Re: 回复: [PATCH v2] drm/amdgpu: Put drm_dev_enter/exit outside hot codepath
Andrey Grodzovsky
andrey.grodzovsky at amd.com
Wed Sep 15 13:52:40 UTC 2021
On 2021-09-15 2:42 a.m., Pan, Xinhui wrote:
> [AMD Official Use Only]
>
> Andrey
> I hit panic with this plug/unplug test without this patch.
Can you please tell which ASIC you are using and which kernel branch and
what is the tip commit ?
> But as we add enter/exit in all its callers. maybe it would not impact plug/unplug.
If you add enter/exit in all callers then why this solves the problem ?
Is it because in one or more callers
amdgpu_gmc_set_pte_pde is called many times and so calling enter/exit
many times creates the problematic
contention from multiple threads ?
Andrey
>
> [ 1109.041095] BUG: unable to handle page fault for address: 00000000000010e1
> [ 1109.086353] RIP: 0010:vega10_power_gate_vce+0x15/0x40 [amdgpu]
> [ 1109.196706] Call Trace:
> [ 1109.199374] ? pp_set_powergating_by_smu+0x1f9/0x4a0 [amdgpu]
> [ 1109.205843] amdgpu_dpm_set_powergating_by_smu+0xa6/0x150 [amdgpu]
> [ 1109.212776] amdgpu_dpm_enable_vce+0x36/0x100 [amdgpu]
> [ 1109.218563] vce_v4_0_hw_fini+0xe1/0xf0 [amdgpu]
> [ 1109.223747] amdgpu_device_fini_hw+0x333/0x483 [amdgpu]
> [ 1109.229650] amdgpu_driver_unload_kms+0x80/0xe0 [amdgpu]
> [ 1109.235577] amdgpu_pci_remove+0x37/0x70 [amdgpu]
> [ 1109.240853] pci_device_remove+0x3b/0xb0
> [ 1109.245127] device_release_driver_internal+0x100/0x1d0
> [ 1109.250857] device_release_driver+0x12/0x20
> [ 1109.255535] pci_stop_bus_device+0x79/0xa0
> [ 1109.260016] pci_stop_and_remove_bus_device_locked+0x1b/0x30
> [ 1109.266197] remove_store+0x7b/0x90
> [ 1109.269990] dev_attr_store+0x14/0x30
> [ 1109.274002] sysfs_kf_write+0x48/0x60
> [ 1109.277998] kernfs_fop_write_iter+0x14e/0x1e0
>
> ________________________________________
> 发件人: Pan, Xinhui <Xinhui.Pan at amd.com>
> 发送时间: 2021年9月15日 14:37
> 收件人: amd-gfx at lists.freedesktop.org
> 抄送: Deucher, Alexander; Koenig, Christian; Grodzovsky, Andrey; Pan, Xinhui
> 主题: [PATCH v2] drm/amdgpu: Put drm_dev_enter/exit outside hot codepath
>
> We hit soft hang while doing memory pressure test on one numa system.
> After a qucik look, this is because kfd invalid/valid userptr memory
> frequently with process_info lock hold.
> Looks like update page table mapping use too much cpu time.
>
> perf top says below,
> 75.81% [kernel] [k] __srcu_read_unlock
> 6.19% [amdgpu] [k] amdgpu_gmc_set_pte_pde
> 3.56% [kernel] [k] __srcu_read_lock
> 2.20% [amdgpu] [k] amdgpu_vm_cpu_update
> 2.20% [kernel] [k] __sg_page_iter_dma_next
> 2.15% [drm] [k] drm_dev_enter
> 1.70% [drm] [k] drm_prime_sg_to_dma_addr_array
> 1.18% [kernel] [k] __sg_alloc_table_from_pages
> 1.09% [drm] [k] drm_dev_exit
>
> So move drm_dev_enter/exit outside gmc code, instead let caller do it.
> They are gart_unbind, gart_map, vm_clear_bo, vm_update_pdes and
> gmc_init_pdb0. vm_bo_update_mapping already calls it.
>
> Signed-off-by: xinhui pan <xinhui.pan at amd.com>
> ---
> change from v1:
> add enter/exit in more gmc_set_pte_pde callers
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c | 11 ++++++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c | 11 +++++-----
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 28 +++++++++++++++++-------
> 3 files changed, 36 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> index 76efd5f8950f..d7e4f4660acf 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> @@ -34,6 +34,7 @@
> #include <asm/set_memory.h>
> #endif
> #include "amdgpu.h"
> +#include <drm/drm_drv.h>
>
> /*
> * GART
> @@ -230,12 +231,16 @@ int amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
> u64 page_base;
> /* Starting from VEGA10, system bit must be 0 to mean invalid. */
> uint64_t flags = 0;
> + int idx;
>
> if (!adev->gart.ready) {
> WARN(1, "trying to unbind memory from uninitialized GART !\n");
> return -EINVAL;
> }
>
> + if (!drm_dev_enter(&adev->ddev, &idx))
> + return 0;
> +
> t = offset / AMDGPU_GPU_PAGE_SIZE;
> p = t / AMDGPU_GPU_PAGES_IN_CPU_PAGE;
> for (i = 0; i < pages; i++, p++) {
> @@ -254,6 +259,7 @@ int amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
> for (i = 0; i < adev->num_vmhubs; i++)
> amdgpu_gmc_flush_gpu_tlb(adev, 0, i, 0);
>
> + drm_dev_exit(idx);
> return 0;
> }
>
> @@ -276,12 +282,16 @@ int amdgpu_gart_map(struct amdgpu_device *adev, uint64_t offset,
> {
> uint64_t page_base;
> unsigned i, j, t;
> + int idx;
>
> if (!adev->gart.ready) {
> WARN(1, "trying to bind memory to uninitialized GART !\n");
> return -EINVAL;
> }
>
> + if (!drm_dev_enter(&adev->ddev, &idx))
> + return 0;
> +
> t = offset / AMDGPU_GPU_PAGE_SIZE;
>
> for (i = 0; i < pages; i++) {
> @@ -291,6 +301,7 @@ int amdgpu_gart_map(struct amdgpu_device *adev, uint64_t offset,
> page_base += AMDGPU_GPU_PAGE_SIZE;
> }
> }
> + drm_dev_exit(idx);
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> index 54f059501a33..1427fd70310c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> @@ -153,10 +153,6 @@ int amdgpu_gmc_set_pte_pde(struct amdgpu_device *adev, void *cpu_pt_addr,
> {
> void __iomem *ptr = (void *)cpu_pt_addr;
> uint64_t value;
> - int idx;
> -
> - if (!drm_dev_enter(&adev->ddev, &idx))
> - return 0;
>
> /*
> * The following is for PTE only. GART does not have PDEs.
