From 3bc217ffe6774e7971d6a7ce6350ce806ebab044 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 1 Feb 2008 11:34:49 +0100 Subject: [PATCH] block: kill swap_io_context() It blindly copies everything in the io_context, including the lock. That doesn't work so well for either lock ordering or lockdep. There seems zero point in swapping io contexts on a request to request merge, so the best point of action is to just remove it. Signed-off-by: Jens Axboe --- block/as-iosched.c | 14 -------------- block/blk-ioc.c | 9 --------- include/linux/blkdev.h | 1 - 3 files changed, 24 deletions(-) diff --git a/block/as-iosched.c b/block/as-iosched.c index 612d64096300..8c3946787dbb 100644 --- a/block/as-iosched.c +++ b/block/as-iosched.c @@ -1268,22 +1268,8 @@ static void as_merged_requests(struct request_queue *q, struct request *req, */ if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) { if (time_before(rq_fifo_time(next), rq_fifo_time(req))) { - struct io_context *rioc = RQ_IOC(req); - struct io_context *nioc = RQ_IOC(next); - list_move(&req->queuelist, &next->queuelist); rq_set_fifo_time(req, rq_fifo_time(next)); - /* - * Don't copy here but swap, because when anext is - * removed below, it must contain the unused context - */ - if (rioc != nioc) { - double_spin_lock(&rioc->lock, &nioc->lock, - rioc < nioc); - swap_io_context(&rioc, &nioc); - double_spin_unlock(&rioc->lock, &nioc->lock, - rioc < nioc); - } } } diff --git a/block/blk-ioc.c b/block/blk-ioc.c index 6d1675508eb5..80245dc30c75 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -176,15 +176,6 @@ void copy_io_context(struct io_context **pdst, struct io_context **psrc) } EXPORT_SYMBOL(copy_io_context); -void swap_io_context(struct io_context **ioc1, struct io_context **ioc2) -{ - struct io_context *temp; - temp = *ioc1; - *ioc1 = *ioc2; - *ioc2 = temp; -} -EXPORT_SYMBOL(swap_io_context); - int __init blk_ioc_init(void) { iocontext_cachep = kmem_cache_create("blkdev_ioc", diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index cf170391c474..90392a9d7a9c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -39,7 +39,6 @@ void exit_io_context(void); struct io_context *get_io_context(gfp_t gfp_flags, int node); struct io_context *alloc_io_context(gfp_t gfp_flags, int node); void copy_io_context(struct io_context **pdst, struct io_context **psrc); -void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); struct request; typedef void (rq_end_io_fn)(struct request *, int); -- 2.20.1