fs/proc: fix softlockup in __read_vmcore

commit 5cbcb62dddf5346077feb82b7b0c9254222d3445 upstream.

While taking a kernel core dump with makedumpfile on a larger system,
softlockup messages often appear.

While softlockup warnings can be harmless, they can also interfere with
things like RCU freeing memory, which can be problematic when the kdump
kexec image is configured with as little memory as possible.

Avoid the softlockup, and give things like work items and RCU a chance to
do their thing during __read_vmcore by adding a cond_resched.

Link: https://lkml.kernel.org/r/20240507091858.36ff767f@imladris.surriel.com
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit is contained in:

Rik van Riel

2024-05-07 09:18:58 -04:00

committed by

Greg Kroah-Hartman

parent ba04b459ef

commit 518fbd644d

1 changed files with 2 additions and 0 deletions

									
										2

fs/proc/vmcore.c

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				@ -383,6 +383,8 @@ static ssize_t __read_vmcore(struct iov_iter *iter, loff_t *fpos)

						/* leave now if filled buffer already */

						if (!iov_iter_count(iter))

							return acc;

						cond_resched();

					}

					list_for_each_entry(m, &vmcore_list, list) {

fs/proc: fix softlockup in __read_vmcore

2 fs/proc/vmcore.c Unescape Escape View File

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fs/proc/vmcore.c

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