Unverified Commit b6753fb2 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!14332 mm: avoid unconditional one-tick sleep when swapcache_prepare fails 

Merge Pull Request from: @ci-robot 
 
PR sync from: Jinjiang Tu <tujinjiang@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/GK5XZSVIJZVYOV4DXX4OGSAV3FUXI6MB/ 
 
https://gitee.com/openeuler/kernel/issues/IB7294 
 
Link:https://gitee.com/openeuler/kernel/pulls/14332

 

Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarZhang Peng <zhangpeng362@huawei.com>
parents 6b7bfb89 30ee4dc6

mm/memory.c

+13 −2
Original line number Diff line number Diff line
@@ -3963,6 +3963,8 @@ static vm_fault_t handle_pte_marker(struct vm_fault *vmf) 
	return VM_FAULT_SIGBUS;

}



static DECLARE_WAIT_QUEUE_HEAD(swapcache_wq);



/*

 * We enter with non-exclusive mmap_lock (to exclude vma changes,

 * but allow concurrent faults), and pte mapped but not yet locked.
@@ -3975,6 +3977,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) 
{

	struct vm_area_struct *vma = vmf->vma;

	struct folio *swapcache, *folio = NULL;

	DECLARE_WAITQUEUE(wait, current);

	struct page *page;

	struct swap_info_struct *si = NULL;

	rmap_t rmap_flags = RMAP_NONE;
@@ -4064,7 +4067,9 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) 
			 */

			if (swapcache_prepare(entry, 1)) {

				/* Relax a bit to prevent rapid repeated page faults */

				add_wait_queue(&swapcache_wq, &wait);

				schedule_timeout_uninterruptible(1);

				remove_wait_queue(&swapcache_wq, &wait);

				goto out;

			}

			need_clear_cache = true;
@@ -4368,8 +4373,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) 
		pte_unmap_unlock(vmf->pte, vmf->ptl);

out:

	/* Clear the swap cache pin for direct swapin after PTL unlock */

	if (need_clear_cache)

	if (need_clear_cache) {

		swapcache_clear(si, entry, 1);

		if (waitqueue_active(&swapcache_wq))

			wake_up(&swapcache_wq);

	}

	if (si)

		put_swap_device(si);

	return ret;
@@ -4384,8 +4392,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) 
		folio_unlock(swapcache);

		folio_put(swapcache);

	}

	if (need_clear_cache)

	if (need_clear_cache) {

		swapcache_clear(si, entry, 1);

		if (waitqueue_active(&swapcache_wq))

			wake_up(&swapcache_wq);

	}

	if (si)

		put_swap_device(si);

	return ret;