From: Jay Lan <jlan@sgi.com>
To: linux-ia64@vger.kernel.org
Subject: [PATCH] Do not call SN_SAL_SET_CPU_NUMBER twice on cpu 0
Date: Mon, 11 Dec 2006 23:39:23 +0000 [thread overview]
Message-ID: <457DEC2B.3060104@sgi.com> (raw)
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This is an SN specific patch.
Architectually, cpu_init is always called twice on cpu 0
and thus resulted in two SN_SAL_SET_CPU_NUMBER calls.
This was harmless in production kernel; however, it can
cause problem on booting up a crashdump kernel at Altix.
Here is the patch that detects the second sn_cpu_init
call and skips the second call to SN_SAL_SET_CPU_NUMBER.
Signed-Off-By: Jay Lan <jlan@sgi.com>
The patch is created off 2.6.19.
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Index: linux/arch/ia64/sn/kernel/setup.c
===================================================================
--- linux.orig/arch/ia64/sn/kernel/setup.c 2006-11-29 13:57:37.000000000 -0800
+++ linux/arch/ia64/sn/kernel/setup.c 2006-12-11 15:31:16.700848251 -0800
@@ -562,7 +562,7 @@ void __cpuinit sn_cpu_init(void)
int slice;
int cnode;
int i;
- static int wars_have_been_checked;
+ static int wars_have_been_checked, set_cpu0_number;
cpuid = smp_processor_id();
if (cpuid == 0 && IS_MEDUSA()) {
@@ -587,8 +587,16 @@ void __cpuinit sn_cpu_init(void)
/*
* Don't check status. The SAL call is not supported on all PROMs
* but a failure is harmless.
+ * Architechtuallly, cpu_init is always called twice on cpu 0. We
+ * should set cpu_number on cpu 0 once.
*/
- (void) ia64_sn_set_cpu_number(cpuid);
+ if (cpuid == 0) {
+ if (!set_cpu0_number) {
+ (void) ia64_sn_set_cpu_number(cpuid);
+ set_cpu0_number = 1;
+ }
+ } else
+ (void) ia64_sn_set_cpu_number(cpuid);
/*
* The boot cpu makes this call again after platform initialization is
reply other threads:[~2006-12-11 23:39 UTC|newest]
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