From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f50.google.com (mail-ej1-f50.google.com [209.85.218.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF043381B9 for ; Mon, 5 Aug 2024 13:51:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722865916; cv=none; b=A6GJ0uEFZFWKh39MiT0AiGGJWBots4TKB/DQhXeqSfAPaJ4sXBmXhN3WHhcy/QInsXg4c3htmzwc5LDIahU1S0djfuCHP3FCfVo9gwoXxNCETh3rFN2zFzYYnyWpboFoO95ZSIuz9S11Gs0S7ulP2SwKrJqhzmjRqFkV6HB/zlQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722865916; c=relaxed/simple; bh=/AQHrtR5h5O7jPYa96FCXxXdYahXu4b6b7nQxDZkFvI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OSREBDxtmksbqHrJy43stlHfElyGBwFA22kGz7AFKwCL4IVepyGxr69AvdYwyvkvbGMs+ay6pjT9vupGWF3JwvRUQO4IqgwwhdKaSdtX8DFDp1/e9BtSCAwaHR9ISwbjRxqNAq6IKWw7Uc0i9KSd5aQvbnVM+HMjshpKrnE9zIA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=Q4iKV2Zh; arc=none smtp.client-ip=209.85.218.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="Q4iKV2Zh" Received: by mail-ej1-f50.google.com with SMTP id a640c23a62f3a-a7ad02501c3so402267866b.2 for ; Mon, 05 Aug 2024 06:51:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1722865913; x=1723470713; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=24KhsaR7Lyt0pADalfMlyDC/kBHqcMJwqIFxV24o+xI=; b=Q4iKV2ZhcuvMcFHmLjKWEZzpHC8j7pofGci6A/BeV1naAQDisioB9O9LCwadk3FsjG LZDwFZrnTS3Xf4GYx0pTfuH1G3TyVPP4bEX7hfYHyM5BqDtZ4N3cfUSpyX09IJL/rcwW V1X7rEyqMP64Ia0xW4GydB/35RiNExh5AX16OCIFrgto1PBv/EgeQD7a7E2HyXtWNpxq gZFdVEohUMFg1eBFoURVVCfELN7oRbTXQveK9bMG311Tkr9XQoLAhue0gYbXXxKTpctL 5VMr+FV3pXMmcGTCRJxSTPO9zx14thsZM/bESVU/q3zKDZIJW8k9vPrtaVhaC3X4G51S 9Tvg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722865913; x=1723470713; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=24KhsaR7Lyt0pADalfMlyDC/kBHqcMJwqIFxV24o+xI=; b=Mn5fSnoJsbnb0jhM/uBJpcgdBA1Usjz4xHo/wUUKEhqAKAwY9K/lTWC7JrE3pix6Ix olpVE27ZxNar52pKwS66VH+syaMmEn/+1pY0WP+oLr2r1NQczsUOAcsdIc01PdMtdD9P EVZVAAy53arcVl7Ncay2Y3nXskxd8CV9qgSNVO1JsLRL02Opp+0zSx9Zwncwi/Yv0HRc S4sBieXMAgBA93uvb+ucsw+bM9X+BIbKZgdMeqi0vIsD5Ss756gp/hZkH7RUFSbplT1r VGQsbvl6v5bNa+8R2nXqaU1+lGOCJEdR6IqWJJwT8Dk3hlmoXX1mqnLTzmr3uvD+ocpV C0GA== X-Forwarded-Encrypted: i=1; AJvYcCX05ei63XUYD2DYhpKfGU1V+KmnRm5SXmXUpcRnjHuMBbK5hWrsm4v9dl6B5gi3gnvtoxmiarVprO/DMMitRkVDPpPjBg9FGBHvji+g X-Gm-Message-State: AOJu0YzyS0Mf+RZiJjdeBKQtFHEtOnxLNCFIHzGxFvFnzbmrflIy6nqV ja7ExeoFHxEGB+cULQhRxrzqVaUjhWaoEhfB94oWpVb2xTJ6R8Zp/2tCga3gMOI= X-Google-Smtp-Source: AGHT+IFFM/8blKXit81pVr2Mv0h8jRP3TcYzMugO9+xBcfDh4uEgqi7RuNIHOiT7MH3GWierzUp2Cw== X-Received: by 2002:a17:907:3f0b:b0:a7a:a2b7:93ff with SMTP id a640c23a62f3a-a7dc51bd262mr893412466b.57.1722865913037; Mon, 05 Aug 2024 06:51:53 -0700 (PDT) Received: from pathway.suse.cz ([176.114.240.50]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a7dc9bc3d2asm457320966b.45.2024.08.05.06.51.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Aug 2024 06:51:52 -0700 (PDT) Date: Mon, 5 Aug 2024 15:51:51 +0200 From: Petr Mladek To: takakura@valinux.co.jp Cc: 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, linux-kernel@vger.kernel.org, nishimura@valinux.co.jp, taka@valinux.co.jp Subject: Re: [PATCH v2 2/2] Allow cpu backtraces to be written into ringbuffer during panic Message-ID: References: <20240803080444.221427-1-takakura@valinux.co.jp> <20240803081649.224627-1-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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240803081649.224627-1-takakura@valinux.co.jp> On Sat 2024-08-03 17:16:49, takakura@valinux.co.jp wrote: > From: Ryo Takakura > > commit 779dbc2e78d7 ("printk: Avoid non-panic CPUs writing > to ringbuffer") disabled non-panic CPUs to further write messages to > ringbuffer after panicked. > > Since the commit, non-panicked CPU's are not allowed to write to > ring buffer after panicked and CPU backtrace which is triggered > after panicked to sample non-panicked CPUs' backtrace no longer > serves its function as it has nothing to print. > > Fix the issue by allowing non-panicked CPUs to write into ringbuffer > while CPU backtrace is in flight. > > Fixes: 779dbc2e78d7 ("printk: Avoid non-panic CPUs writing to ringbuffer") > Signed-off-by: Ryo Takakura Reviewed-by: Petr Mladek Best Regards, Petr