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Commit 14b22ae0 authored by Ganapatrao Kulkarni's avatar Ganapatrao Kulkarni Committed by Arnaldo Carvalho de Melo
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perf pmu: Add helper function is_pmu_core to detect PMU CORE devices 



On some platforms, PMU core devices sysfs name is not cpu.
Adding function is_pmu_core to detect PMU core devices using
core device specific hints in sysfs.

For arm64 platforms, all core devices have file "cpus" in sysfs.

Signed-off-by: default avatarGanapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
Tested-by: default avatarShaokun Zhang <zhangshaokun@hisilicon.com>
Tested-by: default avatarJin Yao <yao.jin@linux.intel.com>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/n/tip-y1woxt1k2pqqwpprhonnft2s@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent b57df288

tools/perf/util/pmu.c

+35 −4
Original line number Diff line number Diff line
@@ -536,6 +536,34 @@ static bool pmu_is_uncore(const char *name) 
	return !!cpus;

}



/*

 *  PMU CORE devices have different name other than cpu in sysfs on some

 *  platforms. looking for possible sysfs files to identify as core device.

 */

static int is_pmu_core(const char *name)

{

	struct stat st;

	char path[PATH_MAX];

	const char *sysfs = sysfs__mountpoint();



	if (!sysfs)

		return 0;



	/* Look for cpu sysfs (x86 and others) */

	scnprintf(path, PATH_MAX, "%s/bus/event_source/devices/cpu", sysfs);

	if ((stat(path, &st) == 0) &&

			(strncmp(name, "cpu", strlen("cpu")) == 0))

		return 1;



	/* Look for cpu sysfs (specific to arm) */

	scnprintf(path, PATH_MAX, "%s/bus/event_source/devices/%s/cpus",

				sysfs, name);

	if (stat(path, &st) == 0)

		return 1;



	return 0;

}



/*

 * Return the CPU id as a raw string.

 *
@@ -609,7 +637,6 @@ static void pmu_add_cpu_aliases(struct list_head *head, struct perf_pmu *pmu) 
	 */

	i = 0;

	while (1) {

		const char *pname;



		pe = &map->table[i++];

		if (!pe->name) {
@@ -618,9 +645,13 @@ static void pmu_add_cpu_aliases(struct list_head *head, struct perf_pmu *pmu) 
			break;

		}



		pname = pe->pmu ? pe->pmu : "cpu";

		if (strncmp(pname, name, strlen(pname)))

		if (!is_pmu_core(name)) {

			/* check for uncore devices */

			if (pe->pmu == NULL)

				continue;

			if (strncmp(pe->pmu, name, strlen(pe->pmu)))

				continue;

		}



		/* need type casts to override 'const' */

		__perf_pmu__new_alias(head, NULL, (char *)pe->name,