From: kan.liang@linux.intel.com
To: peterz@infradead.org, mingo@redhat.com, linux-kernel@vger.kernel.org
Cc: eranian@google.com, namhyung@kernel.org, acme@kernel.org,
jolsa@redhat.com, ak@linux.intel.com,
Kan Liang <kan.liang@linux.intel.com>
Subject: [PATCH 2/7] perf: Create a symlink for a PMU
Date: Wed, 23 Jun 2021 18:22:04 -0700 [thread overview]
Message-ID: <1624497729-158864-3-git-send-email-kan.liang@linux.intel.com> (raw)
In-Reply-To: <1624497729-158864-1-git-send-email-kan.liang@linux.intel.com>
From: Kan Liang <kan.liang@linux.intel.com>
A perf PMU may have two PMU names. For example, Intel Sapphire Rapids
server supports the discovery mechanism. Without the platform-specific
support, an uncore PMU is named by a type ID plus a box ID, e.g.,
uncore_type_0_0, because the real name of the uncore PMU cannot be
retrieved from the discovery table. With the platform-specific support
later, perf has the mapping information from a type ID to a specific
uncore unit. Just like the previous platforms, the uncore PMU will be
named by the real PMU name, e.g., uncore_cha_0. The user scripts which
work well with the old name may not work anymore. To avoid the issue, a
symlink should be created from the new to the old name.
The perf PMU devices are created under /sys/bus/event_source/devices/.
The symlink should be created in the same directory to facilitate the
perf tool.
Add a new variable, link_name, to store the new name of a PMU. Link it
to the old name if applies.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
include/linux/perf_event.h | 1 +
kernel/events/core.c | 19 +++++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f5a6a2f..c8a3388 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -284,6 +284,7 @@ struct pmu {
const struct attribute_group **attr_groups;
const struct attribute_group **attr_update;
const char *name;
+ const char *link_name;
int type;
/*
diff --git a/kernel/events/core.c b/kernel/events/core.c
index f0cc8e5..b6024f6 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10952,6 +10952,16 @@ static struct bus_type pmu_bus = {
static void pmu_dev_release(struct device *dev)
{
+ struct pmu *pmu = dev_get_drvdata(dev);
+
+ if (pmu && pmu->link_name) {
+ struct kset *devices_kset;
+
+ devices_kset = bus_get_devices_kset(pmu->dev->bus);
+ if (devices_kset)
+ sysfs_remove_link(&devices_kset->kobj, pmu->link_name);
+ }
+
kfree(dev);
}
@@ -10989,6 +10999,15 @@ static int pmu_dev_alloc(struct pmu *pmu)
if (ret)
goto del_dev;
+ if (pmu->link_name) {
+ struct kset *devices_kset;
+
+ devices_kset = bus_get_devices_kset(pmu->dev->bus);
+ if (devices_kset)
+ ret = sysfs_create_link(&devices_kset->kobj,
+ &pmu->dev->kobj,
+ pmu->link_name);
+ }
out:
return ret;
--
2.7.4
next prev parent reply other threads:[~2021-06-24 1:37 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-24 1:22 [PATCH 0/7] perf: Add Sapphire Rapids server uncore support kan.liang
2021-06-24 1:22 ` [PATCH 1/7] driver core: Add a way to get to bus devices kset kan.liang
2021-06-24 5:41 ` Greg KH
2021-06-24 1:22 ` kan.liang [this message]
2021-06-24 5:48 ` [PATCH 2/7] perf: Create a symlink for a PMU Greg KH
2021-06-24 14:24 ` Andi Kleen
2021-06-24 14:29 ` Greg KH
2021-06-24 15:24 ` Andi Kleen
2021-06-24 15:31 ` Greg KH
2021-06-24 17:07 ` Liang, Kan
2021-06-24 17:35 ` Greg KH
2021-06-24 17:49 ` Andi Kleen
2021-06-25 5:18 ` Greg KH
2021-06-25 5:17 ` Greg KH
2021-06-24 17:28 ` Andi Kleen
2021-06-25 5:19 ` Greg KH
2021-06-25 14:22 ` Andi Kleen
2021-06-25 14:38 ` Greg KH
2021-06-25 14:49 ` Andi Kleen
2021-06-25 15:03 ` Liang, Kan
2021-06-25 15:44 ` Andi Kleen
2021-06-25 15:57 ` Liang, Kan
2021-06-25 16:18 ` Liang, Kan
2021-06-27 11:02 ` Greg KH
2021-06-27 16:30 ` Andi Kleen
2021-06-28 6:55 ` Greg KH
2021-06-28 15:00 ` Andi Kleen
2021-06-24 1:22 ` [PATCH 3/7] perf/x86/intel/uncore: Create a symlink for an uncore PMU kan.liang
2021-06-24 5:44 ` Greg KH
2021-06-24 1:22 ` [PATCH 4/7] perf/x86/intel/uncore: Add Sapphire Rapids server support kan.liang
2021-06-24 1:22 ` [PATCH 5/7] perf/x86/intel/uncore: Factor out snr_uncore_mmio_map() kan.liang
2021-06-24 1:22 ` [PATCH 6/7] perf/x86/intel/uncore: Support free-running counters on Sapphire Rapids server kan.liang
2021-06-24 1:22 ` [PATCH 7/7] perf/x86/intel/uncore: Fix invalid unit check kan.liang
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