linux-kernel - [PATCH] x86, MCE: Kill CPU_POST

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Date:	Thu, 22 May 2014 17:30:06 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Peter Zijlstra <peterz@...radead.org>,
	Tony Luck <tony.luck@...el.com>
Cc:	"Srivatsa S. Bhat" <srivatsa.bhat@...ux.vnet.ibm.com>,
	Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
	Jacob Pan <jacob.jun.pan@...ux.intel.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Borislav Petkov <bp@...e.de>, Ingo Molnar <mingo@...nel.org>,
	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	"ego@...ux.vnet.ibm.com" <ego@...ux.vnet.ibm.com>,
	Oleg Nesterov <oleg@...hat.com>
Subject: [PATCH] x86, MCE: Kill CPU_POST_DEAD

On Thu, May 22, 2014 at 02:32:51PM +0200, Peter Zijlstra wrote:
> So I think we can reduce it to just the one rwsem (with recursion) if we
> shoot CPU_POST_DEAD in the head.

Here's the first bullet. Stressing my box here with Steve's hotplug
script seems to work fine.

Tony, any objections?

---
From: Borislav Petkov <bp@...e.de>
Date: Thu, 22 May 2014 16:40:54 +0200
Subject: [PATCH] x86, MCE: Kill CPU_POST_DEAD

In conjunction with cleaning up CPU hotplug, we want to get rid of
CPU_POST_DEAD. Kill this instance here and rediscover CMCI banks at the
end of CPU_DEAD.

Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/kernel/cpu/mcheck/mce.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 68317c80de7f..ee35d621815b 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -2391,6 +2391,7 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 			threshold_cpu_callback(action, cpu);
 		mce_device_remove(cpu);
 		mce_intel_hcpu_update(cpu);
+		cmci_rediscover();
 		break;
 	case CPU_DOWN_PREPARE:
 		smp_call_function_single(cpu, mce_disable_cpu, &action, 1);
@@ -2402,11 +2403,6 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 		break;
 	}
 
-	if (action == CPU_POST_DEAD) {
-		/* intentionally ignoring frozen here */
-		cmci_rediscover();
-	}
-
 	return NOTIFY_OK;
 }
 
-- 
1.9.0

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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