The patch titled
x86: reserve the right performance counter for the Intel PerfMon NMI watchdog
has been added to the -mm tree. Its filename is
reserve-the-right-performance-counter-for-the-intel-perfmon-nmi-watchdog.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: x86: reserve the right performance counter for the Intel PerfMon NMI watchdog
From: Björn Steinbrink <B.Steinbrink@xxxxxx>
The Intel PerfMon NMI watchdog was using the generic reservation function
which always reserves the first performance counter. But the watchdog
actually uses the second performance counter, thus we need a specialised
function.
Signed-off-by: Björn Steinbrink <B.Steinbrink@xxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: John Levon <levon@xxxxxxxxxxxxxxxxx>
Cc: Philippe Elie <phil.el@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/i386/kernel/cpu/perfctr-watchdog.c | 22 ++++++++++++++++++++--
1 files changed, 20 insertions(+), 2 deletions(-)
diff -puN arch/i386/kernel/cpu/perfctr-watchdog.c~reserve-the-right-performance-counter-for-the-intel-perfmon-nmi-watchdog arch/i386/kernel/cpu/perfctr-watchdog.c
--- a/arch/i386/kernel/cpu/perfctr-watchdog.c~reserve-the-right-performance-counter-for-the-intel-perfmon-nmi-watchdog
+++ a/arch/i386/kernel/cpu/perfctr-watchdog.c
@@ -562,9 +562,27 @@ static int setup_intel_arch_watchdog(uns
return 1;
}
+static int intel_arch_reserve(void)
+{
+ if (!reserve_perfctr_nmi(MSR_ARCH_PERFMON_PERFCTR1))
+ return 0;
+
+ if (!reserve_evntsel_nmi(MSR_ARCH_PERFMON_EVENTSEL1)) {
+ release_perfctr_nmi(MSR_ARCH_PERFMON_PERFCTR1);
+ return 0;
+ }
+ return 1;
+}
+
+static void intel_arch_unreserve(void)
+{
+ release_evntsel_nmi(MSR_ARCH_PERFMON_EVENTSEL1);
+ release_perfctr_nmi(MSR_ARCH_PERFMON_PERFCTR1);
+}
+
static struct wd_ops intel_arch_wd_ops = {
- .reserve = single_msr_reserve,
- .unreserve = single_msr_unreserve,
+ .reserve = intel_arch_reserve,
+ .unreserve = intel_arch_unreserve,
.setup = setup_intel_arch_watchdog,
.rearm = p6_rearm,
.stop = single_msr_stop_watchdog,
_
Patches currently in -mm which might be from B.Steinbrink@xxxxxx are
always-probe-the-nmi-watchdog.patch
reserve-the-right-performance-counter-for-the-intel-perfmon-nmi-watchdog.patch
-
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