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| author | Eric W. Biederman <ebiederm@xmission.com> | 2006-01-11 22:43:12 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-11 19:04:50 -0800 |
| commit | 6e3fbee5f11a8135109b08bfcbc05a29eb4eabe8 (patch) | |
| tree | 2a37bbf126d3312ae2a6a0285ea8c2620f58cc39 /arch | |
| parent | 329d400f47ddfe8ff599823d739c5c5565da3207 (diff) | |
| download | linux-6e3fbee5f11a8135109b08bfcbc05a29eb4eabe8.tar.bz2 | |
[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')
| -rw-r--r-- | arch/i386/kernel/reboot.c | 7 | ||||
| -rw-r--r-- | arch/x86_64/kernel/reboot.c | 10 |
2 files changed, 10 insertions, 7 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 @@ #include <linux/efi.h> #include <linux/dmi.h> #include <linux/ctype.h> +#include <linux/pm.h> #include <asm/uaccess.h> #include <asm/apic.h> #include <asm/desc.h> @@ -355,10 +356,10 @@ void machine_halt(void) void machine_power_off(void) { - machine_shutdown(); - - if (pm_power_off) + if (pm_power_off) { + machine_shutdown(); pm_power_off(); + } } diff --git a/arch/x86_64/kernel/reboot.c b/arch/x86_64/kernel/reboot.c index 75235ed2b31b..57117b8beb2b 100644 --- a/arch/x86_64/kernel/reboot.c +++ b/arch/x86_64/kernel/reboot.c @@ -6,6 +6,7 @@ #include <linux/kernel.h> #include <linux/ctype.h> #include <linux/string.h> +#include <linux/pm.h> #include <asm/io.h> #include <asm/kdebug.h> #include <asm/delay.h> @@ -154,10 +155,11 @@ void machine_halt(void) void machine_power_off(void) { - if (!reboot_force) { - machine_shutdown(); - } - if (pm_power_off) + if (pm_power_off) { + if (!reboot_force) { + machine_shutdown(); + } pm_power_off(); + } } |