From 3b18152c327707ae6a2eeba4cfb66457143753bc Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 27 Jun 2005 10:56:24 +0200 Subject: [PATCH] CFQ io scheduler updates - Adjust slice values - Instead of one async queue, one is defined per priority level. This prevents kernel threads (such as reiserfs/x and others) that run at higher io priority from conflicting with others. Previously, it was a coin toss what io prio the async queue got, it was defined by who first set up the queue. - Let a time slice only begin, when the previous slice is completely done. Previously we could be somewhat unfair to a new sync slice, if the previous slice was async and had several ios queued. This might need a little tweaking if throughput suffers a little due to this, allowing perhaps an overlap of a single request or so. - Optimize the calling of kblockd_schedule_work() by doing it only when it is strictly necessary (no requests in driver and work left to do). - Correct sync vs async logic. A 'normal' process can be purely async as well, and a flusher can be purely sync as well. Sync or async is now a property of the class defined and requests pending. Previously writers could be considered sync, when they were really async. - Get rid of the bit fields in cfqq and crq, use flags instead. - Various other cleanups and fixes Signed-off-by: Jens Axboe Signed-off-by: Linus Torvalds --- include/linux/ioprio.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h index 7811300d88ee..8a453a0b5e4b 100644 --- a/include/linux/ioprio.h +++ b/include/linux/ioprio.h @@ -12,6 +12,7 @@ #define IOPRIO_PRIO_CLASS(mask) ((mask) >> IOPRIO_CLASS_SHIFT) #define IOPRIO_PRIO_DATA(mask) ((mask) & IOPRIO_PRIO_MASK) +#define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | data) #define ioprio_valid(mask) (IOPRIO_PRIO_CLASS((mask)) != IOPRIO_CLASS_NONE) -- cgit v1.2.2