From 87192a2a49c475cf322cb143e0fa63b0102d8567 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 12 Jan 2012 17:20:34 -0800 Subject: vfs: cache request_queue in struct block_device 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 Acked-by: Jeff Moyer Cc: Jens Axboe Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/block_dev.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs') diff --git a/fs/block_dev.c b/fs/block_dev.c index afe74dda632..0e575d1304b 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1139,6 +1139,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) 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; @@ -1159,6 +1160,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) 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); put_disk(disk); @@ -1232,6 +1234,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) 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); -- cgit v1.2.3