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* [PATCH] x86,perf: Unmask LVTPC only if we have APIC supported
@ 2010-03-13  8:11 Cyrill Gorcunov
  2010-03-13 12:24 ` Ingo Molnar
  2010-03-13 16:21 ` [tip:perf/core] x86, perf: " tip-bot for Cyrill Gorcunov
  0 siblings, 2 replies; 10+ messages in thread
From: Cyrill Gorcunov @ 2010-03-13  8:11 UTC (permalink / raw)
  To: Ingo Molnar; +Cc: Lin Ming, Peter Zijlstra, LKML

Ingo reported
|
| There's a build failure on -tip with the P4 driver, on UP 32-bit, if
| PERF_EVENTS is enabled but UP_APIC is disabled:
|
| arch/x86/built-in.o: In function `p4_pmu_handle_irq':
| perf_event.c:(.text+0xa756): undefined reference to `apic'
| perf_event.c:(.text+0xa76e): undefined reference to `apic'
|

So we have to unmask LVTPC only if we're configured to have one.

Reported-by: Ingo Molnar <mingo@elte.hu>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
---
 arch/x86/kernel/cpu/perf_event_p4.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
=====================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_p4.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
@@ -365,8 +365,10 @@ static int p4_pmu_handle_irq(struct pt_r
 	}
 
 	if (handled) {
+#ifdef CONFIG_X86_LOCAL_APIC
 		/* p4 quirk: unmask it again */
 		apic_write(APIC_LVTPC, apic_read(APIC_LVTPC) & ~APIC_LVT_MASKED);
+#endif
 		inc_irq_stat(apic_perf_irqs);
 	}
 

^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2010-03-13 16:22 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-03-13  8:11 [PATCH] x86,perf: Unmask LVTPC only if we have APIC supported Cyrill Gorcunov
2010-03-13 12:24 ` Ingo Molnar
2010-03-13 12:32   ` Cyrill Gorcunov
2010-03-13 12:40     ` Ingo Molnar
2010-03-13 12:42       ` Ingo Molnar
2010-03-13 13:42       ` Cyrill Gorcunov
2010-03-13 13:50         ` Ingo Molnar
2010-03-13 14:08           ` Cyrill Gorcunov
2010-03-13 15:03           ` Cyrill Gorcunov
2010-03-13 16:21 ` [tip:perf/core] x86, perf: " tip-bot for Cyrill Gorcunov

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