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author | Jens Axboe <jens.axboe@oracle.com> | 2008-09-13 20:26:01 +0200 |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2008-10-09 08:56:09 +0200 |
commit | c7c22e4d5c1fdebfac4dba76de7d0338c2b0d832 (patch) | |
tree | ecc3d2517b3471ccc35d4cb4e3b48d4b57205061 /include/linux/elevator.h | |
parent | 18887ad910e56066233a07fd3cfb2fa11338b782 (diff) | |
download | linux-stable-c7c22e4d5c1fdebfac4dba76de7d0338c2b0d832.tar.gz linux-stable-c7c22e4d5c1fdebfac4dba76de7d0338c2b0d832.tar.bz2 linux-stable-c7c22e4d5c1fdebfac4dba76de7d0338c2b0d832.zip |
block: add support for IO CPU affinity
This patch adds support for controlling the IO completion CPU of
either all requests on a queue, or on a per-request basis. We export
a sysfs variable (rq_affinity) which, if set, migrates completions
of requests to the CPU that originally submitted it. A bio helper
(bio_set_completion_cpu()) is also added, so that queuers can ask
for completion on that specific CPU.
In testing, this has been show to cut the system time by as much
as 20-40% on synthetic workloads where CPU affinity is desired.
This requires a little help from the architecture, so it'll only
work as designed for archs that are using the new generic smp
helper infrastructure.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux/elevator.h')
-rw-r--r-- | include/linux/elevator.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 639624b55fbe..bb791c311a56 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -173,15 +173,15 @@ enum { #define rb_entry_rq(node) rb_entry((node), struct request, rb_node) /* - * Hack to reuse the donelist list_head as the fifo time holder while + * Hack to reuse the csd.list list_head as the fifo time holder while * the request is in the io scheduler. Saves an unsigned long in rq. */ -#define rq_fifo_time(rq) ((unsigned long) (rq)->donelist.next) -#define rq_set_fifo_time(rq,exp) ((rq)->donelist.next = (void *) (exp)) +#define rq_fifo_time(rq) ((unsigned long) (rq)->csd.list.next) +#define rq_set_fifo_time(rq,exp) ((rq)->csd.list.next = (void *) (exp)) #define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist) #define rq_fifo_clear(rq) do { \ list_del_init(&(rq)->queuelist); \ - INIT_LIST_HEAD(&(rq)->donelist); \ + INIT_LIST_HEAD(&(rq)->csd.list); \ } while (0) /* |