* [PATCH] perf vendor events: Fix DRAM_BW_Use 0 issue for CLX/SKX
@ 2020-10-23 0:53 Jin Yao
2020-10-23 1:02 ` Ian Rogers
0 siblings, 1 reply; 3+ messages in thread
From: Jin Yao @ 2020-10-23 0:53 UTC (permalink / raw)
To: acme, jolsa, peterz, mingo, alexander.shishkin
Cc: Linux-kernel, ak, kan.liang, yao.jin, irogers, Jin Yao
Ian reports an issue that the metric DRAM_BW_Use often remains 0.
The metric expression for DRAM_BW_Use on CLX/SKX:
"( 64 * ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) / 1000000000 ) / duration_time"
The counts of uncore_imc/cas_count_read/ and uncore_imc/cas_count_write/
are scaled up by 64, that is to turn a count of cache lines into bytes,
the count is then divided by 1000000000 to give GB.
However, the counts of uncore_imc/cas_count_read/ and
uncore_imc/cas_count_write/ have been scaled yet.
The scale values are from sysfs, such as
/sys/devices/uncore_imc_0/events/cas_count_read.scale.
It's 6.103515625e-5 (64 / 1024.0 / 1024.0).
So if we use original metric expression, the result is not correct.
But the difficulty is, for SKL client, the counts are not scaled.
The metric expression for DRAM_BW_Use on SKL:
"64 * ( arb@event\\=0x81\\,umask\\=0x1@ + arb@event\\=0x84\\,umask\\=0x1@ ) / 1000000 / duration_time / 1000"
root@kbl-ppc:~# perf stat -M DRAM_BW_Use -a -- sleep 1
Performance counter stats for 'system wide':
190 arb/event=0x84,umask=0x1/ # 1.86 DRAM_BW_Use
29,093,178 arb/event=0x81,umask=0x1/
1,000,703,287 ns duration_time
1.000703287 seconds time elapsed
The result is expected.
So the easy way is just change the metric expression for CLX/SKX.
This patch changes the metric expression to:
"( ( ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) * 1048576 ) / 1000000000 ) / duration_time"
1048576 = 1024 * 1024.
Before (tested on CLX):
root@lkp-csl-2sp5 ~# perf stat -M DRAM_BW_Use -a -- sleep 1
Performance counter stats for 'system wide':
765.35 MiB uncore_imc/cas_count_read/ # 0.00 DRAM_BW_Use
5.42 MiB uncore_imc/cas_count_write/
1001515088 ns duration_time
1.001515088 seconds time elapsed
After:
root@lkp-csl-2sp5 ~# perf stat -M DRAM_BW_Use -a -- sleep 1
Performance counter stats for 'system wide':
767.95 MiB uncore_imc/cas_count_read/ # 0.80 DRAM_BW_Use
5.02 MiB uncore_imc/cas_count_write/
1001900010 ns duration_time
1.001900010 seconds time elapsed
Fixes: 038d3b53c284 ("perf vendor events intel: Update CascadelakeX events to v1.08")
Fixes: b5ff7f2799a4 ("perf vendor events: Update SkylakeX events to v1.21")
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json | 2 +-
tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json b/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json
index de3193552277..00f4fcffa815 100644
--- a/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json
+++ b/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json
@@ -329,7 +329,7 @@
},
{
"BriefDescription": "Average external Memory Bandwidth Use for reads and writes [GB / sec]",
- "MetricExpr": "( 64 * ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) / 1000000000 ) / duration_time",
+ "MetricExpr": "( ( ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) * 1048576 ) / 1000000000 ) / duration_time",
"MetricGroup": "Memory_BW;SoC",
"MetricName": "DRAM_BW_Use"
},
diff --git a/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json b/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json
index f31794d3b926..0dd8b13b5cfb 100644
--- a/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json
+++ b/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json
@@ -323,7 +323,7 @@
},
{
"BriefDescription": "Average external Memory Bandwidth Use for reads and writes [GB / sec]",
- "MetricExpr": "( 64 * ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) / 1000000000 ) / duration_time",
+ "MetricExpr": "( ( ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) * 1048576 ) / 1000000000 ) / duration_time",
"MetricGroup": "Memory_BW;SoC",
"MetricName": "DRAM_BW_Use"
},
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] perf vendor events: Fix DRAM_BW_Use 0 issue for CLX/SKX
2020-10-23 0:53 [PATCH] perf vendor events: Fix DRAM_BW_Use 0 issue for CLX/SKX Jin Yao
@ 2020-10-23 1:02 ` Ian Rogers
2020-10-27 16:20 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 3+ messages in thread
From: Ian Rogers @ 2020-10-23 1:02 UTC (permalink / raw)
To: Jin Yao
Cc: Arnaldo Carvalho de Melo, Jiri Olsa, Peter Zijlstra, Ingo Molnar,
Alexander Shishkin, LKML, Andi Kleen, Kan Liang, Jin, Yao
On Thu, Oct 22, 2020 at 5:54 PM Jin Yao <yao.jin@linux.intel.com> wrote:
>
> Ian reports an issue that the metric DRAM_BW_Use often remains 0.
