The patch titled
vfs: cache request_queue in struct block_device
has been added to the -mm tree. Its filename is
vfs-cache-request_queue-in-struct-block_device.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: vfs: cache request_queue in struct block_device
From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
This makes it possible to get from the inode to the request_queue with one
less cache miss. Used in followon optimization.
The livetime of the pointer is the same as the gendisk.
This assumes that the queue will always stay the same in the gendisk while
it's visible to block_devices. I think that's safe correct?
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Acked-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/block_dev.c | 3 +++
include/linux/fs.h | 2 ++
2 files changed, 5 insertions(+)
diff -puN fs/block_dev.c~vfs-cache-request_queue-in-struct-block_device fs/block_dev.c
--- a/fs/block_dev.c~vfs-cache-request_queue-in-struct-block_device
+++ a/fs/block_dev.c
@@ -1115,6 +1115,7 @@ static int __blkdev_get(struct block_dev
mutex_lock_nested(&bdev->bd_mutex, for_part);
if (!bdev->bd_openers) {
bdev->bd_disk = disk;
+ bdev->bd_queue = disk->queue;
bdev->bd_contains = bdev;
if (!partno) {
struct backing_dev_info *bdi;
@@ -1135,6 +1136,7 @@ static int __blkdev_get(struct block_dev
disk_put_part(bdev->bd_part);
bdev->bd_part = NULL;
bdev->bd_disk = NULL;
+ bdev->bd_queue = NULL;
mutex_unlock(&bdev->bd_mutex);
disk_unblock_events(disk);
module_put(disk->fops->owner);
@@ -1208,6 +1210,7 @@ static int __blkdev_get(struct block_dev
disk_put_part(bdev->bd_part);
bdev->bd_disk = NULL;
bdev->bd_part = NULL;
+ bdev->bd_queue = NULL;
bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info);
if (bdev != bdev->bd_contains)
__blkdev_put(bdev->bd_contains, mode, 1);
diff -puN include/linux/fs.h~vfs-cache-request_queue-in-struct-block_device include/linux/fs.h
--- a/include/linux/fs.h~vfs-cache-request_queue-in-struct-block_device
+++ a/include/linux/fs.h
@@ -657,6 +657,7 @@ struct address_space {
* must be enforced here for CRIS, to let the least significant bit
* of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
*/
+struct request_queue;
struct block_device {
dev_t bd_dev; /* not a kdev_t - it's a search key */
@@ -679,6 +680,7 @@ struct block_device {
unsigned bd_part_count;
int bd_invalidated;
struct gendisk * bd_disk;
+ struct request_queue * bd_queue;
struct list_head bd_list;
/*
* Private data. You must have bd_claim'ed the block_device
_
Patches currently in -mm which might be from ak@xxxxxxxxxxxxxxx are
linux-next.patch
dio-separate-fields-only-used-in-the-submission-path-from-struct-dio.patch
dio-separate-fields-only-used-in-the-submission-path-from-struct-dio-checkpatch-fixes.patch
dio-fix-a-wrong-comment.patch
dio-rearrange-fields-in-dio-dio_submit-to-avoid-holes.patch
dio-use-a-slab-cache-for-struct-dio.patch
dio-separate-map_bh-from-dio-v2.patch
dio-inline-the-complete-submission-path-v2.patch
dio-inline-the-complete-submission-path-v2-checkpatch-fixes.patch
dio-merge-direct_io_walker-into-__blockdev_direct_io.patch
dio-merge-direct_io_walker-into-__blockdev_direct_io-checkpatch-fixes.patch
dio-remove-unnecessary-dio-argument-from-dio_pages_present.patch
dio-remove-unused-dio-parameter-from-dio_bio_add_page.patch
vfs-cache-request_queue-in-struct-block_device.patch
dio-optimize-cache-misses-in-the-submission-path-v2.patch
dio-optimize-cache-misses-in-the-submission-path-v2-checkpatch-fixes.patch
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