From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1D75CE7A8B for ; Mon, 25 Sep 2023 02:20:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231613AbjIYCUL (ORCPT ); Sun, 24 Sep 2023 22:20:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59216 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229561AbjIYCUK (ORCPT ); Sun, 24 Sep 2023 22:20:10 -0400 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03E6FCF; Sun, 24 Sep 2023 19:20:01 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=renyu.zj@linux.alibaba.com;NM=1;PH=DS;RN=20;SR=0;TI=SMTPD_---0VsjlH5P_1695608397; Received: from 30.221.145.8(mailfrom:renyu.zj@linux.alibaba.com fp:SMTPD_---0VsjlH5P_1695608397) by smtp.aliyun-inc.com; Mon, 25 Sep 2023 10:19:59 +0800 Message-ID: Date: Mon, 25 Sep 2023 10:19:55 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.15.0 Subject: Re: [PATCH v9 1/7] perf pmu: "Compat" supports regular expression matching identifiers To: Ian Rogers Cc: John Garry , Will Deacon , James Clark , Arnaldo Carvalho de Melo , Mark Rutland , Mike Leach , Leo Yan , Namhyung Kim , Peter Zijlstra , Ingo Molnar , Alexander Shishkin , Jiri Olsa , Adrian Hunter , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-doc@vger.kernel.org, Zhuo Song , Shuai Xue References: <1695037955-107983-1-git-send-email-renyu.zj@linux.alibaba.com> <1695037955-107983-2-git-send-email-renyu.zj@linux.alibaba.com> <0f5bbe93-1875-ff9b-a1d8-8518a8cf3e84@linux.alibaba.com> From: Jing Zhang In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2023/9/22 下午10:58, Ian Rogers 写道: > On Fri, Sep 22, 2023 at 1:19 AM Jing Zhang wrote: >> >> >> >> 在 2023/9/21 上午2:36, Ian Rogers 写道: >>> On Mon, Sep 18, 2023 at 4:52 AM Jing Zhang wrote: >>>> >>>> The jevent "Compat" is used for uncore PMU alias or metric definitions. >>>> >>>> The same PMU driver has different PMU identifiers due to different >>>> hardware versions and types, but they may have some common PMU event. >>>> Since a Compat value can only match one identifier, when adding the >>>> same event alias to PMUs with different identifiers, each identifier >>>> needs to be defined once, which is not streamlined enough. >>>> >>>> So let "Compat" support using regular expression to match identifiers >>>> for uncore PMU alias. For example, if the "Compat" value is set to >>>> "43401|43c01", it would be able to match PMU identifiers such as "43401" >>>> or "43c01", which correspond to CMN600_r0p0 or CMN700_r0p0. >>>> >>>> Signed-off-by: Jing Zhang >>>> --- >>>> tools/perf/util/pmu.c | 23 +++++++++++++++++++++-- >>>> tools/perf/util/pmu.h | 1 + >>>> 2 files changed, 22 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c >>>> index e215985..7e2242f 100644 >>>> --- a/tools/perf/util/pmu.c >>>> +++ b/tools/perf/util/pmu.c >>>> @@ -28,6 +28,7 @@ >>>> #include "strbuf.h" >>>> #include "fncache.h" >>>> #include "util/evsel_config.h" >>>> +#include >>>> >>>> struct perf_pmu perf_pmu__fake = { >>>> .name = "fake", >>>> @@ -875,6 +876,24 @@ static bool pmu_uncore_alias_match(const char *pmu_name, const char *name) >>>> return res; >>>> } >>>> >>>> +bool pmu_uncore_identifier_match(const char *compat, const char *id) >>>> +{ >>>> + regex_t re; >>>> + regmatch_t pmatch[1]; >>>> + int match; >>>> + >>>> + if (regcomp(&re, compat, REG_EXTENDED) != 0) { >>>> + /* Warn unable to generate match particular string. */ >>>> + pr_info("Invalid regular expression %s\n", compat); >>>> + return false; >>>> + } >>>> + >>>> + match = !regexec(&re, id, 1, pmatch, 0); >>> >>> I wonder if we can make the regular expressions like >>> "^(434|436|43c|43a)" more like "(434|436|43c|43a).*", so that we fully >>> match the id string, by here doing: >>> >>> if (match) { >>> /* Ensure a full match. */ >>> match = pmatch[0].rm_so == 0 && pmatch[0].rm_eo == strlen(id); >>> } >>> >> >> Ok, will do. >> >> >>> I think longer term we can use jevents.py to generate a pmu-events.l, >>> which would have a contents something like: >>> >>> (434|436|43c|43a).* { return PMU_....;} >>> >>> That should make the matching faster but may add some restrictions >>> onto the regular expression. >> >> Could you please describe the function of pmu-event.l in more detail? I may not fully understand it. > > So for now there's no need for a pmu-event.l, I'm fine with the code > as-is. The issue for using regular expressions is that we need to > compile (regcomp) then use them (regexec), and in this new code the > result of the parsing is discarded - perhaps we can save on some > compiling with a 1 element cache, let's wait to see performance data > saying it is an issue. If we were to compile the regular expressions > at build time with flex then the runtime cost, any caching, etc. is > unnecessary. > I see, thanks for the explanation. Thanks, Jing > Hope this makes sense. Thanks, > Ian > >> Thanks, >> Jing >> >>> >>> Thanks, >>> Ian >>> >>>> + regfree(&re); >>>> + >>>> + return match; >>>> +} >>>> + >>>> static int pmu_add_cpu_aliases_map_callback(const struct pmu_event *pe, >>>> const struct pmu_events_table *table __maybe_unused, >>>> void *vdata) >>>> @@ -915,8 +934,8 @@ static int pmu_add_sys_aliases_iter_fn(const struct pmu_event *pe, >>>> if (!pe->compat || !pe->pmu) >>>> return 0; >>>> >>>> - if (!strcmp(pmu->id, pe->compat) && >>>> - pmu_uncore_alias_match(pe->pmu, pmu->name)) { >>>> + if (pmu_uncore_alias_match(pe->pmu, pmu->name) && >>>> + pmu_uncore_identifier_match(pe->compat, pmu->id)) { >>>> perf_pmu__new_alias(pmu, >>>> pe->name, >>>> pe->desc, >>>> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h >>>> index bd5d804..fc155ce 100644 >>>> --- a/tools/perf/util/pmu.h >>>> +++ b/tools/perf/util/pmu.h >>>> @@ -240,6 +240,7 @@ void pmu_add_cpu_aliases_table(struct perf_pmu *pmu, >>>> char *perf_pmu__getcpuid(struct perf_pmu *pmu); >>>> const struct pmu_events_table *pmu_events_table__find(void); >>>> const struct pmu_metrics_table *pmu_metrics_table__find(void); >>>> +bool pmu_uncore_identifier_match(const char *compat, const char *id); >>>> >>>> int perf_pmu__convert_scale(const char *scale, char **end, double *sval); >>>> >>>> -- >>>> 1.8.3.1 >>>>