The patch titled Subject: fs/proc: fix softlockup in __read_vmcore has been added to the -mm mm-nonmm-unstable branch. Its filename is fs-proc-fix-softlockup-in-__read_vmcore.patch

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

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

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------------------------------------------------------ From: Rik van Riel riel@surriel.com Subject: fs/proc: fix softlockup in __read_vmcore Date: Tue, 7 May 2024 09:18:58 -0400

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 ---

fs/proc/vmcore.c | 2 ++ 1 file changed, 2 insertions(+)

--- a/fs/proc/vmcore.c~fs-proc-fix-softlockup-in-__read_vmcore +++ a/fs/proc/vmcore.c @@ -383,6 +383,8 @@ static ssize_t __read_vmcore(struct iov_ /* leave now if filled buffer already */ if (!iov_iter_count(iter)) return acc; + + cond_resched(); }

list_for_each_entry(m, &vmcore_list, list) { _

Patches currently in -mm which might be from riel@surriel.com are

fs-proc-fix-softlockup-in-__read_vmcore.patch