This is a note to let you know that I've just added the patch titled
sparc: perf: Make counting mode actually work
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sparc-perf-make-counting-mode-actually-work.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Mar 24 10:57:46 CET 2015
From: David Ahern <david.ahern@xxxxxxxxxx>
Date: Thu, 19 Mar 2015 16:06:17 -0400
Subject: sparc: perf: Make counting mode actually work
From: David Ahern <david.ahern@xxxxxxxxxx>
[ Upstream commit d51291cb8f32bfae6b331e1838651f3ddefa73a5 ]
Currently perf-stat (aka, counting mode) does not work:
$ perf stat ls
...
Performance counter stats for 'ls':
1.585665 task-clock (msec) # 0.580 CPUs utilized
24 context-switches # 0.015 M/sec
0 cpu-migrations # 0.000 K/sec
86 page-faults # 0.054 M/sec
<not supported> cycles
<not supported> stalled-cycles-frontend
<not supported> stalled-cycles-backend
<not supported> instructions
<not supported> branches
<not supported> branch-misses
0.002735100 seconds time elapsed
The reason is that state is never reset (stays with PERF_HES_UPTODATE set).
Add a call to sparc_pmu_enable_event during the added_event handling.
Clean up the encoding since pmu_start calls sparc_pmu_enable_event which
does the same. Passing PERF_EF_RELOAD to sparc_pmu_start means the call
to sparc_perf_event_set_period can be removed as well.
With this patch:
$ perf stat ls
...
Performance counter stats for 'ls':
1.552890 task-clock (msec) # 0.552 CPUs utilized
24 context-switches # 0.015 M/sec
0 cpu-migrations # 0.000 K/sec
86 page-faults # 0.055 M/sec
5,748,997 cycles # 3.702 GHz
<not supported> stalled-cycles-frontend:HG
<not supported> stalled-cycles-backend:HG
1,684,362 instructions:HG # 0.29 insns per cycle
295,133 branches:HG # 190.054 M/sec
28,007 branch-misses:HG # 9.49% of all branches
0.002815665 seconds time elapsed
Signed-off-by: David Ahern <david.ahern@xxxxxxxxxx>
Acked-by: Bob Picco <bob.picco@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/sparc/kernel/perf_event.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -960,6 +960,8 @@ out:
cpuc->pcr[0] |= cpuc->event[0]->hw.config_base;
}
+static void sparc_pmu_start(struct perf_event *event, int flags);
+
/* On this PMU each PIC has it's own PCR control register. */
static void calculate_multiple_pcrs(struct cpu_hw_events *cpuc)
{
@@ -972,20 +974,13 @@ static void calculate_multiple_pcrs(stru
struct perf_event *cp = cpuc->event[i];
struct hw_perf_event *hwc = &cp->hw;
int idx = hwc->idx;
- u64 enc;
if (cpuc->current_idx[i] != PIC_NO_INDEX)
continue;
- sparc_perf_event_set_period(cp, hwc, idx);
cpuc->current_idx[i] = idx;
- enc = perf_event_get_enc(cpuc->events[i]);
- cpuc->pcr[idx] &= ~mask_for_index(idx);
- if (hwc->state & PERF_HES_STOPPED)
- cpuc->pcr[idx] |= nop_for_index(idx);
- else
- cpuc->pcr[idx] |= event_encoding(enc, idx);
+ sparc_pmu_start(cp, PERF_EF_RELOAD);
}
out:
for (i = 0; i < cpuc->n_events; i++) {
Patches currently in stable-queue which might be from david.ahern@xxxxxxxxxx are
queue-3.10/sparc64-fix-several-bugs-in-memmove.patch
queue-3.10/sparc-perf-make-counting-mode-actually-work.patch
queue-3.10/sparc-touch-nmi-watchdog-when-walking-cpus-and-calling-printk.patch
queue-3.10/sparc-perf-remove-redundant-perf_pmu_-en-dis-able-calls.patch
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