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Wed, 20 Aug 2025 02:17:49 -0700 (PDT) Received: from localhost.localdomain ([114.242.33.243]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-76e7ccfa8d1sm4847120b3a.0.2025.08.20.02.17.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Aug 2025 02:17:49 -0700 (PDT) From: Jinchao Wang To: pmladek@suse.com, akpm@linux-foundation.org, Feng Tang , John Ogness , Jinchao Wang , Joel Granados , Nam Cao , Sravan Kumar Gundu Cc: linux-kernel@vger.kernel.org Subject: [PATCH 5/9] panic: use panic_try_start() in vpanic() Date: Wed, 20 Aug 2025 17:14:50 +0800 Message-ID: <20250820091702.512524-6-wangjinchao600@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250820091702.512524-5-wangjinchao600@gmail.com> References: <20250820091702.512524-1-wangjinchao600@gmail.com> <20250820091702.512524-2-wangjinchao600@gmail.com> <20250820091702.512524-3-wangjinchao600@gmail.com> <20250820091702.512524-4-wangjinchao600@gmail.com> <20250820091702.512524-5-wangjinchao600@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit vpanic() had open-coded logic to claim panic_cpu with atomic_try_cmpxchg. This is already handled by panic_try_start(). Switch to panic_try_start() and use panic_on_other_cpu() for the fallback path. This removes duplicate code and makes panic handling consistent across functions. Signed-off-by: Jinchao Wang --- kernel/panic.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/panic.c b/kernel/panic.c index cd86d37d124c..5266e195f5ac 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -415,7 +415,6 @@ void vpanic(const char *fmt, va_list args) static char buf[1024]; long i, i_next = 0, len; int state = 0; - int old_cpu, this_cpu; bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers; if (panic_on_warn) { @@ -452,13 +451,10 @@ void vpanic(const char *fmt, va_list args) * `old_cpu == this_cpu' means we came from nmi_panic() which sets * panic_cpu to this CPU. In this case, this is also the 1st CPU. */ - old_cpu = PANIC_CPU_INVALID; - this_cpu = raw_smp_processor_id(); - /* atomic_try_cmpxchg updates old_cpu on failure */ - if (atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu)) { + if (panic_try_start()) { /* go ahead */ - } else if (old_cpu != this_cpu) + } else if (panic_on_other_cpu()) panic_smp_self_stop(); console_verbose(); -- 2.43.0