From e61c90188b9956edae1105eef361d8981a352fcd Mon Sep 17 00:00:00 2001 From: "Chen, Kenneth W" Date: Wed, 13 Dec 2006 00:34:36 -0800 Subject: [PATCH] optimize o_direct on block devices Implement block device specific .direct_IO method instead of going through generic direct_io_worker for block device. direct_io_worker() is fairly complex because it needs to handle O_DIRECT on file system, where it needs to perform block allocation, hole detection, extents file on write, and tons of other corner cases. The end result is that it takes tons of CPU time to submit an I/O. For block device, the block allocation is much simpler and a tight triple loop can be written to iterate each iovec and each page within the iovec in order to construct/prepare bio structure and then subsequently submit it to the block layer. This significantly speeds up O_D on block device. [akpm@osdl.org: small speedup] Signed-off-by: Ken Chen Cc: Christoph Hellwig Cc: Zach Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/bio.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/bio.h') diff --git a/include/linux/bio.h b/include/linux/bio.h index 092dbd0e7658..08daf3272c02 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -309,6 +309,7 @@ extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, gfp_t); extern void bio_set_pages_dirty(struct bio *bio); extern void bio_check_pages_dirty(struct bio *bio); +extern void bio_release_pages(struct bio *bio); extern struct bio *bio_copy_user(struct request_queue *, unsigned long, unsigned int, int); extern int bio_uncopy_user(struct bio *); void zero_fill_bio(struct bio *bio); -- cgit v1.2.3