From: Rik van Riel riel@surriel.com

stable inclusion from stable-v4.19.317 commit 7bdf1d550ddfcd9ab797087421f77b7aceddc8a7 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAJKLA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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 Signed-off-by: Xiaomeng Zhang zhangxiaomeng13@huawei.com --- fs/proc/vmcore.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index f5dfedc01552..cd384a1ebef5 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -359,6 +359,8 @@ static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos, /* leave now if filled buffer already */ if (buflen == 0) return acc; + + cond_resched(); }

list_for_each_entry(m, &vmcore_list, list) {