From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pf1-x442.google.com ([2607:f8b0:4864:20::442]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kfEGz-0008Si-86 for kexec@lists.infradead.org; Wed, 18 Nov 2020 03:36:46 +0000 Received: by mail-pf1-x442.google.com with SMTP id b63so517430pfg.12 for ; Tue, 17 Nov 2020 19:36:43 -0800 (PST) From: Pingfan Liu Subject: [PATCH 0/3] use soft lockup to detect irq flood Date: Wed, 18 Nov 2020 11:36:15 +0800 Message-Id: <1605670578-23681-1-git-send-email-kernelfans@gmail.com> In-Reply-To: <87tuueftou.fsf@nanos.tec.linutronix.de> References: <87tuueftou.fsf@nanos.tec.linutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: linux-kernel@vger.kernel.org Cc: Petr Mladek , "Peter Zijlstra (Intel)" , "Guilherme G. Piccoli" , kexec@lists.infradead.org, Pingfan Liu , Jisheng Zhang , Thomas Gleixner , Andrew Morton , Vlastimil Babka The chipset's pins are often multi-used because greedy usage compares to a finite pin number. This requests a carefully configuration in firmware or OS. If not, it may contribute to most of irq flood cases, which appears as a soft lockup issue on Linux. Strictly speaking, soft lockup and irq flood are different things to overcome. And it is helpful to make users aware of that situation for prime time. This series shows the irq statistics when soft lockup. The statistics can be used to evaluate the possibility of irq flood and as a rough evaluated input to the kernel parameter "irqstorm_limit" in [1]. It is not easy to find a common way to work around irq flood, which may be raised by different root cause. To now, it is still a open question. Thomas and Guilherme suggested patches to suppress the odd irq in different situation. [1].[2] [1]: https://lore.kernel.org/lkml/87tuueftou.fsf@nanos.tec.linutronix.de/ [2]: https://lore.kernel.org/linux-pci/20181018183721.27467-1-gpiccoli@canonical.com/ Cc: Thomas Gleixner Cc: Jisheng Zhang Cc: "Peter Zijlstra (Intel)" Cc: Vlastimil Babka Cc: Andrew Morton Cc: "Guilherme G. Piccoli" Cc: Petr Mladek Cc: kexec@lists.infradead.org To: linux-kernel@vger.kernel.org Pingfan Liu (3): x86/irq: account the unused irq kernel/watchdog: make watchdog_touch_ts more accurate by using nanosecond kernel/watchdog: use soft lockup to detect irq flood arch/x86/kernel/irq.c | 1 + include/linux/kernel_stat.h | 1 + kernel/watchdog.c | 37 ++++++++++++++++++++++++++----------- 3 files changed, 28 insertions(+), 11 deletions(-) -- 2.7.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec