Messages in this thread | | | Subject | Re: [PATCH 2/3] perf tools: Allow to enable/disable events via control file | From | Alexei Budankov <> | Date | Thu, 10 Dec 2020 21:32:48 +0300 |
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On 10.12.2020 21:20, Alexei Budankov wrote: > > On 10.12.2020 21:06, Jiri Olsa wrote: >> On Thu, Dec 10, 2020 at 05:24:30PM +0100, Jiri Olsa wrote: >>> On Mon, Dec 07, 2020 at 08:02:20PM +0300, Alexei Budankov wrote: >>>> Hi, >>>> >>>> On 06.12.2020 20:05, Jiri Olsa wrote: >>>>> Adding new control events to enable/disable specific event. >>>>> The interface string for control file are: >>>>> >>>>> 'enable-<EVENT NAME>' >>>>> 'disable-<EVENT NAME>' >>>> >>>> <SNIP> >>>> >>>>> >>>>> when received the command, perf will scan the current evlist >>>>> for <EVENT NAME> and if found it's enabled/disabled. >>>> >>>> <SNIP> >>>> >>>>> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c >>>>> index 70aff26612a9..05723227bebf 100644 >>>>> --- a/tools/perf/util/evlist.c >>>>> +++ b/tools/perf/util/evlist.c >>>>> @@ -1915,7 +1915,13 @@ static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd, >>>>> bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0"); >>>>> >>>>> if (bytes_read > 0) { >>>>> - if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG, >>>>> + if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_EVSEL_TAG, >>>>> + (sizeof(EVLIST_CTL_CMD_ENABLE_EVSEL_TAG)-1))) { >>>>> + *cmd = EVLIST_CTL_CMD_ENABLE_EVSEL; >>>>> + } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_EVSEL_TAG, >>>>> + (sizeof(EVLIST_CTL_CMD_DISABLE_EVSEL_TAG)-1))) { >>>>> + *cmd = EVLIST_CTL_CMD_DISABLE_EVSEL; >>>>> + } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG, >>>>> (sizeof(EVLIST_CTL_CMD_ENABLE_TAG)-1))) { >>>>> *cmd = EVLIST_CTL_CMD_ENABLE; >>>>> } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG, >>>>> @@ -1952,6 +1958,8 @@ int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd) >>>>> char cmd_data[EVLIST_CTL_CMD_MAX_LEN]; >>>>> int ctlfd_pos = evlist->ctl_fd.pos; >>>>> struct pollfd *entries = evlist->core.pollfd.entries; >>>>> + struct evsel *evsel; >>>>> + char *evsel_name; >>>>> >>>>> if (!evlist__ctlfd_initialized(evlist) || !entries[ctlfd_pos].revents) >>>>> return 0; >>>>> @@ -1967,6 +1975,26 @@ int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd) >>>>> case EVLIST_CTL_CMD_DISABLE: >>>>> evlist__disable(evlist); >>>>> break; >>>>> + case EVLIST_CTL_CMD_ENABLE_EVSEL: >>>>> + evsel_name = cmd_data + sizeof(EVLIST_CTL_CMD_ENABLE_EVSEL_TAG) - 1; >>>> >>>> It makes sense to check that evsel_name still points >>>> into cmd_data buffer after assigning to event name. >>> >>> right, will add that >> >> actualy it's already checked in evlist__ctlfd_recv, evsel_name at >> worst will be empty string so evlist__find_evsel_by_str will fail >> >> I'll add '' around %s in the error output string: >> >> failed: can't find '%s' event >> >> so it's obvious when it's empty
Acked-by: Alexei Budankov <abudankov@huawei.com>
Thanks, Alexei
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