Messages in this thread | | | From | Ian Rogers <> | Date | Wed, 19 Jul 2023 09:55:39 -0700 | Subject | Re: [PATCH] perf: add new option '--workload-attr' to set workload sched_policy/priority/mask |
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On Fri, Jul 14, 2023 at 12:19 AM Changbin Du <changbin.du@huawei.com> wrote: > > On Fri, Jul 14, 2023 at 10:06:31AM +0300, Adrian Hunter wrote: > > On 13/07/23 11:58, Changbin Du wrote: > > > To get consistent benchmarking results, sometimes we need to set the > > > sched_policy/priority/mask of the workload to reduce system noise. > > > > > > For example, CPU binding is required on big.little system. > > > > > > $ perf stat -r 10 -- taskset -c 0 ls > > > > > > Nevertheless, the 'taskset' is also counted here. > > > > > > To get away of the middleman, this adds a new option '--workload-attr' to > > > do the same jobs for stat and record commands. > > > > > > $ sudo perf stat --workload-attr fifo,40,0x1 -- ls > > > > > > Above will make 'ls' run on CPU #0 with fifo scheduler and realtime > > > priority is 40. > > > > Aren't there ways to set up a process then start perf using -p <pid> > > then let the process continue. > > > By that you need a mechanism to pause the new spawnned process and wait perf to > attach. Or setup the sched properties by the app itself. But sometimes we just > simply want to run the app through and measure some events. With > --workload-attr, we do not need extra setup works.
To my naive eyes this looks to be a broadly useful addition. Some thoughts: - "cpu-mask" as the command line argument name, this is "-C" and "--cpu" elsewhere, so perhaps just "cpu" as the mask is perhaps confusing. - could we get a test? Perhaps add a case to tools/perf/tests/shell/stat.sh: https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/tests/shell/stat.sh?h=perf-tools-next
Thanks, Ian
> -- > Cheers, > Changbin Du
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