Commit 14bd75f5 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Andrew Morton
Browse files

mm: factor out a swap_readpage_bdev helper 

Split the block device case from swap_readpage into a separate helper,
following the abstraction for file based swap and frontswap.

Link: https://lkml.kernel.org/r/20230125133436.447864-4-hch@lst.de


Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent a8c1408f

mm/page_io.c

+35 −33
Original line number Diff line number Diff line
@@ -444,44 +444,15 @@ static void swap_readpage_fs(struct page *page, 
		*plug = sio;

}



void swap_readpage(struct page *page, bool synchronous, struct swap_iocb **plug)

static void swap_readpage_bdev(struct page *page, bool synchronous,

		struct swap_info_struct *sis)

{

	struct bio *bio;

	struct swap_info_struct *sis = page_swap_info(page);

	bool workingset = PageWorkingset(page);

	unsigned long pflags;

	bool in_thrashing;



	VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page);

	VM_BUG_ON_PAGE(!PageLocked(page), page);

	VM_BUG_ON_PAGE(PageUptodate(page), page);



	/*

	 * Count submission time as memory stall and delay. When the device

	 * is congested, or the submitting cgroup IO-throttled, submission

	 * can be a significant part of overall IO time.

	 */

	if (workingset) {

		delayacct_thrashing_start(&in_thrashing);

		psi_memstall_enter(&pflags);

	}

	delayacct_swapin_start();



	if (frontswap_load(page) == 0) {

		SetPageUptodate(page);

		unlock_page(page);

		goto out;

	}



	if (data_race(sis->flags & SWP_FS_OPS)) {

		swap_readpage_fs(page, plug);

		goto out;

	}



	if ((sis->flags & SWP_SYNCHRONOUS_IO) &&

	    !bdev_read_page(sis->bdev, swap_page_sector(page), page)) {

		count_vm_event(PSWPIN);

		goto out;

		return;

	}



	bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL);
@@ -508,8 +479,39 @@ void swap_readpage(struct page *page, bool synchronous, struct swap_iocb **plug) 
	}

	__set_current_state(TASK_RUNNING);

	bio_put(bio);

}



void swap_readpage(struct page *page, bool synchronous, struct swap_iocb **plug)

{

	struct swap_info_struct *sis = page_swap_info(page);

	bool workingset = PageWorkingset(page);

	unsigned long pflags;

	bool in_thrashing;



	VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page);

	VM_BUG_ON_PAGE(!PageLocked(page), page);

	VM_BUG_ON_PAGE(PageUptodate(page), page);



	/*

	 * Count submission time as memory stall and delay. When the device

	 * is congested, or the submitting cgroup IO-throttled, submission

	 * can be a significant part of overall IO time.

	 */

	if (workingset) {

		delayacct_thrashing_start(&in_thrashing);

		psi_memstall_enter(&pflags);

	}

	delayacct_swapin_start();



	if (frontswap_load(page) == 0) {

		SetPageUptodate(page);

		unlock_page(page);

	} else if (data_race(sis->flags & SWP_FS_OPS)) {

		swap_readpage_fs(page, plug);

	} else {

		swap_readpage_bdev(page, synchronous, sis);

	}



out:

	if (workingset) {

		delayacct_thrashing_end(&in_thrashing);

		psi_memstall_leave(&pflags);