On 2026. június 26., péntek 10:55:57 közép-európai nyári idő Tvrtko Ursulin wrote: > 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.
Hi, I agree with cleaning up this thing. Reviewed-by: Timur Kristóf <[email protected]> That being said, I think is_support_sw_smu() is horrible and should be removed alltogether, because it goes against how the rest of the power management code works. In my opinion, we should instead: 1. Hook up some function pointers and check those instead, For example in amdgpu_pm_acpi_event_handler() we should just hook up smu_set_ac_dc() to the notify_ac_dc() function pointer. There are plenty of other similar cases. Another example, for amdgpu_dpm_mode1_reset() we should introduce a new asic_reset_mode_1() pointer in amd_pm_funcs() similar to how it works with MODE2 reset for consistency. 2. Eliminate redundant functions where the same thing is already done elsewhere. For example in amdgpu_dpm_is_mode1_reset_supported() it checks smu_mode1_reset_is_support() which is redundant because the supported reset type is available on the ASIC functions already and we can just use that. What do you think? Thanks & best regards, Timur > > Signed-off-by: Tvrtko Ursulin <[email protected]> > Cc: Alex Deucher <[email protected]> > Cc: Christian König <[email protected]> > Cc: Timur Kristóf <[email protected]> > --- > v2: > * Approach changed to cache sw_smu status only. > --- > drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 + > drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 3 +++ > drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c | 14 +++++--------- > drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h | 8 +++++++- > 4 files changed, 16 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h > b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7b09410d6d8f..9803967d15f9 > 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h > @@ -851,6 +851,7 @@ struct amdgpu_device { > struct dev_pm_domain vga_pm_domain; > bool have_disp_power_ref; > bool have_atomics_support; > + bool is_sw_smu; > > /* BIOS */ > bool is_atom_fw; > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index > 1e6b75ecafe4..7f935a5778b0 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > @@ -74,6 +74,7 @@ > #include "amdgpu_ras.h" > #include "amdgpu_ras_mgr.h" > #include "amdgpu_pmu.h" > +#include "amdgpu_smu.h" > #include "amdgpu_fru_eeprom.h" > #include "amdgpu_reset.h" > #include "amdgpu_virt.h" > @@ -2130,6 +2131,8 @@ static int amdgpu_device_ip_early_init(struct > amdgpu_device *adev) adev->cg_flags &= amdgpu_cg_mask; > adev->pg_flags &= amdgpu_pg_mask; > > + amdgpu_smu_early_init(adev); > + > return 0; > } > > diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c > b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c index > 208a2fba6d40..82c9ae6a5092 100644 > --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c > +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c > @@ -591,17 +591,13 @@ static int smu_get_power_num_states(void *handle, > return 0; > } > > -bool is_support_sw_smu(struct amdgpu_device *adev) > +void amdgpu_smu_early_init(struct amdgpu_device *adev) > { > /* vega20 is 11.0.2, but it's supported via the powerplay code */ > - if (adev->asic_type == CHIP_VEGA20) > - return false; > - > - if ((amdgpu_ip_version(adev, MP1_HWIP, 0) >= IP_VERSION(11, 0, 0)) && > - amdgpu_device_ip_is_valid(adev, AMD_IP_BLOCK_TYPE_SMC)) > - return true; > - > - return false; > + adev->is_sw_smu = adev->asic_type != CHIP_VEGA20 && > + (amdgpu_ip_version(adev, MP1_HWIP, 0) >= > + IP_VERSION(11, 0, 0) && > + amdgpu_device_ip_is_valid(adev, AMD_IP_BLOCK_TYPE_SMC)); > } > > bool is_support_cclk_dpm(struct amdgpu_device *adev) > diff --git a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h > b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h index > d76e0b005308..efc52d97058b 100644 > --- a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h > +++ b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h > @@ -1952,7 +1952,13 @@ int smu_link_reset(struct smu_context *smu); > > extern const struct amd_ip_funcs smu_ip_funcs; > > -bool is_support_sw_smu(struct amdgpu_device *adev); > +void amdgpu_smu_early_init(struct amdgpu_device *adev); > + > +static inline bool is_support_sw_smu(struct amdgpu_device *adev) > +{ > + return adev->is_sw_smu; > +} > + > bool is_support_cclk_dpm(struct amdgpu_device *adev); > int smu_write_watermarks_table(struct smu_context *smu);
