diff options
author | Eric W. Biederman <ebiederm@xmission.com> | 2006-01-11 16:43:12 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-11 22:04:50 -0500 |
commit | 6e3fbee5f11a8135109b08bfcbc05a29eb4eabe8 (patch) | |
tree | 2a37bbf126d3312ae2a6a0285ea8c2620f58cc39 /arch/i386 | |
parent | 329d400f47ddfe8ff599823d739c5c5565da3207 (diff) |
[PATCH] i386/x86-64: Don't IPI to offline cpus on shutdown
So why are we calling smp_send_stop from machine_halt?
We don't.
Looking more closely at the bug report the problem here
is that halt -p is called which triggers not a halt but
an attempt to power off.
machine_power_off calls machine_shutdown which calls smp_send_stop.
If pm_power_off is set we should never make it out machine_power_off
to the call of do_exit. So pm_power_off must not be set in this case.
When pm_power_off is not set we expect machine_power_off to devolve
into machine_halt.
So how do we fix this?
Playing too much with smp_send_stop is dangerous because it
must also be safe to be called from panic.
It looks like the obviously correct fix is to only call
machine_shutdown when pm_power_off is defined. Doing
that will make Andi's assumption about not scheduling
true and generally simplify what must be supported.
This turns machine_power_off into a noop like machine_halt
when pm_power_off is not defined.
If the expected behavior is that sys_reboot(LINUX_REBOOT_CMD_POWER_OFF)
becomes sys_reboot(LINUX_REBOOT_CMD_HALT) if pm_power_off is NULL
this is not quite a comprehensive fix as we pass a different parameter
to the reboot notifier and we set system_state to a different value
before calling device_shutdown().
Unfortunately any fix more comprehensive I can think of is not
obviously correct. The core problem is that there is no architecture
independent way to detect if machine_power will become a noop, without
calling it.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386')
-rw-r--r-- | arch/i386/kernel/reboot.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/i386/kernel/reboot.c b/arch/i386/kernel/reboot.c index 2fa5803a759d..d207242976d3 100644 --- a/arch/i386/kernel/reboot.c +++ b/arch/i386/kernel/reboot.c | |||
@@ -12,6 +12,7 @@ | |||
12 | #include <linux/efi.h> | 12 | #include <linux/efi.h> |
13 | #include <linux/dmi.h> | 13 | #include <linux/dmi.h> |
14 | #include <linux/ctype.h> | 14 | #include <linux/ctype.h> |
15 | #include <linux/pm.h> | ||
15 | #include <asm/uaccess.h> | 16 | #include <asm/uaccess.h> |
16 | #include <asm/apic.h> | 17 | #include <asm/apic.h> |
17 | #include <asm/desc.h> | 18 | #include <asm/desc.h> |
@@ -355,10 +356,10 @@ void machine_halt(void) | |||
355 | 356 | ||
356 | void machine_power_off(void) | 357 | void machine_power_off(void) |
357 | { | 358 | { |
358 | machine_shutdown(); | 359 | if (pm_power_off) { |
359 | 360 | machine_shutdown(); | |
360 | if (pm_power_off) | ||
361 | pm_power_off(); | 361 | pm_power_off(); |
362 | } | ||
362 | } | 363 | } |
363 | 364 | ||
364 | 365 | ||