linux-kernel - [PATCH] panic: remove redundant panic-cpu backtrace

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Message-ID: <20250731030314.3818040-1-senozhatsky@chromium.org>
Date: Thu, 31 Jul 2025 12:02:57 +0900
From: Sergey Senozhatsky <senozhatsky@...omium.org>
To: Andrew Morton <akpm@...ux-foundation.org>,
	Petr Mladek <pmladek@...e.com>
Cc: Feng Tang <feng.tang@...ux.alibaba.com>,
	John Ogness <john.ogness@...utronix.de>,
	linux-kernel@...r.kernel.org,
	Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: [PATCH] panic: remove redundant panic-cpu backtrace

SYS_INFO_ALL_CPU_BT sends NMI backtrace request to
all CPUs, which dumps an extra backtrace on panic CPU.
Exclude panic CPU from SYS_INFO_ALL_CPU_BT cpu-mask.

Signed-off-by: Sergey Senozhatsky <senozhatsky@...omium.org>
---
 kernel/panic.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/panic.c b/kernel/panic.c
index 27747cecb1af..c08f2695cf42 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -335,9 +335,11 @@ void check_panic_on_warn(const char *origin)
 static void panic_other_cpus_shutdown(bool crash_kexec)
 {
 	if (panic_print & SYS_INFO_ALL_CPU_BT) {
+		unsigned int this_cpu = raw_smp_processor_id();
+
 		/* Temporary allow non-panic CPUs to write their backtraces. */
 		panic_triggering_all_cpu_backtrace = true;
-		trigger_all_cpu_backtrace();
+		trigger_allbutcpu_cpu_backtrace(this_cpu);
 		panic_triggering_all_cpu_backtrace = false;
 	}
 
-- 
2.50.1.565.gc32cd1483b-goog