Messages in this thread | | | Date | Fri, 24 Mar 2023 12:30:31 +0000 | From | Jonathan Cameron <> | Subject | Re: [PATCH] perf stat: Support per-cluster aggregation |
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On Fri, 24 Mar 2023 12:24:22 +0000 Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote:
> On Fri, 24 Mar 2023 10:34:33 +0800 > Jie Zhan <zhanjie9@hisilicon.com> wrote: > > > On 13/03/2023 16:59, Yicong Yang wrote: > > > From: Yicong Yang <yangyicong@hisilicon.com> > > > > > > Some platforms have 'cluster' topology and CPUs in the cluster will > > > share resources like L3 Cache Tag (for HiSilicon Kunpeng SoC) or L2 > > > cache (for Intel Jacobsville). Currently parsing and building cluster > > > topology have been supported since [1]. > > > > > > perf stat has already supported aggregation for other topologies like > > > die or socket, etc. It'll be useful to aggregate per-cluster to find > > > problems like L3T bandwidth contention or imbalance. > > > > > > This patch adds support for "--per-cluster" option for per-cluster > > > aggregation. Also update the docs and related test. The output will > > > be like: > > > > > > [root@localhost tmp]# perf stat -a -e LLC-load --per-cluster -- sleep 5 > > > > > > Performance counter stats for 'system wide': > > > > > > S56-D0-CLS158 4 1,321,521,570 LLC-load > > > S56-D0-CLS594 4 794,211,453 LLC-load > > > S56-D0-CLS1030 4 41,623 LLC-load > > > S56-D0-CLS1466 4 41,646 LLC-load > > > S56-D0-CLS1902 4 16,863 LLC-load > > > S56-D0-CLS2338 4 15,721 LLC-load > > > S56-D0-CLS2774 4 22,671 LLC-load > > > [...] > > > > > > [1] commit c5e22feffdd7 ("topology: Represent clusters of CPUs within a die") > > > > > > Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> > > > > An end user may have to check sysfs to figure out what CPUs those > > cluster IDs account for. > > > > Any better method to show the mapping between CPUs and cluster IDs? > > The cluster code is capable of using the ACPI_PPTT_ACPI_PROCESSOR_ID field > if valid for the cluster level of PPTT. > > The numbers in the example above look like offsets into the PPTT table > so I think the PPTT table is missing that information. > > Whilst not a great description anyway (it's just an index), the UUID > that would be in there can convey more info on which cluster this is. > > > > > > Perhaps adding a conditional cluster id (when there are clusters) in the > > "--per-core" output may help. > > That's an interesting idea. You'd want to include the other levels > if doing that. So whenever you do a --per-xxx it also provides the > cluster / die / node / socket etc as relevant 'above' the level of xxx > Fun is that node and die can flip which would make this tricky to do.
Ignore me on this. I'd not looked at the patch closely when I wrote this. Clearly a lot of this information is already provided - the suggestion was to consider adding cluster to that mix which makes sense to me.
Jonathan
> > Jonathan > > > > > Apart form that, this works well on my aarch64. > > > > Tested-by: Jie Zhan <zhanjie9@hisilicon.com> > > > > > >
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