From 598971bfbdfdc8701337dc1636c7919c44699914 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 19 Mar 2012 15:10:58 -0700 Subject: 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 Cc: Vivek Goyal Signed-off-by: Jens Axboe --- include/linux/ioprio.h | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-) (limited to 'include/linux/ioprio.h') 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; -- cgit v1.2.3