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[AMD Official Use Only - AMD Internal Distribution Only]
This is not a request from a customer. It is surfaced to improve SVM performance especially for non-HIP workloads.
Regards, Ramesh
From: Chen, Xiaogang <Xiaogang.Chen@xxxxxxx>
Sent: Friday, August 30, 2024 4:01 AM To: Errabolu, Ramesh <Ramesh.Errabolu@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx <amd-gfx@xxxxxxxxxxxxxxxxxxxxx> Subject: Re: [PATCH V3] drm/amdgpu: Surface svm_default_granularity, a RW module parameter On 8/29/2024 5:13 PM, Ramesh Errabolu wrote: > Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding. > > > Enables users to update SVM's default granularity, used in > buffer migration and handling of recoverable page faults. > Param value is set in terms of log(numPages(buffer)), > e.g. 9 for a 2 MIB buffer Forgot asking if this parameter is request from customer or used for debug/experiment purpose? If it is later, how about put it at debug fs? There are already many driver parameters. Regards Xiaogang > Signed-off-by: Ramesh Errabolu <Ramesh.Errabolu@xxxxxxx> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 + > drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 17 +++++++++++++++++ > drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 6 ++++++ > drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 25 +++++++++++++++---------- > 4 files changed, 39 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h > index e8c284aea1f2..8eb934af02f2 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h > @@ -237,6 +237,7 @@ extern int sched_policy; > extern bool debug_evictions; > extern bool no_system_mem_limit; > extern int halt_if_hws_hang; > +extern uint amdgpu_svm_default_granularity; > #else > static const int __maybe_unused sched_policy = KFD_SCHED_POLICY_HWS; > static const bool __maybe_unused debug_evictions; /* = false */ > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > index b9529948f2b2..442039436cb3 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > @@ -169,6 +169,16 @@ uint amdgpu_sdma_phase_quantum = 32; > char *amdgpu_disable_cu; > char *amdgpu_virtual_display; > bool enforce_isolation; > + > +/* Specifies the default granularity for SVM, used in buffer > + * migration and restoration of backing memory when handling > + * recoverable page faults. > + * > + * The value is given as log(numPages(buffer)); for a 2 MiB > + * buffer it computes to be 9 > + */ > +uint amdgpu_svm_default_granularity = 9; > + > /* > * OverDrive(bit 14) disabled by default > * GFX DCS(bit 19) disabled by default > @@ -320,6 +330,13 @@ module_param_named(pcie_gen2, amdgpu_pcie_gen2, int, 0444); > MODULE_PARM_DESC(msi, "MSI support (1 = enable, 0 = disable, -1 = auto)"); > module_param_named(msi, amdgpu_msi, int, 0444); > > +/** > + * DOC: svm_default_granularity (uint) > + * Used in buffer migration and handling of recoverable page faults > + */ > +MODULE_PARM_DESC(svm_default_granularity, "SVM's default granularity in log(2^Pages), default 9 = 2^9 = 2 MiB"); > +module_param_named(svm_default_granularity, amdgpu_svm_default_granularity, uint, 0644); > + > /** > * DOC: lockup_timeout (string) > * Set GPU scheduler timeout value in ms. > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h > index 9ae9abc6eb43..d6530febabad 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h > @@ -868,6 +868,12 @@ struct svm_range_list { > struct task_struct *faulting_task; > /* check point ts decides if page fault recovery need be dropped */ > uint64_t checkpoint_ts[MAX_GPU_INSTANCE]; > + > + /* Default granularity to use in buffer migration > + * and restoration of backing memory while handling > + * recoverable page faults > + */ > + uint8_t default_granularity; > }; > > /* Process data */ > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c > index b44dec90969f..624bfe317c9c 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c > @@ -309,12 +309,13 @@ static void svm_range_free(struct svm_range *prange, bool do_unmap) > } > > static void > -svm_range_set_default_attributes(int32_t *location, int32_t *prefetch_loc, > - uint8_t *granularity, uint32_t *flags) > +svm_range_set_default_attributes(struct svm_range_list *svms, > + int32_t *location, uint8_t *granularity, > + int32_t *prefetch_loc, uint32_t *flags) > { > *location = KFD_IOCTL_SVM_LOCATION_UNDEFINED; > *prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED; > - *granularity = 9; > + *granularity = svms->default_granularity; > *flags = > KFD_IOCTL_SVM_FLAG_HOST_ACCESS | KFD_IOCTL_SVM_FLAG_COHERENT; > } > @@ -358,9 +359,8 @@ svm_range *svm_range_new(struct svm_range_list *svms, uint64_t start, > bitmap_copy(prange->bitmap_access, svms->bitmap_supported, > MAX_GPU_INSTANCE); > > - svm_range_set_default_attributes(&prange->preferred_loc, > - &prange->prefetch_loc, > - &prange->granularity, &prange->flags); > + svm_range_set_default_attributes(svms, &prange->preferred_loc, > + &prange->granularity, &prange->prefetch_loc, &prange->flags); > > pr_debug("svms 0x%p [0x%llx 0x%llx]\n", svms, start, last); > > @@ -2694,9 +2694,10 @@ svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr, > *is_heap_stack = vma_is_initial_heap(vma) || vma_is_initial_stack(vma); > > start_limit = max(vma->vm_start >> PAGE_SHIFT, > - (unsigned long)ALIGN_DOWN(addr, 2UL << 8)); > + (unsigned long)ALIGN_DOWN(addr, 1UL << p->svms.default_granularity)); > end_limit = min(vma->vm_end >> PAGE_SHIFT, > - (unsigned long)ALIGN(addr + 1, 2UL << 8)); > + (unsigned long)ALIGN(addr + 1, 1UL << p->svms.default_granularity)); > + > /* First range that starts after the fault address */ > node = interval_tree_iter_first(&p->svms.objects, addr + 1, ULONG_MAX); > if (node) { > @@ -3240,6 +3241,10 @@ int svm_range_list_init(struct kfd_process *p) > if (KFD_IS_SVM_API_SUPPORTED(p->pdds[i]->dev->adev)) > bitmap_set(svms->bitmap_supported, i, 1); > > + /* Update default granularity to one bound by user/driver */ > + svms->default_granularity = min_t(u8, amdgpu_svm_default_granularity, 0x1B); > + pr_debug("Default SVM Granularity to use: %d\n", svms->default_granularity); > + > return 0; > } > > @@ -3767,8 +3772,8 @@ svm_range_get_attr(struct kfd_process *p, struct mm_struct *mm, > node = interval_tree_iter_first(&svms->objects, start, last); > if (!node) { > pr_debug("range attrs not found return default values\n"); > - svm_range_set_default_attributes(&location, &prefetch_loc, > - &granularity, &flags_and); > + svm_range_set_default_attributes(svms, &location, > + &granularity, &prefetch_loc, &flags_and); > flags_or = flags_and; > if (p->xnack_enabled) > bitmap_copy(bitmap_access, svms->bitmap_supported, > -- > 2.34.1 > |
