From 7eaceaccab5f40bbfda044629a6298616aeaed50 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 10 Mar 2011 08:52:07 +0100 Subject: block: remove per-queue plugging Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe --- mm/swapfile.c | 37 ------------------------------------- 1 file changed, 37 deletions(-) (limited to 'mm/swapfile.c') diff --git a/mm/swapfile.c b/mm/swapfile.c index 07a458d72fa8..7ceea78ceb20 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -94,39 +94,6 @@ __try_to_reclaim_swap(struct swap_info_struct *si, unsigned long offset) return ret; } -/* - * We need this because the bdev->unplug_fn can sleep and we cannot - * hold swap_lock while calling the unplug_fn. And swap_lock - * cannot be turned into a mutex. - */ -static DECLARE_RWSEM(swap_unplug_sem); - -void swap_unplug_io_fn(struct backing_dev_info *unused_bdi, struct page *page) -{ - swp_entry_t entry; - - down_read(&swap_unplug_sem); - entry.val = page_private(page); - if (PageSwapCache(page)) { - struct block_device *bdev = swap_info[swp_type(entry)]->bdev; - struct backing_dev_info *bdi; - - /* - * If the page is removed from swapcache from under us (with a - * racy try_to_unuse/swapoff) we need an additional reference - * count to avoid reading garbage from page_private(page) above. - * If the WARN_ON triggers during a swapoff it maybe the race - * condition and it's harmless. However if it triggers without - * swapoff it signals a problem. - */ - WARN_ON(page_count(page) <= 1); - - bdi = bdev->bd_inode->i_mapping->backing_dev_info; - blk_run_backing_dev(bdi, page); - } - up_read(&swap_unplug_sem); -} - /* * swapon tell device that all the old swap contents can be discarded, * to allow the swap device to optimize its wear-levelling. @@ -1643,10 +1610,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) goto out_dput; } - /* wait for any unplug function to finish */ - down_write(&swap_unplug_sem); - up_write(&swap_unplug_sem); - destroy_swap_extents(p); if (p->flags & SWP_CONTINUED) free_swap_count_continuations(p); -- cgit v1.2.3