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Message-ID: <20071112173803.GD5560@alberich.amd.com>
Date: Mon, 12 Nov 2007 18:38:03 +0100
From: "Andreas Herrmann" <andreas.herrmann3@....com>
To: "Andrew Morton" <akpm@...ux-foundation.org>
cc: "Akinobu Mita" <akinobu.mita@...il.com>, ak@...e.de,
tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
linux-kernel@...r.kernel.org
Subject: [PATCH] x86: don't call mce_create_device on CPU_UP_PREPARE
On Fri, Nov 09, 2007 at 12:16:34PM -0800, Andrew Morton wrote:
> Andreas, could you please review and preferably runtime-test this new
> version?
Reviewed and tested.
Akinobu's changes are necessary as well.
Test was ok.
> Assuming that all goes well could one of you please prepare a final patch
> with a complete changelog?
Attached is a new patch with a "combined changelog".
Patch is against v2.6.24-rc2-247-g6e800af.
Regards,
Andreas
--
x86: don't call mce_create_device on CPU_UP_PREPARE
Fix regression introduced with d435d862baca3e25e5eec236762a43251b1e7ffc
("cpu hotplug: mce: fix cpu hotplug error handling").
A CPU which was not brought up during boot (using maxcpus and additional_cpus
parameters) couldn't be onlined anymore. For such a CPU it seemed that MCE
was not supported during CPU_UP_PREPARE-time which caused mce_cpu_callback
to return NOTIFY_BAD to notifier_call_chain.
To fix this we:
- call mce_create_device for CPU_ONLINE event (instead of CPU_UP_PREPARE),
- avoid mce_remove_device() for the CPU that is not correctly initialized
by mce_create_device() failure,
- make mce_cpu_callback always return NOTIFY_OK for CPU_ONLINE event.
Because CPU_ONLINE callback return value is always ignored.
[akinobu.mita@...il.com: avoid mce_remove_device() for not initialized device]
[akinobu.mita@...il.com: make mce_cpu_callback always return NOTIFY_OK]
Signed-off-by: Akinobu Mita <akinobu.mita@...il.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@....com>
---
arch/x86/kernel/cpu/mcheck/mce_64.c | 18 +++++++++++-------
1 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/cpu/mcheck/mce_64.c b/arch/x86/kernel/cpu/mcheck/mce_64.c
index b9f802e..447b351 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_64.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_64.c
@@ -802,6 +802,8 @@ static struct sysdev_attribute *mce_attributes[] = {
NULL
};
+static cpumask_t mce_device_initialized = CPU_MASK_NONE;
+
/* Per cpu sysdev init. All of the cpus still share the same ctl bank */
static __cpuinit int mce_create_device(unsigned int cpu)
{
@@ -825,6 +827,7 @@ static __cpuinit int mce_create_device(unsigned int cpu)
if (err)
goto error;
}
+ cpu_set(cpu, mce_device_initialized);
return 0;
error:
@@ -841,10 +844,14 @@ static void mce_remove_device(unsigned int cpu)
{
int i;
+ if (!cpu_isset(cpu, mce_device_initialized))
+ return;
+
for (i = 0; mce_attributes[i]; i++)
sysdev_remove_file(&per_cpu(device_mce,cpu),
mce_attributes[i]);
sysdev_unregister(&per_cpu(device_mce,cpu));
+ cpu_clear(cpu, mce_device_initialized);
}
/* Get notified when a cpu comes on/off. Be hotplug friendly. */
@@ -852,21 +859,18 @@ static int
mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
- int err = 0;
switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- err = mce_create_device(cpu);
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ mce_create_device(cpu);
break;
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
mce_remove_device(cpu);
break;
}
- return err ? NOTIFY_BAD : NOTIFY_OK;
+ return NOTIFY_OK;
}
static struct notifier_block mce_cpu_notifier = {
--
1.5.3.4
-
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