/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 <atraj...@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;
+ }
+
+ 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 */
--
2.35.1
