From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752342AbeBZDXu (ORCPT ); Sun, 25 Feb 2018 22:23:50 -0500 Received: from g4t3426.houston.hpe.com ([15.241.140.75]:40488 "EHLO g4t3426.houston.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752149AbeBZDWg (ORCPT ); Sun, 25 Feb 2018 22:22:36 -0500 From: Jerry Hoemann To: wim@linux-watchdog.org, linux@roeck-us.net Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, rwright@hpe.com, maurice.a.saldivar@hpe.com, mingo@kernel.org, marcus.folkesson@gmail.com, Jerry Hoemann Subject: [PATCH v5 6/9] watchdog/hpwdt: remove allow_kdump module parameter. Date: Sun, 25 Feb 2018 20:22:24 -0700 Message-Id: <20180226032227.14615-7-jerry.hoemann@hpe.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180226032227.14615-1-jerry.hoemann@hpe.com> References: <20180226032227.14615-1-jerry.hoemann@hpe.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The intent of this parameter is unclear and it sets up a race between the reset of the system by ASR and crashdump. The length of time between receipt of the pretimeout NMI and the ASR reset of the system is fixed by hardware. Turning the parameter off doesn't necessairly prevent a crash dump. Also, having the ASR reset occur while the system is crash dumping doesn't imply that the dump was hung given the short duration between the NMI and the reset. This parameter is not a substitute for having a architected watchdog crashdump hang detection paridigm. Signed-off-by: Jerry Hoemann --- drivers/watchdog/hpwdt.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c index 171d5033d7b5..68e84a212d00 100644 --- a/drivers/watchdog/hpwdt.c +++ b/drivers/watchdog/hpwdt.c @@ -36,9 +36,6 @@ static bool ilo5; static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */ static unsigned int reload; /* the computed soft_margin */ static bool nowayout = WATCHDOG_NOWAYOUT; -#ifdef CONFIG_HPWDT_NMI_DECODING -static unsigned int allow_kdump = 1; -#endif static void __iomem *pci_mem_addr; /* the PCI-memory address */ static unsigned long __iomem *hpwdt_nmistat; @@ -124,8 +121,7 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs) if (ilo5 && ulReason == NMI_UNKNOWN && mynmi) return NMI_DONE; - if (allow_kdump) - hpwdt_stop(); + hpwdt_stop(); hex_byte_pack(panic_msg, mynmi); nmi_panic(regs, panic_msg); @@ -186,9 +182,8 @@ static int hpwdt_init_nmi_decoding(struct pci_dev *dev) goto error2; dev_info(&dev->dev, - "HPE Watchdog Timer Driver: NMI decoding initialized" - ", allow kernel dump: %s (default = 1/ON)\n", - (allow_kdump == 0) ? "OFF" : "ON"); + "HPE Watchdog Timer Driver: NMI decoding initialized\n"); + return 0; error2: @@ -322,9 +317,4 @@ module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); -#ifdef CONFIG_HPWDT_NMI_DECODING -module_param(allow_kdump, int, 0); -MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs"); -#endif /* CONFIG_HPWDT_NMI_DECODING */ - module_pci_driver(hpwdt_driver); -- 2.13.6