>
> The metric expression for DRAM_BW_Use on CLX/SKX:
>
> "( 64 * ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) / 1000000000 ) / duration_time"
>
> The counts of uncore_imc/cas_count_read/ and uncore_imc/cas_count_write/
> are scaled up by 64, that is to turn a count of cache lines into bytes,
> the count is then divided by 1000000000 to give GB.
>
> However, the counts of uncore_imc/cas_count_read/ and
> uncore_imc/cas_count_write/ have been scaled yet.
>
> The scale values are from sysfs, such as
> /sys/devices/uncore_imc_0/events/cas_count_read.scale.
> It's 6.103515625e-5 (64 / 1024.0 / 1024.0).
>
> So if we use original metric expression, the result is not correct.
>
> But the difficulty is, for SKL client, the counts are not scaled.
>
> The metric expression for DRAM_BW_Use on SKL:
>
> "64 * ( arb@event\\=0x81\\,umask\\=0x1@ + arb@event\\=0x84\\,umask\\=0x1@ ) / 1000000 / duration_time / 1000"
>
> root@kbl-ppc:~# perf stat -M DRAM_BW_Use -a -- sleep 1
>
> Performance counter stats for 'system wide':
>
> 190 arb/event=0x84,umask=0x1/ # 1.86 DRAM_BW_Use
> 29,093,178 arb/event=0x81,umask=0x1/
> 1,000,703,287 ns duration_time
>
> 1.000703287 seconds time elapsed
>
> The result is expected.
>
> So the easy way is just change the metric expression for CLX/SKX.
> This patch changes the metric expression to:
>
> "( ( ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) * 1048576 ) / 1000000000 ) / duration_time"
>
> 1048576 = 1024 * 1024.
>
> Before (tested on CLX):
>
> root@lkp-csl-2sp5 ~# perf stat -M DRAM_BW_Use -a -- sleep 1
>
> Performance counter stats for 'system wide':
>
> 765.35 MiB uncore_imc/cas_count_read/ # 0.00 DRAM_BW_Use
> 5.42 MiB uncore_imc/cas_count_write/
> 1001515088 ns duration_time
>
> 1.001515088 seconds time elapsed
>
> After:
>
> root@lkp-csl-2sp5 ~# perf stat -M DRAM_BW_Use -a -- sleep 1
>
> Performance counter stats for 'system wide':
>
> 767.95 MiB uncore_imc/cas_count_read/ # 0.80 DRAM_BW_Use
Nit, using ScaleUnit would allow this to be 0.80GB/s.
> 5.02 MiB uncore_imc/cas_count_write/
> 1001900010 ns duration_time
>
> 1.001900010 seconds time elapsed
>
> Fixes: 038d3b53c284 ("perf vendor events intel: Update CascadelakeX events to v1.08")
> Fixes: b5ff7f2799a4 ("perf vendor events: Update SkylakeX events to v1.21")
> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Thanks,
Ian
> ---
> tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json | 2 +-
> tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json b/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json
> index de3193552277..00f4fcffa815 100644
> --- a/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json
> +++ b/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json
> @@ -329,7 +329,7 @@
> },
> {
> "BriefDescription": "Average external Memory Bandwidth Use for reads and writes [GB / sec]",
> - "MetricExpr": "( 64 * ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) / 1000000000 ) / duration_time",
> + "MetricExpr": "( ( ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) * 1048576 ) / 1000000000 ) / duration_time",
> "MetricGroup": "Memory_BW;SoC",
> "MetricName": "DRAM_BW_Use"
> },
> diff --git a/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json b/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json
> index f31794d3b926..0dd8b13b5cfb 100644
> --- a/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json
> +++ b/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json
> @@ -323,7 +323,7 @@
> },
> {
> "BriefDescription": "Average external Memory Bandwidth Use for reads and writes [GB / sec]",
> - "MetricExpr": "( 64 * ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) / 1000000000 ) / duration_time",
> + "MetricExpr": "( ( ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) * 1048576 ) / 1000000000 ) / duration_time",
> "MetricGroup": "Memory_BW;SoC",
> "MetricName": "DRAM_BW_Use"
> },
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] perf vendor events: Fix DRAM_BW_Use 0 issue for CLX/SKX
2020-10-23 1:02 ` Ian Rogers
@ 2020-10-27 16:20 ` Arnaldo Carvalho de Melo
0 siblings, 0 replies; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2020-10-27 16:20 UTC (permalink / raw)
To: Ian Rogers
Cc: Jin Yao, Jiri Olsa, Peter Zijlstra, Ingo Molnar,
Alexander Shishkin, LKML, Andi Kleen, Kan Liang, Jin, Yao
Em Thu, Oct 22, 2020 at 06:02:31PM -0700, Ian Rogers escreveu:
> On Thu, Oct 22, 2020 at 5:54 PM Jin Yao <yao.jin@linux.intel.com> wrote:
> >
> > Ian reports an issue that the metric DRAM_BW_Use often remains 0.
