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 C0D07C4332F for ; Fri, 3 Nov 2023 10:00:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347607AbjKCKAJ (ORCPT ); Fri, 3 Nov 2023 06:00:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347416AbjKCKAH (ORCPT ); Fri, 3 Nov 2023 06:00:07 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 17396191; Fri, 3 Nov 2023 03:00:01 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 54DE02F4; Fri, 3 Nov 2023 03:00:43 -0700 (PDT) Received: from [192.168.1.3] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5A2FF3F64C; Fri, 3 Nov 2023 02:59:59 -0700 (PDT) Message-ID: <663f6b75-4346-4007-32dc-50eca444a4ef@arm.com> Date: Fri, 3 Nov 2023 09:59:58 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH] perf test: Simplify object code reading test Content-Language: en-US To: Namhyung Kim , Arnaldo Carvalho de Melo , Jiri Olsa Cc: Ian Rogers , Adrian Hunter , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org, Thomas Richter References: <20231102234013.4188687-1-namhyung@kernel.org> From: James Clark In-Reply-To: <20231102234013.4188687-1-namhyung@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/11/2023 23:40, Namhyung Kim wrote: > It tries cycles (or cpu-clock on s390) event with exclude_kernel bit to > open. But other arch on a VM can fail with the hardware event and need > to fallback to the software event in the same way. > > So let's get rid of the cpuid check and use generic fallback mechanism > using an array of event candidates. Now event in the odd index excludes > the kernel so use that for the return value. > > Cc: Thomas Richter > Signed-off-by: Namhyung Kim > --- > tools/perf/tests/code-reading.c | 76 ++++++++++----------------------- > 1 file changed, 23 insertions(+), 53 deletions(-) > Tested-by: James Clark > diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c > index 3af81012014e..047ba297c6fa 100644 > --- a/tools/perf/tests/code-reading.c > +++ b/tools/perf/tests/code-reading.c > @@ -511,38 +511,6 @@ static void fs_something(void) > } > } > > -#ifdef __s390x__ > -#include "header.h" // for get_cpuid() > -#endif > - > -static const char *do_determine_event(bool excl_kernel) > -{ > - const char *event = excl_kernel ? "cycles:u" : "cycles"; > - > -#ifdef __s390x__ > - char cpuid[128], model[16], model_c[16], cpum_cf_v[16]; > - unsigned int family; > - int ret, cpum_cf_a; > - > - if (get_cpuid(cpuid, sizeof(cpuid))) > - goto out_clocks; > - ret = sscanf(cpuid, "%*[^,],%u,%[^,],%[^,],%[^,],%x", &family, model_c, > - model, cpum_cf_v, &cpum_cf_a); > - if (ret != 5) /* Not available */ > - goto out_clocks; > - if (excl_kernel && (cpum_cf_a & 4)) > - return event; > - if (!excl_kernel && (cpum_cf_a & 2)) > - return event; > - > - /* Fall through: missing authorization */ > -out_clocks: > - event = excl_kernel ? "cpu-clock:u" : "cpu-clock"; > - > -#endif > - return event; > -} > - > static void do_something(void) > { > fs_something(); > @@ -583,8 +551,10 @@ static int do_test_code_reading(bool try_kcore) > int err = -1, ret; > pid_t pid; > struct map *map; > - bool have_vmlinux, have_kcore, excl_kernel = false; > + bool have_vmlinux, have_kcore; > struct dso *dso; > + const char *events[] = { "cycles", "cycles:u", "cpu-clock", "cpu-clock:u", NULL }; > + int evidx = 0; > > pid = getpid(); > > @@ -618,7 +588,7 @@ static int do_test_code_reading(bool try_kcore) > > /* No point getting kernel events if there is no kernel object */ > if (!have_vmlinux && !have_kcore) > - excl_kernel = true; > + evidx++; > > threads = thread_map__new_by_tid(pid); > if (!threads) { > @@ -646,7 +616,7 @@ static int do_test_code_reading(bool try_kcore) > goto out_put; > } > > - while (1) { > + while (events[evidx]) { > const char *str; > > evlist = evlist__new(); > @@ -657,7 +627,7 @@ static int do_test_code_reading(bool try_kcore) > > perf_evlist__set_maps(&evlist->core, cpus, threads); > > - str = do_determine_event(excl_kernel); > + str = events[evidx]; > pr_debug("Parsing event '%s'\n", str); > ret = parse_event(evlist, str); > if (ret < 0) { > @@ -675,32 +645,32 @@ static int do_test_code_reading(bool try_kcore) > > ret = evlist__open(evlist); > if (ret < 0) { > - if (!excl_kernel) { > - excl_kernel = true; > - /* > - * Both cpus and threads are now owned by evlist > - * and will be freed by following perf_evlist__set_maps > - * call. Getting reference to keep them alive. > - */ > - perf_cpu_map__get(cpus); > - perf_thread_map__get(threads); > - perf_evlist__set_maps(&evlist->core, NULL, NULL); > - evlist__delete(evlist); > - evlist = NULL; > - continue; > - } > + evidx++; > > - if (verbose > 0) { > + if (events[evidx] == NULL && verbose > 0) { > char errbuf[512]; > evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf)); > pr_debug("perf_evlist__open() failed!\n%s\n", errbuf); > } > > - goto out_put; > + /* > + * Both cpus and threads are now owned by evlist > + * and will be freed by following perf_evlist__set_maps > + * call. Getting reference to keep them alive. > + */ > + perf_cpu_map__get(cpus); > + perf_thread_map__get(threads); > + perf_evlist__set_maps(&evlist->core, NULL, NULL); > + evlist__delete(evlist); > + evlist = NULL; > + continue; > } > break; > } > > + if (events[evidx] == NULL) > + goto out_put; > + > ret = evlist__mmap(evlist, UINT_MAX); > if (ret < 0) { > pr_debug("evlist__mmap failed\n"); > @@ -721,7 +691,7 @@ static int do_test_code_reading(bool try_kcore) > err = TEST_CODE_READING_NO_KERNEL_OBJ; > else if (!have_vmlinux && !try_kcore) > err = TEST_CODE_READING_NO_VMLINUX; > - else if (excl_kernel) > + else if (evidx % 2) > err = TEST_CODE_READING_NO_ACCESS; > else > err = TEST_CODE_READING_OK;