+ mm-add-cond_resched-in-swapin_walk_pmd_entry.patch added to mm-unstable branch

+ mm-add-cond_resched-in-swapin_walk_pmd_entry.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: add cond_resched() in swapin_walk_pmd_entry()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-add-cond_resched-in-swapin_walk_pmd_entry.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-cond_resched-in-swapin_walk_pmd_entry.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: mm: add cond_resched() in swapin_walk_pmd_entry()
Date: Mon, 5 Dec 2022 22:03:27 +0800

When handling MADV_WILLNEED in madvise(), a soflockup may occurr in
swapin_walk_pmd_entry() if swapping in lots of memory on a slow device. 
Add a cond_resched() to avoid the possible softlockup.

Link: https://lkml.kernel.org/r/20221205140327.72304-1-wangkefeng.wang@huawei.com
Fixes: 1998cc048901 ("mm: make madvise(MADV_WILLNEED) support swap file prefetch")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/madvise.c |    1 +
 1 file changed, 1 insertion(+)

--- a/mm/madvise.c~mm-add-cond_resched-in-swapin_walk_pmd_entry
+++ a/mm/madvise.c
@@ -223,6 +223,7 @@ static int swapin_walk_pmd_entry(pmd_t *
 			put_page(page);
 	}
 	swap_read_unplug(splug);
+	cond_resched();
 
 	return 0;
 }
_

Patches currently in -mm which might be from wangkefeng.wang@huawei.com are

mm-add-cond_resched-in-swapin_walk_pmd_entry.patch