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| author | Breno Leitao <leitao@debian.org> | 2026-08-05 07:52:36 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-08-10 11:47:20 -1000 |
| commit | a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656 (patch) | |
| tree | 39f5b258386e1127d253d293194e9a2991bf3c34 /Documentation/gpu/panthor.rst | |
| download | linux-stable-a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656.tar.gz linux-stable-a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656.zip | |
workqueue: skip the node_nr_active update for non-unbound workqueuesgrafted
apply_wqattrs_commit() updates node_nr_active->max unconditionally.
wq->node_nr_active[] is only allocated for unbound workqueues, so guard
the call before per-cpu workqueues start using this path.
No functional change: only unbound workqueues reach apply_wqattrs_*()
today.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'Documentation/gpu/panthor.rst')
| -rw-r--r-- | Documentation/gpu/panthor.rst | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/Documentation/gpu/panthor.rst b/Documentation/gpu/panthor.rst new file mode 100644 index 000000000..7a8417412 --- /dev/null +++ b/Documentation/gpu/panthor.rst @@ -0,0 +1,56 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +========================= + drm/Panthor CSF driver +========================= + +.. _panthor-usage-stats: + +Panthor DRM client usage stats implementation +============================================== + +The drm/Panthor driver implements the DRM client usage stats specification as +documented in :ref:`drm-client-usage-stats`. + +Example of the output showing the implemented key value pairs and entirety of +the currently possible format options: + +:: + pos: 0 + flags: 02400002 + mnt_id: 29 + ino: 491 + drm-driver: panthor + drm-client-id: 10 + drm-engine-panthor: 111110952750 ns + drm-cycles-panthor: 94439687187 + drm-maxfreq-panthor: 1000000000 Hz + drm-curfreq-panthor: 1000000000 Hz + panthor-resident-memory: 10396 KiB + panthor-active-memory: 10396 KiB + drm-total-memory: 16480 KiB + drm-shared-memory: 0 + drm-active-memory: 16200 KiB + drm-resident-memory: 16480 KiB + drm-purgeable-memory: 0 + +Possible `drm-engine-` key names are: `panthor`. +`drm-curfreq-` values convey the current operating frequency for that engine. + +Users must bear in mind that engine and cycle sampling are disabled by default, +because of power saving concerns. `fdinfo` users and benchmark applications which +query the fdinfo file must make sure to toggle the job profiling status of the +driver by writing into the appropriate sysfs node:: + + echo <N> > /sys/bus/platform/drivers/panthor/[a-f0-9]*.gpu/profiling + +Where `N` is a bit mask where cycle and timestamp sampling are respectively +enabled by the first and second bits. + +Possible `panthor-*-memory` keys are: `active` and `resident`. +These values convey the sizes of the internal driver-owned shmem BO's that +aren't exposed to user-space through a DRM handle, like queue ring buffers, +sync object arrays and heap chunks. Because they are all allocated and pinned +at creation time, only `panthor-resident-memory` is necessary to tell us their +size. `panthor-active-memory` shows the size of kernel BO's associated with +VM's and groups currently being scheduled for execution by the GPU. |
