lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

block: share request flush fields with elevator_private

Browse Source 
Flush requests are never put on the IO scheduler.  Convert request
structure's elevator_private* into an array and have the flush fields
share a union with it.

Reclaim the space lost in 'struct request' by moving 'completion_data'
back in the union with 'rb_node'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Mike Snitzer
2011-02-11 11:08:00 +01:00
committed by Jens Axboe
parent 9d5a4e946c
commit c186794dbb
3 changed files with 22 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
include/linux/blkdev.h
View File

@ -99,25 +99,26 @@ struct request {
/*
* The rb_node is only used inside the io scheduler, requests
* are pruned when moved to the dispatch queue. So let the
* flush fields share space with the rb_node.
* completion_data share space with the rb_node.
*/
union {
struct rb_node rb_node; /* sort/lookup */
struct {
unsigned int seq;
struct list_head list;
} flush;
void *completion_data;
};
void *completion_data;
/*
* Three pointers are available for the IO schedulers, if they need
* more they have to dynamically allocate it.
* more they have to dynamically allocate it. Flush requests are
* never put on the IO scheduler. So let the flush fields share
* space with the three elevator_private pointers.
*/
void *elevator_private;
void *elevator_private2;
void *elevator_private3;
union {
void *elevator_private[3];
struct {
unsigned int seq;
struct list_head list;
} flush;
};
struct gendisk *rq_disk;
unsigned long start_time;