Messages in this thread | | | From | Namhyung Kim <> | Date | Thu, 22 Oct 2015 16:16:23 +0900 | Subject | Re: [PATCH 26/31] perf tools: Support perf event alias name |
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Hi,
On Wed, Oct 21, 2015 at 10:00 PM, Wangnan (F) <wangnan0@huawei.com> wrote: > > > On 2015/10/21 16:53, Namhyung Kim wrote: >> >> Hi, >> >> On Wed, Oct 14, 2015 at 12:41:37PM +0000, Wang Nan wrote: >>> >>> From: He Kuang <hekuang@huawei.com> >>> >>> This patch adds new bison rules for specifying an alias name to a perf >>> event, which allows cmdline refer to previous defined perf event through >>> its name. With this patch user can give alias name to a perf event using >>> following cmdline: >>> >>> # perf record -e mypmu=cycles ... >>> >>> To allow parser refer to existing event selecter, pass event list to >>> 'struct parse_events_evlist'. perf_evlist__find_evsel_by_alias() is >>> introduced to get evsel through its alias. >> >> What about using event name directly? I guess the alias name is used >> only to refer an event so it'd be better to use the event name. >> Anyway we need alias as well when event has no name or name is complex. > > > It is possible to trigger two perf events with same PMU but > different config options: > > # perf record -e cycles/period=9999/ -e cycles/period=99999/ -a sleep 1 > > In this case the name of events are: > > cycles/period=9999/ ` > cycles/period=99999/ > > Using it in perf cmdline is painful: > > # perf record -e cycles/period=9999/ -e cycles/period=99999/ -e > bpf_program.c/myevent=cycles/period=9999//...
I understand the need of using aliases but I think it's more natural to use event name for simple cases..
Thanks, Namhyung
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