Messages in this thread | | | Date | Fri, 24 Mar 2023 12:24:22 +0000 | From | Jonathan Cameron <> | Subject | Re: [PATCH] perf stat: Support per-cluster aggregation |
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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.
Jonathan
> > Apart form that, this works well on my aarch64. > > Tested-by: Jie Zhan <zhanjie9@hisilicon.com>
> >
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