> >
> > The metric expression for DRAM_BW_Use on CLX/SKX:
> >
> > "( 64 * ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) / 1000000000 ) / duration_time"
> >
> > The counts of uncore_imc/cas_count_read/ and uncore_imc/cas_count_write/
> > are scaled up by 64, that is to turn a count of cache lines into bytes,
> > the count is then divided by 1000000000 to give GB.
> >
> > However, the counts of uncore_imc/cas_count_read/ and
> > uncore_imc/cas_count_write/ have been scaled yet.
> >
> > The scale values are from sysfs, such as
> > /sys/devices/uncore_imc_0/events/cas_count_read.scale.
> > It's 6.103515625e-5 (64 / 1024.0 / 1024.0).
> >
> > So if we use original metric expression, the result is not correct.
> >
> > But the difficulty is, for SKL client, the counts are not scaled.
> >
> > The metric expression for DRAM_BW_Use on SKL:
> >
> > "64 * ( arb@event\\=0x81\\,umask\\=0x1@ + arb@event\\=0x84\\,umask\\=0x1@ ) / 1000000 / duration_time / 1000"
> >
> > root@kbl-ppc:~# perf stat -M DRAM_BW_Use -a -- sleep 1
> >
> > Performance counter stats for 'system wide':
> >
> > 190 arb/event=0x84,umask=0x1/ # 1.86 DRAM_BW_Use
> > 29,093,178 arb/event=0x81,umask=0x1/
> > 1,000,703,287 ns duration_time
> >
> > 1.000703287 seconds time elapsed
> >
> > The result is expected.
> >
> > So the easy way is just change the metric expression for CLX/SKX.
> > This patch changes the metric expression to:
> >
> > "( ( ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) * 1048576 ) / 1000000000 ) / duration_time"
> >
> > 1048576 = 1024 * 1024.
> >
> > Before (tested on CLX):
> >
> > root@lkp-csl-2sp5 ~# perf stat -M DRAM_BW_Use -a -- sleep 1
> >
> > Performance counter stats for 'system wide':
> >
> > 765.35 MiB uncore_imc/cas_count_read/ # 0.00 DRAM_BW_Use
> > 5.42 MiB uncore_imc/cas_count_write/
> > 1001515088 ns duration_time
> >
> > 1.001515088 seconds time elapsed
> >
> > After:
> >
> > root@lkp-csl-2sp5 ~# perf stat -M DRAM_BW_Use -a -- sleep 1
> >
> > Performance counter stats for 'system wide':
> >
> > 767.95 MiB uncore_imc/cas_count_read/ # 0.80 DRAM_BW_Use
>
> Nit, using ScaleUnit would allow this to be 0.80GB/s.
>
> > 5.02 MiB uncore_imc/cas_count_write/
> > 1001900010 ns duration_time
> >
> > 1.001900010 seconds time elapsed
> >
> > Fixes: 038d3b53c284 ("perf vendor events intel: Update CascadelakeX events to v1.08")
> > Fixes: b5ff7f2799a4 ("perf vendor events: Update SkylakeX events to v1.21")
> > Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
>
> Acked-by: Ian Rogers <irogers@google.com>
Thanks, applied.
- Arnaldo
> Thanks,
> Ian
>
> > ---
> > tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json | 2 +-
> > tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json | 2 +-
> > 2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json b/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json
> > index de3193552277..00f4fcffa815 100644
> > --- a/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json
> > +++ b/tools/perf/pmu-events/arch/x86/cascadelakex/clx-metrics.json
> > @@ -329,7 +329,7 @@
> > },
> > {
> > "BriefDescription": "Average external Memory Bandwidth Use for reads and writes [GB / sec]",
> > - "MetricExpr": "( 64 * ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) / 1000000000 ) / duration_time",
> > + "MetricExpr": "( ( ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) * 1048576 ) / 1000000000 ) / duration_time",
> > "MetricGroup": "Memory_BW;SoC",
> > "MetricName": "DRAM_BW_Use"
> > },
> > diff --git a/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json b/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json
> > index f31794d3b926..0dd8b13b5cfb 100644
> > --- a/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json
> > +++ b/tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json
> > @@ -323,7 +323,7 @@
> > },
> > {
> > "BriefDescription": "Average external Memory Bandwidth Use for reads and writes [GB / sec]",
> > - "MetricExpr": "( 64 * ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) / 1000000000 ) / duration_time",
> > + "MetricExpr": "( ( ( uncore_imc@cas_count_read@ + uncore_imc@cas_count_write@ ) * 1048576 ) / 1000000000 ) / duration_time",
> > "MetricGroup": "Memory_BW;SoC",
> > "MetricName": "DRAM_BW_Use"
> > },
> > --
> > 2.17.1
> >
--
- Arnaldo
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-10-23 0:53 [PATCH] perf vendor events: Fix DRAM_BW_Use 0 issue for CLX/SKX Jin Yao
2020-10-23 1:02 ` Ian Rogers
2020-10-27 16:20 ` Arnaldo Carvalho de Melo
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