Add fix for IPI badness during shutdown, fwd from Ashok Raj and akpm.

Fixes bug: http://bugzilla.kernel.org/show_bug.cgi?id=6077

diff --git a/queue/i386-x86-64-don-t-ipi-to-offline-cpus-on-shutdown.patch b/queue/i386-x86-64-don-t-ipi-to-offline-cpus-on-shutdown.patch
new file mode 100644 (file)
index 0000000..91ec254
--- /dev/null
+++ b/queue/i386-x86-64-don-t-ipi-to-offline-cpus-on-shutdown.patch
@@ -0,0 +1,109 @@
+From stable-bounces@linux.kernel.org  Wed Feb 15 15:55:47 2006
+Date: Wed, 15 Feb 2006 15:51:31 -0800
+From: Andrew Morton <akpm@osdl.org>
+To: stable@kernel.org
+Cc: Ashok Raj <ashok.raj@intel.com>
+Subject: [PATCH] i386/x86-64: Don't IPI to offline cpus on shutdown
+
+From: Eric W. Biederman <ebiederm@xmission.com>
+
+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>
+Signed-off-by: Chris Wright <chrisw@sous-sol.org>
+---
+
+ arch/i386/kernel/reboot.c   |    7 ++++---
+ 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 2fa5803..d207242 100644
+--- linux-2.6.15.4.orig/arch/i386/kernel/reboot.c
++++ linux-2.6.15.4/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();
++      }
+ }
+ 
+ 
+--- linux-2.6.15.4.orig/arch/x86_64/kernel/reboot.c
++++ linux-2.6.15.4/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();
++      }
+ }
+ 

diff --git a/queue/series b/queue/series
index a4a48e5add4c74a9d3bb36ced7c63ce46b815068..e61a6fc2173c4335741e72c3a1bb71fa84202898 100644 (file)
--- a/queue/series
+++ b/queue/series
@@ -7,3 +7,4 @@ hugetlbfs-mmap-enomem-failure.patch
 reiserfs-disable-automatic-enabling-of-reiserfs-inode-attributes.patch
 revert-skb_copy_datagram_iovec-recursion-elimination.patch
 address-autoconfiguration-does-not-work-after-device-down-up-cycle.patch
+i386-x86-64-don-t-ipi-to-offline-cpus-on-shutdown.patch