| Message ID | 20220428150829.30733-2-atrajeev@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix session topology test for powerpc and add utility function to get cpuinfo entries | expand |
On 4/28/22 20:38, Athira Rajeev wrote: > /proc/cpuinfo provides information about type of processor, number > of CPU's etc. Reading /proc/cpuinfo file outputs useful information > by field name like cpu, platform, model (depending on architecture) > and its value separated by colon. > > Add new utility function "cpuinfo_field" in "util/header.c" which > accepts field name as input string to search in /proc/cpuinfo content. > This returns the first matching value as resulting string. Example, > calling the function "cpuinfo_field(platform)" in powerpc returns > the platform value. This can be used to fetch processor information > from "cpuinfo" by other utilities/testcases. > > Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> > --- > tools/perf/util/header.c | 54 ++++++++++++++++++++++++++++++++++++++++ > tools/perf/util/header.h | 1 + > 2 files changed, 55 insertions(+) > > diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c > index a27132e5a5ef..0c8dfd0c1e78 100644 > --- a/tools/perf/util/header.c > +++ b/tools/perf/util/header.c > @@ -983,6 +983,60 @@ static int write_dir_format(struct feat_fd *ff, > return do_write(ff, &data->dir.version, sizeof(data->dir.version)); > } > > +/* > + * Return entry from /proc/cpuinfo > + * indicated by "search" parameter. > + */ > +char *cpuinfo_field(const char *search) > +{ > + FILE *file; > + char *buf = NULL; > + char *copy_buf = NULL, *p; > + size_t len = 0; > + int ret = -1; > + > + if (!search) > + return NULL; > + > + file = fopen("/proc/cpuinfo", "r"); > + if (!file) > + return NULL; > + > + while (getline(&buf, &len, file) > 0) { > + ret = strncmp(buf, search, strlen(search)); > + if (!ret) > + break; Hi Athira, Do we need ret variable. Since we will come out of the loop only when we reach EOF. > + } > + > + if (ret) > + goto done; > + > + /* > + * Trim the new line and separate > + * value for search field from ":" > + * in cpuinfo line output. > + * Example output line: > + * platform : <value> > + */ > + copy_buf = buf; > + p = strchr(copy_buf, ':'); > + if (p && *(p+1) == ' ' && *(p+2)) Can you try using strim instead to remove whitespaces. This function will remove leading and trailing whitespaces from the string. > + copy_buf = p + 2; > + p = strchr(copy_buf, '\n'); do we need to replace `\n` here ? > + if (p) > + *p = '\0'; > + > + /* Copy the filtered string to buf */ > + strcpy(buf, copy_buf) You are initializing buf to NULL. So do we need to do fclose and return buf separately here? Can you move free(buf) in above condition and reuse `done` code. > + > + fclose(file); > + return buf;> + > +done: > + free(buf); > + fclose(file); > + return NULL; > +} > /* > * Check whether a CPU is online > * > diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h > index 0eb4bc29a5a4..b0f754364bd4 100644 > --- a/tools/perf/util/header.h > +++ b/tools/perf/util/header.h > @@ -166,4 +166,5 @@ int get_cpuid(char *buffer, size_t sz); > > char *get_cpuid_str(struct perf_pmu *pmu __maybe_unused); > int strcmp_cpuid_str(const char *s1, const char *s2); > +char *cpuinfo_field(const char *search); > #endif /* __PERF_HEADER_H */
> On 04-May-2022, at 7:16 PM, kajoljain <kjain@linux.ibm.com> wrote: > > > > On 4/28/22 20:38, Athira Rajeev wrote: >> /proc/cpuinfo provides information about type of processor, number >> of CPU's etc. Reading /proc/cpuinfo file outputs useful information >> by field name like cpu, platform, model (depending on architecture) >> and its value separated by colon. >> >> Add new utility function "cpuinfo_field" in "util/header.c" which >> accepts field name as input string to search in /proc/cpuinfo content. >> This returns the first matching value as resulting string. Example, >> calling the function "cpuinfo_field(platform)" in powerpc returns >> the platform value. This can be used to fetch processor information >> from "cpuinfo" by other utilities/testcases. >> >> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> >> --- >> tools/perf/util/header.c | 54 ++++++++++++++++++++++++++++++++++++++++ >> tools/perf/util/header.h | 1 + >> 2 files changed, 55 insertions(+) >> >> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c >> index a27132e5a5ef..0c8dfd0c1e78 100644 >> --- a/tools/perf/util/header.c >> +++ b/tools/perf/util/header.c >> @@ -983,6 +983,60 @@ static int write_dir_format(struct feat_fd *ff, >> return