Commit b467f3ef authored Jun 07, 2020 by Vlastimil Babka Committed by Linus Torvalds Jun 08, 2020

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.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200427180433.7029-4-vbabka@suse.cz


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0a477e1a

Documentation/admin-guide/kernel-parameters.txt

+1 −1

Original line number	Diff line number	Diff line
		@@ -1515,7 +1515,7 @@
		[KNL] Should the hung task detector generate panics.
		Format: <integer>

		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

fs/proc/proc_sysctl.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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" },
		{ }
		};

kernel/hung_task.c

+0 −10

Original line number	Diff line number	Diff line
		@@ -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);

		static int
		hung_task_panic(struct notifier_block this, unsigned long event, void ptr)
		{

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