linux-kernel - [PATCH] x86, mce: short output of MCE banks ownership information

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Date:	Thu, 29 Oct 2009 12:38:43 +0900
From:	Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>
To:	linux-kernel@...r.kernel.org, x86@...nel.org
CC:	Andi Kleen <ak@...ux.intel.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, Mike Travis <travis@....com>,
	Roland Dreier <rdreier@...co.com>
Subject: [PATCH] x86, mce: short output of MCE banks ownership information

The output of MCE banks ownership information on boot tend to be long on
new processor which has many banks:

  CPU 1 MCA banks SHD:0 SHD:1 CMCI:2 CMCI:3 CMCI:5 SHD:6 SHD:7 SHD:8 SHD:9 SHD:12 SHD:13 SHD:14 SHD:15 SHD:16 SHD:17 SHD:18 SHD:19 SHD:20 SHD:21

This patch changes this message to shorter format, in lower message level
(KERN_INFO -> KERN_DEBUG), and replace "MCA" by "MCE":

  CPU 1 MCE banks map: ssCC PCss ssPP ssss ssss ss

where: s: shared, C: checked by CMCI, P: checked by poll.

(NOTE: This patch still use old format on the output when ownership is
       updated, e.g. a cpu take over the ownership from hot-removed cpu.

  CPU 1 MCE banks map updated: CMCI:6 CMCI:7 CMCI:10 CMCI:11
  CPU 1 MCE banks map: ssCC PCCC ssPP ssCC ssss ss
)

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>
---
 arch/x86/kernel/cpu/mcheck/mce_intel.c |   29 +++++++++++++++++++++++------
 1 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c
index 7c78563..2b4c78b 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_intel.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c
@@ -64,12 +64,25 @@ static void intel_threshold_interrupt(void)
 	mce_notify_irq();
 }
 
+static void print_banks_map(int banks)
+{
+	int i;
+
+	pr_debug("CPU %d MCE banks map:", smp_processor_id());
+	for (i = 0; i < banks; i++) {
+		pr_cont("%s%s", (i % 4) ? "" : " ",
+			test_bit(i, __get_cpu_var(mce_banks_owned)) ? "C" :
+			test_bit(i, __get_cpu_var(mce_poll_banks)) ? "P" : "s");
+	}
+	pr_cont("\n");
+}
+
 static void print_update(char *type, int *hdr, int num)
 {
 	if (*hdr == 0)
-		printk(KERN_INFO "CPU %d MCA banks", smp_processor_id());
+		pr_debug("CPU %d MCE banks map updated:", smp_processor_id());
 	*hdr = 1;
-	printk(KERN_CONT " %s:%d", type, num);
+	pr_cont(" %s:%d", type, num);
 }
 
 /*
@@ -85,6 +98,7 @@ static void cmci_discover(int banks, int boot)
 	int i;
 
 	spin_lock_irqsave(&cmci_discover_lock, flags);
+
 	for (i = 0; i < banks; i++) {
 		u64 val;
 
@@ -95,7 +109,7 @@ static void cmci_discover(int banks, int boot)
 
 		/* Already owned by someone else? */
 		if (val & CMCI_EN) {
-			if (test_and_clear_bit(i, owned) || boot)
+			if (test_and_clear_bit(i, owned) && !boot)
 				print_update("SHD", &hdr, i);
 			__clear_bit(i, __get_cpu_var(mce_poll_banks));
 			continue;
@@ -107,16 +121,19 @@ static void cmci_discover(int banks, int boot)
 
 		/* Did the enable bit stick? -- the bank supports CMCI */
 		if (val & CMCI_EN) {
-			if (!test_and_set_bit(i, owned) || boot)
+			if (!test_and_set_bit(i, owned) && !boot)
 				print_update("CMCI", &hdr, i);
 			__clear_bit(i, __get_cpu_var(mce_poll_banks));
 		} else {
 			WARN_ON(!test_bit(i, __get_cpu_var(mce_poll_banks)));
 		}
 	}
-	spin_unlock_irqrestore(&cmci_discover_lock, flags);
 	if (hdr)
-		printk(KERN_CONT "\n");
+		pr_cont("\n");
+	if (boot || hdr)
+		print_banks_map(banks);
+
+	spin_unlock_irqrestore(&cmci_discover_lock, flags);
 }
 
 /*
-- 
1.6.5.2
--
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