]> git.karo-electronics.de Git - linux-beck.git/commit
reboot: rigrate shutdown/reboot to boot cpu
authorRobin Holt <holt@sgi.com>
Wed, 12 Jun 2013 21:04:37 +0000 (14:04 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 12 Jun 2013 23:29:44 +0000 (16:29 -0700)
commitcf7df378aa4ff7da3a44769b7ff6e9eef1a9f3db
treec9d93d55f6ff87eb47621d2c47d9ca2bff5f3a9a
parent16e53dbf10a2d7e228709a7286310e629ede5e45
reboot: rigrate shutdown/reboot to boot cpu

We recently noticed that reboot of a 1024 cpu machine takes approx 16
minutes of just stopping the cpus.  The slowdown was tracked to commit
f96972f2dc63 ("kernel/sys.c: call disable_nonboot_cpus() in
kernel_restart()").

The current implementation does all the work of hot removing the cpus
before halting the system.  We are switching to just migrating to the
boot cpu and then continuing with shutdown/reboot.

This also has the effect of not breaking x86's command line parameter
for specifying the reboot cpu.  Note, this code was shamelessly copied
from arch/x86/kernel/reboot.c with bits removed pertaining to the
reboot_cpu command line parameter.

Signed-off-by: Robin Holt <holt@sgi.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/sys.c