Commit f3a3a825 authored May 12, 2019 by Jiri Olsa Committed by Ingo Molnar Jun 03, 2019

perf/core: Add attr_groups_update into struct pmu



Adding attr_update attribute group into pmu, to allow
having multiple attribute groups for same group name.

This will allow us to update "events" or "format"
directories with attributes that depend on various
HW conditions.

For example having group_format_extra group that updates
"format" directory only if pmu version is 2 and higher:

  static umode_t
  exra_is_visible(struct kobject *kobj, struct attribute *attr, int i)
  {
         return x86_pmu.version >= 2 ? attr->mode : 0;
  }

  static struct attribute_group group_format_extra = {
         .name       = "format",
         .is_visible = exra_is_visible,
  };

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190512155518.21468-3-jolsa@kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent aac1f7f9

include/linux/perf_event.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -255,6 +255,7 @@ struct pmu {
		struct module *module;
		struct device *dev;
		const struct attribute_group **attr_groups;
		const struct attribute_group **attr_update;
		const char *name;
		int type;

kernel/events/core.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -9874,6 +9874,12 @@ static int pmu_dev_alloc(struct pmu *pmu)
		if (ret)
		goto del_dev;

		if (pmu->attr_update)
		ret = sysfs_update_groups(&pmu->dev->kobj, pmu->attr_update);

		if (ret)
		goto del_dev;

		out:
		return ret;

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