From nobody Tue Feb 10 16:02:12 2026 Received: from mail.valinux.co.jp (mail.valinux.co.jp [210.128.90.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D11617173C for ; Sat, 3 Aug 2024 08:13:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.128.90.3 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722672811; cv=none; b=Cq1GWp6spVnR+tMYKMpG7nOerNbfVJ9jWqn96QfZU8SL8grjDH7PKnSPDTeT3t1UfFfiKO/oHVUCqeFjyq+l9KKRd5DRg5XjRezCg4OKH/Yq6qqEDWoCsWUHtqYvhCg6OLkJaJTp+iS3R8h2I18TjBMEp8Bz3XQ3gkE8RvoEZEw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722672811; c=relaxed/simple; bh=HrxnCbsdaVmoeidDEDy7PQl6RTJyNL5zzHzFva/a3Vg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=VAabTDrGODE01zbVFMNox6NQefHM3DglDFLSCeibjiZnp0MaLOpnzGpIK3KV6uzamqTC+XEBk04XajbmufzWNwbEpZHMfDssPaE2ifQjGJkCHG37E3VFhVuTzvn9a9wfSMM4SqM5KkLbfl7N3fe1GYZ0nsVXE6URDogeb9HVkxI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=valinux.co.jp; spf=pass smtp.mailfrom=valinux.co.jp; arc=none smtp.client-ip=210.128.90.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=valinux.co.jp Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=valinux.co.jp Received: from localhost (localhost [127.0.0.1]) by mail.valinux.co.jp (Postfix) with ESMTP id 05631A9DD3; Sat, 3 Aug 2024 17:13:28 +0900 (JST) X-Virus-Scanned: Debian amavisd-new at valinux.co.jp Received: from mail.valinux.co.jp ([127.0.0.1]) by localhost (mail.valinux.co.jp [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id PKfo01gvh7Qi; Sat, 3 Aug 2024 17:13:27 +0900 (JST) Received: from localhost.localdomain (p10213112-ipngn20001marunouchi.tokyo.ocn.ne.jp [153.220.101.112]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by mail.valinux.co.jp (Postfix) with ESMTPSA id 96278A9D63; Sat, 3 Aug 2024 17:13:27 +0900 (JST) From: takakura@valinux.co.jp To: pmladek@suse.com, rostedt@goodmis.org, john.ogness@linutronix.de, senozhatsky@chromium.org, akpm@linux-foundation.org, bhe@redhat.com, lukas@wunner.de, wangkefeng.wang@huawei.com, ubizjak@gmail.com, feng.tang@intel.com, j.granados@samsung.com, stephen.s.brennan@oracle.com Cc: linux-kernel@vger.kernel.org, nishimura@valinux.co.jp, taka@valinux.co.jp, Ryo Takakura Subject: [PATCH v2 1/2] Handle flushing of CPU backtraces during panic Date: Sat, 3 Aug 2024 17:12:30 +0900 Message-Id: <20240803081230.223512-1-takakura@valinux.co.jp> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240803080444.221427-1-takakura@valinux.co.jp> References: <20240803080444.221427-1-takakura@valinux.co.jp> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Ryo Takakura After panic, non-panicked CPU's has been unable to flush ringbuffer=20 while they can still write into it. This can affect CPU backtrace=20 triggered in panic only able to write into ringbuffer incapable of=20 flushing them. Fix the issue by letting the panicked CPU handle the flushing of=20 ringbuffer right after non-panicked CPUs finished writing their backtraces. Signed-off-by: Ryo Takakura Reviewed-by: John Ogness --- kernel/panic.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/panic.c b/kernel/panic.c index 7e2070925..f94923a63 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -252,8 +252,10 @@ void check_panic_on_warn(const char *origin) */ static void panic_other_cpus_shutdown(bool crash_kexec) { - if (panic_print & PANIC_PRINT_ALL_CPU_BT) + if (panic_print & PANIC_PRINT_ALL_CPU_BT) { trigger_all_cpu_backtrace(); + console_flush_on_panic(CONSOLE_FLUSH_PENDING); + } =20 /* * Note that smp_send_stop() is the usual SMP shutdown function, --=20 2.34.1