitly, use that. if not, convert - * the cpu scheduler nice value to an io priority + * Fallback BE priority */ #define IOPRIO_NORM (4) -static inline int task_ioprio(struct io_context *ioc) -{ - if (ioprio_valid(ioc->ioprio)) - return IOPRIO_PRIO_DATA(ioc->ioprio); - - return IOPRIO_NORM; -} - -static inline int task_ioprio_class(struct io_context *ioc) -{ - if (ioprio_valid(ioc->ioprio)) - return IOPRIO_PRIO_CLASS(ioc->ioprio); - - return IOPRIO_CLASS_BE; -} +/* + * if process has set io priority explicitly, use that. if not, convert + * the cpu scheduler nice value to an io priority + */ static inline int task_nice_ioprio(struct task_struct *task) { return (task_nice(task) + 20) / 5; |