From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 09/54] kernel/hung_task convert hung_task_panic boot parameter to sysctl Date: Sun, 07 Jun 2020 21:40:31 -0700 Message-ID: <20200608044031.nggr6xU6_%akpm@linux-foundation.org> References: <20200607212615.b050e41fac139a1e16fe00bd@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:35894 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726929AbgFHEke (ORCPT ); Mon, 8 Jun 2020 00:40:34 -0400 In-Reply-To: <20200607212615.b050e41fac139a1e16fe00bd@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: adobriyan@gmail.com, akpm@linux-foundation.org, christian.brauner@ubuntu.com, ebiederm@xmission.com, gpiccoli@canonical.com, gregkh@linuxfoundation.org, ivan.teterevkov@nutanix.com, keescook@chromium.org, linux-mm@kvack.org, mcgrof@kernel.org, mhiramat@kernel.org, mhocko@kernel.org, mhocko@suse.com, mm-commits@vger.kernel.org, rientjes@google.com, tglx@linutronix.de, torvalds@linux-foundation.org, vbabka@suse.cz, willy@infradead.org, yzaikin@google.com From: Vlastimil Babka Subject: kernel/hung_task convert hung_task_panic boot parameter to sysctl We can now handle sysctl parameters on kernel command line and have infrastructure to convert legacy command line options that duplicate sysctl to become a sysctl alias. This patch converts the hung_task_panic parameter. Note that the sysctl handler is more strict and allows only 0 and 1, while the legacy parameter allowed any non-zero value. But there is little reason anyone would not be using 1. Link: http://lkml.kernel.org/r/20200427180433.7029-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka Reviewed-by: Kees Cook Acked-by: Michal Hocko Cc: Alexey Dobriyan Cc: Christian Brauner Cc: David Rientjes Cc: "Eric W . Biederman" Cc: Greg Kroah-Hartman Cc: "Guilherme G . Piccoli" Cc: Iurii Zaikin Cc: Ivan Teterevkov Cc: Luis Chamberlain Cc: Masami Hiramatsu Cc: Matthew Wilcox Cc: Michal Hocko Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- Documentation/admin-guide/kernel-parameters.txt | 2 +- fs/proc/proc_sysctl.c | 1 + kernel/hung_task.c | 10 ---------- 3 files changed, 2 insertions(+), 11 deletions(-) --- a/Documentation/admin-guide/kernel-parameters.txt~kernel-hung_task-convert-hung_task_panic-boot-parameter-to-sysctl +++ a/Documentation/admin-guide/kernel-parameters.txt @@ -1515,7 +1515,7 @@ [KNL] Should the hung task detector generate panics. Format: - A nonzero value instructs the kernel to panic when a + A value of 1 instructs the kernel to panic when a hung task is detected. The default value is controlled by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time option. The value selected by this boot parameter can --- a/fs/proc/proc_sysctl.c~kernel-hung_task-convert-hung_task_panic-boot-parameter-to-sysctl +++ a/fs/proc/proc_sysctl.c @@ -1721,6 +1721,7 @@ struct sysctl_alias { */ static const struct sysctl_alias sysctl_aliases[] = { {"numa_zonelist_order", "vm.numa_zonelist_order" }, + {"hung_task_panic", "kernel.hung_task_panic" }, { } }; --- a/kernel/hung_task.c~kernel-hung_task-convert-hung_task_panic-boot-parameter-to-sysctl +++ a/kernel/hung_task.c @@ -63,16 +63,6 @@ static struct task_struct *watchdog_task unsigned int __read_mostly sysctl_hung_task_panic = CONFIG_BOOTPARAM_HUNG_TASK_PANIC_VALUE; -static int __init hung_task_panic_setup(char *str) -{ - int rc = kstrtouint(str, 0, &sysctl_hung_task_panic); - - if (rc) - return rc; - return 1; -} -__setup("hung_task_panic=", hung_task_panic_setup);