From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 25 May 2009 19:41:28 +0000 (+0200)
Subject: Revert "perf_counter, x86: speed up the scheduling fast-path"
X-Git-Tag: v2.6.31-rc1~383^2~223
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=53b441a565bf4036ab49c8ea04c5ad06ace7dd6b;p=karo-tx-linux.git

Revert "perf_counter, x86: speed up the scheduling fast-path"

This reverts commit b68f1d2e7aa21029d73c7d453a8046e95d351740.

It is causing problems (stuck/stuttering profiling) - when mixed
NMI and non-NMI counters are used.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525153931.703093461@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index c4b543d1a86f..189bf9d7cdab 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -293,7 +293,6 @@ static int __hw_perf_counter_init(struct perf_counter *counter)
 			return -EACCES;
 		hwc->nmi = 1;
 	}
-	perf_counters_lapic_init(hwc->nmi);
 
 	if (!hwc->irq_period)
 		hwc->irq_period = x86_pmu.max_period;
@@ -612,6 +611,8 @@ try_generic:
 		hwc->counter_base = x86_pmu.perfctr;
 	}
 
+	perf_counters_lapic_init(hwc->nmi);
+
 	x86_pmu.disable(hwc, idx);
 
 	cpuc->counters[idx] = counter;
@@ -1037,7 +1038,7 @@ void __init init_hw_perf_counters(void)
 
 	pr_info("... counter mask:    %016Lx\n", perf_counter_mask);
 
-	perf_counters_lapic_init(1);
+	perf_counters_lapic_init(0);
 	register_die_notifier(&perf_counter_nmi_notifier);
 }