> @@ -165,8 +161,6 @@ int amdgpu_gmc_set_pte_pde(struct amdgpu_device *adev, void *cpu_pt_addr,
> value |= flags;
> writeq(value, ptr + (gpu_page_idx * 8));
>
> - drm_dev_exit(idx);
> -
> return 0;
> }
>
> @@ -752,6 +746,10 @@ void amdgpu_gmc_init_pdb0(struct amdgpu_device *adev)
> adev->gmc.xgmi.physical_node_id * adev->gmc.xgmi.node_segment_size;
> u64 vram_end = vram_addr + vram_size;
> u64 gart_ptb_gpu_pa = amdgpu_gmc_vram_pa(adev, adev->gart.bo);
> + int idx;
> +
> + if (!drm_dev_enter(&adev->ddev, &idx))
> + return;
>
> flags |= AMDGPU_PTE_VALID | AMDGPU_PTE_READABLE;
> flags |= AMDGPU_PTE_WRITEABLE;
> @@ -773,6 +771,7 @@ void amdgpu_gmc_init_pdb0(struct amdgpu_device *adev)
> flags |= AMDGPU_PDE_BFS(0) | AMDGPU_PTE_SNOOPED;
> /* Requires gart_ptb_gpu_pa to be 4K aligned */
> amdgpu_gmc_set_pte_pde(adev, adev->gmc.ptr_pdb0, i, gart_ptb_gpu_pa, flags);
> + drm_dev_exit(idx);
> }
>
> /**
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 0126ece898da..daa16d2f89da 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -800,7 +800,7 @@ static int amdgpu_vm_clear_bo(struct amdgpu_device *adev,
> struct amdgpu_bo *bo = &vmbo->bo;
> unsigned entries, ats_entries;
> uint64_t addr;
> - int r;
> + int r, idx;
>
> /* Figure out our place in the hierarchy */
> if (ancestor->parent) {
> @@ -845,9 +845,12 @@ static int amdgpu_vm_clear_bo(struct amdgpu_device *adev,
> return r;
> }
>
> + if (!drm_dev_enter(&adev->ddev, &idx))
> + return -ENODEV;
> +
> r = vm->update_funcs->map_table(vmbo);
> if (r)
> - return r;
> + goto exit;
>
> memset(¶ms, 0, sizeof(params));
> params.adev = adev;
> @@ -856,7 +859,7 @@ static int amdgpu_vm_clear_bo(struct amdgpu_device *adev,
>
> r = vm->update_funcs->prepare(¶ms, NULL, AMDGPU_SYNC_EXPLICIT);
> if (r)
> - return r;
> + goto exit;
>
> addr = 0;
> if (ats_entries) {
> @@ -872,7 +875,7 @@ static int amdgpu_vm_clear_bo(struct amdgpu_device *adev,
> r = vm->update_funcs->update(¶ms, vmbo, addr, 0, ats_entries,
> value, flags);
> if (r)
> - return r;
> + goto exit;
>
> addr += ats_entries * 8;
> }
> @@ -895,10 +898,13 @@ static int amdgpu_vm_clear_bo(struct amdgpu_device *adev,
> r = vm->update_funcs->update(¶ms, vmbo, addr, 0, entries,
> value, flags);
> if (r)
> - return r;
> + goto exit;
> }
>
> - return vm->update_funcs->commit(¶ms, NULL);
> + r = vm->update_funcs->commit(¶ms, NULL);
> +exit:
> + drm_dev_exit(idx);
> + return r;
> }
>
> /**
> @@ -1384,11 +1390,14 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
> struct amdgpu_vm *vm, bool immediate)
> {
> struct amdgpu_vm_update_params params;
> - int r;
> + int r, idx;
>
> if (list_empty(&vm->relocated))
> return 0;
>
> + if (!drm_dev_enter(&adev->ddev, &idx))
> + return -ENODEV;
> +
> memset(¶ms, 0, sizeof(params));
> params.adev = adev;
> params.vm = vm;
> @@ -1396,7 +1405,7 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
>
> r = vm->update_funcs->prepare(¶ms, NULL, AMDGPU_SYNC_EXPLICIT);
> if (r)
> - return r;
> + goto exit;
>
> while (!list_empty(&vm->relocated)) {
> struct amdgpu_vm_bo_base *entry;
> @@ -1414,10 +1423,13 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
> r = vm->update_funcs->commit(¶ms, &vm->last_update);
> if (r)
> goto error;
> + drm_dev_exit(idx);
> return 0;
>
> error:
> amdgpu_vm_invalidate_pds(adev, vm);
> +exit:
> + drm_dev_exit(idx);
> return r;
> }
>
> --
> 2.25.1
>
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