mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-08-23 23:37:42 -04:00
875a785373
Every job submission on the Steam Deck ends up walking the list of IP
blocks looking for AMD_IP_BLOCK_TYPE_SMC. Half of the call chain is like
the below, while the second half is from amdgpu_gfx_profile_ring_end_use:
amdgpu_gfx_profile_ring_begin_use
amdgpu_dpm_is_overdrive_enabled
is_support_sw_smu
amdgpu_device_ip_is_valid
On a game menu screen at 90Hz refresh rate we end up with ~840 calls per
second which sticks out when the submission worker is profiled with perf:
13.78% [kernel] [k] __lock_text_start
10.86% [kernel] [k] __lookup_object
8.76% [kernel] [k] __mod_timer
4.94% [kernel] [k] queued_spin_lock_slowpath
1.66% [kernel] [k] amdgpu_device_ip_is_valid
1.54% [kernel] [k] preempt_count_add
1.42% [kernel] [k] amdgpu_sync_peek_fence
1.18% [kernel] [k] amdgpu_vmid_grab
1.17% [kernel] [k] amdgpu_ib_schedule
1.14% [kernel] [k] kthread_worker_fn
Lets short-circuit this walk by simply caching the result of
is_support_sw_smu() in the device.
This is a micro-improvement but it is at least conceptually nicer to avoid
repeating the same walk so much.
Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>