do_write(ff, &data->dir.version, sizeof(data->dir.version)); >> } >> >> +/* >> + * Return entry from /proc/cpuinfo >> + * indicated by "search" parameter. >> + */ >> +char *cpuinfo_field(const char *search) >> +{ >> + FILE *file; >> + char *buf = NULL; >> + char *copy_buf = NULL, *p; >> + size_t len = 0; >> + int ret = -1; >> + >> + if (!search) >> + return NULL; >> + >> + file = fopen("/proc/cpuinfo", "r"); >> + if (!file) >> + return NULL; >> + >> + while (getline(&buf, &len, file) > 0) { >> + ret = strncmp(buf, search, strlen(search)); >> + if (!ret) >> + break; > Hi Athira, > Do we need ret variable. Since we will come out of the loop only when > we reach EOF. > >> + } >> + >> + if (ret) >> + goto done; >> + >> + /* >> + * Trim the new line and separate >> + * value for search field from ":" >> + * in cpuinfo line output. >> + * Example output line: >> + * platform : <value> >> + */ >> + copy_buf = buf; >> + p = strchr(copy_buf, ':'); >> + if (p && *(p+1) == ' ' && *(p+2)) > > > Can you try using strim instead to remove whitespaces. This function > will remove leading and trailing whitespaces from the string. Hi Kajol, Thanks for review comments. I will send V2 addressing these changes Athira > >> + copy_buf = p + 2; >> + p = strchr(copy_buf, '\n'); > > do we need to replace `\n` here ? > > >> + if (p) >> + *p = '\0'; >> + >> + /* Copy the filtered string to buf */ >> + strcpy(buf, copy_buf) > > You are initializing buf to NULL. So do we need to do fclose and return > buf separately here? Can you move free(buf) in above condition and reuse > `done` code. >> + >> + fclose(file); >> + return buf;> + >> +done: >> + free(buf); >> + fclose(file); >> + return NULL; >> +} >> /* >> * Check whether a CPU is online >> * >> diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h >> index 0eb4bc29a5a4..b0f754364bd4 100644 >> --- a/tools/perf/util/header.h >> +++ b/tools/perf/util/header.h >> @@ -166,4 +166,5 @@ int get_cpuid(char *buffer, size_t sz); >> >> char *get_cpuid_str(struct perf_pmu *pmu __maybe_unused); >> int strcmp_cpuid_str(const char *s1, const char *s2); >> +char *cpuinfo_field(const char *search); >> #endif /* __PERF_HEADER_H */
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index a27132e5a5ef..0c8dfd0c1e78 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -983,6 +983,60 @@ static int write_dir_format(struct feat_fd *ff, return do_write(ff, &data->dir.version, sizeof(data->dir.version)); } +/* + * Return entry from /proc/cpuinfo + * indicated by "search" parameter. + */ +char *cpuinfo_field(const char *search) +{ + FILE *file; + char *buf = NULL; + char *copy_buf = NULL, *p; + size_t len = 0; + int ret = -1; + + if (!search) + return NULL; + + file = fopen("/proc/cpuinfo", "r"); + if (!file) + return NULL; + + while (getline(&buf, &len, file) > 0) { + ret = strncmp(buf, search, strlen(search)); + if (!ret) + break; + } + + if (ret) + goto done; + + /* + * Trim the new line and separate + * value for search field from ":" + * in cpuinfo line output. + * Example output line: + * platform : <value> + */ + copy_buf = buf; + p = strchr(copy_buf, ':'); + if (p && *(p+1) == ' ' && *(p+2)) + copy_buf = p + 2; + p = strchr(copy_buf, '\n'); + if (p) + *p = '\0'; + + /* Copy the filtered string to buf */ + strcpy(buf, copy_buf); + + fclose(file); + return buf; + +done: + free(buf); + fclose(file); + return NULL; +} /* * Check whether a CPU is online * diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h index 0eb4bc29a5a4..b0f754364bd4 100644 --- a/tools/perf/util/header.h +++ b/tools/perf/util/header.h @@ -166,4 +166,5 @@ int get_cpuid(char *buffer, size_t sz); char *get_cpuid_str(struct perf_pmu *pmu __maybe_unused); int strcmp_cpuid_str(const char *s1, const char *s2); +char *cpuinfo_field(const char *search); #endif /* __PERF_HEADER_H */
/proc/cpuinfo provides information about type of processor, number of CPU's etc. Reading /proc/cpuinfo file outputs useful information by field name like cpu, platform, model (depending on architecture) and its value separated by colon. Add new utility function "cpuinfo_field" in "util/header.c" which accepts field name as input string to search in /proc/cpuinfo content. This returns the first matching value as resulting string. Example, calling the function "cpuinfo_field(platform)" in powerpc returns the platform value. This can be used to fetch processor information from "cpuinfo" by other utilities/testcases. Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> --- tools/perf/util/header.c | 54 ++++++++++++++++++++++++++++++++++++++++ tools/perf/util/header.h | 1 + 2 files changed, 55 insertions(+)