Messages in this thread | | | Subject | Re: [PATCH 1/2] perf vendor events: Add stepping in CPUID string for x86 | From | "Liang, Kan" <> | Date | Thu, 15 Nov 2018 09:26:50 -0500 |
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On 11/15/2018 8:53 AM, Jiri Olsa wrote: > On Wed, Nov 14, 2018 at 01:24:15PM -0800, kan.liang@linux.intel.com wrote: > > SNIP > >> diff --git a/tools/perf/arch/x86/util/header.c b/tools/perf/arch/x86/util/header.c >> index fb0d71afee8b..b428a4b00bf7 100644 >> --- a/tools/perf/arch/x86/util/header.c >> +++ b/tools/perf/arch/x86/util/header.c >> @@ -4,6 +4,7 @@ >> #include <stdio.h> >> #include <stdlib.h> >> #include <string.h> >> +#include <regex.h> >> >> #include "../../util/header.h" >> >> @@ -70,9 +71,73 @@ get_cpuid_str(struct perf_pmu *pmu __maybe_unused) >> { >> char *buf = malloc(128); >> >> - if (buf && __get_cpuid(buf, 128, "%s-%u-%X$") < 0) { >> + if (buf && __get_cpuid(buf, 128, "%s-%u-%X-%X$") < 0) { >> free(buf); >> return NULL; >> } >> return buf; >> } >> + >> +/* Full CPUID format for x86 is vendor-family-model-stepping */ >> +static bool is_full_cpuid(const char *cpuid) >> +{ >> + const char *tmp = cpuid; >> + int count = 0; >> + >> + while ((tmp = strchr(tmp, '-')) != NULL) { >> + count++; >> + tmp++; >> + } >> + >> + if (count == 3) >> + return true; >> + >> + return false; >> +} >> + >> +int strcmp_cpuid_str(const char *mapcpuid, const char *cpuid) >> +{ >> + regex_t re; >> + regmatch_t pmatch[1]; >> + int match; >> + bool full_mapcpuid = is_full_cpuid(mapcpuid); >> + bool full_cpuid = is_full_cpuid(cpuid); > > cpuid will be always full from now right? why do we need to check it? >
User may set cpuid by environment string "PERF_CPUID", which may not be full format.
> also please move this to arch/x86/util/pmu.c > so it matches the weak function object
Sure.
> >> + >> + /* >> + * Full CPUID format is required to identify a platform. >> + * Error out if the cpuid string is incomplete. >> + */ >> + if (full_mapcpuid && !full_cpuid) { >> + pr_info("Invalid CPUID %s. Full CPUID is required, " >> + "vendor-family-model-stepping\n", cpuid); >> + return 1; >> + } >> + >> + if (regcomp(&re, mapcpuid, REG_EXTENDED) != 0) { >> + /* Warn unable to generate match particular string. */ >> + pr_info("Invalid regular expression %s\n", mapcpuid); >> + return 1; >> + } >> + >> + match = !regexec(&re, cpuid, 1, pmatch, 0); >> + regfree(&re); >> + if (match) { >> + size_t match_len = (pmatch[0].rm_eo - pmatch[0].rm_so); >> + size_t cpuid_len; >> + >> + /* If the full CPUID format isn't required, >> + * ignoring the stepping. >> + */ >> + if (!full_mapcpuid && full_cpuid) >> + cpuid_len = strrchr(cpuid, '-') - cpuid; >> + else >> + cpuid_len = strlen(cpuid); >> + >> + >> + /* Verify the entire string matched. */ >> + if (match_len == cpuid_len) >> + return 0; > > why is this necessary? >
It's from previous common code. As my understanding, it just double check the matched strings. There is no harmful. So I keep it.
Thanks, Kan
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