[PATCH] x86,perf: Unmask LVTPC only if we have APIC supported
- Date: Sat, 13 Mar 2010 11:11:16 +0300
- From: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
- Subject: [PATCH] x86,perf: Unmask LVTPC only if we have APIC supported
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@xxxxxxx>
CC: Lin Ming <ming.m.lin@xxxxxxxxx>
CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
---
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);
}
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