From 22e2c507c301c3dbbcf91b4948b88f78842ee6c9 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 27 Jun 2005 10:55:12 +0200 Subject: [PATCH] Update cfq io scheduler to time sliced design This updates the CFQ io scheduler to the new time sliced design (cfq v3). It provides full process fairness, while giving excellent aggregate system throughput even for many competing processes. It supports io priorities, either inherited from the cpu nice value or set directly with the ioprio_get/set syscalls. The latter closely mimic set/getpriority. This import is based on my latest from -mm. Signed-off-by: Jens Axboe Signed-off-by: Linus Torvalds --- include/linux/bio.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux/bio.h') diff --git a/include/linux/bio.h b/include/linux/bio.h index 038022763f0..36ef29fa0d8 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -22,6 +22,7 @@ #include #include +#include /* Platforms may set this to teach the BIO layer about IOMMU hardware. */ #include @@ -149,6 +150,19 @@ struct bio { #define BIO_RW_FAILFAST 3 #define BIO_RW_SYNC 4 +/* + * upper 16 bits of bi_rw define the io priority of this bio + */ +#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS) +#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT) +#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio)) + +#define bio_set_prio(bio, prio) do { \ + WARN_ON(prio >= (1 << IOPRIO_BITS)); \ + (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \ + (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \ +} while (0) + /* * various member access, note that bio_data should of course not be used * on highmem page vectors -- cgit v1.2.3