From: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com> To: Daniel Vetter <daniel@ffwll.ch> Cc: daniel.vetter@ffwll.ch, michel@daenzer.net, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, ckoenig.leichtzumerken@gmail.com Subject: Re: [PATCH v2 2/8] drm/ttm: Remap all page faults to per process dummy page. Date: Tue, 10 Nov 2020 12:41:49 -0500 [thread overview] Message-ID: <0dccaf3d-8696-4368-26d2-8127a1314a34@amd.com> (raw) In-Reply-To: <20200622094103.GA20149@phenom.ffwll.local> On 6/22/20 5:41 AM, Daniel Vetter wrote: > On Sun, Jun 21, 2020 at 02:03:02AM -0400, Andrey Grodzovsky wrote: >> On device removal reroute all CPU mappings to dummy page per drm_file >> instance or imported GEM object. >> >> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com> >> --- >> drivers/gpu/drm/ttm/ttm_bo_vm.c | 65 ++++++++++++++++++++++++++++++++++++----- >> 1 file changed, 57 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c >> index 389128b..2f8bf5e 100644 >> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c >> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c >> @@ -35,6 +35,8 @@ >> #include <drm/ttm/ttm_bo_driver.h> >> #include <drm/ttm/ttm_placement.h> >> #include <drm/drm_vma_manager.h> >> +#include <drm/drm_drv.h> >> +#include <drm/drm_file.h> >> #include <linux/mm.h> >> #include <linux/pfn_t.h> >> #include <linux/rbtree.h> >> @@ -328,19 +330,66 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) > Hm I think diff and code flow look a bit bad now. What about renaming the > current function to __ttm_bo_vm_fault and then having something like the > below: > > ttm_bo_vm_fault(args) { > > if (drm_dev_enter()) { > __ttm_bo_vm_fault(args); > drm_dev_exit(); > } else { > drm_gem_insert_dummy_pfn(); > } > } > > I think drm_gem_insert_dummy_pfn(); should be portable across drivers, so > another nice point to try to unifiy drivers as much as possible. > -Daniel > >> pgprot_t prot; >> struct ttm_buffer_object *bo = vma->vm_private_data; >> vm_fault_t ret; >> + int idx; >> + struct drm_device *ddev = bo->base.dev; >> >> - ret = ttm_bo_vm_reserve(bo, vmf); >> - if (ret) >> - return ret; >> + if (drm_dev_enter(ddev, &idx)) { >> + ret = ttm_bo_vm_reserve(bo, vmf); >> + if (ret) >> + goto exit; >> + >> + prot = vma->vm_page_prot; >> >> - prot = vma->vm_page_prot; >> - ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT); >> - if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) >> + ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT); >> + if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) >> + goto exit; >> + >> + dma_resv_unlock(bo->base.resv); >> + >> +exit: >> + drm_dev_exit(idx); >> return ret; >> + } else { >> >> - dma_resv_unlock(bo->base.resv); >> + struct drm_file *file = NULL; >> + struct page *dummy_page = NULL; >> + int handle; >> >> - return ret; >> + /* We are faulting on imported BO from dma_buf */ >> + if (bo->base.dma_buf && bo->base.import_attach) { >> + dummy_page = bo->base.dummy_page; >> + /* We are faulting on non imported BO, find drm_file owning the BO*/ > Uh, we can't fish that out of the vma->vm_file pointer somehow? Or is that > one all wrong? Doing this kind of list walk looks pretty horrible. > > If the vma doesn't have the right pointer I guess next option is that we > store the drm_file page in gem_bo->dummy_page, and replace it on first > export. But that's going to be tricky to track ... For this one I hope to make all of this obsolete if Christian's suggestion from path 1/8 about mapping global RO dummy page for read and COW on write will be possible to implement (testing that indeed no memory usage explodes) Andrey > >> + } else { >> + struct drm_gem_object *gobj; >> + >> + mutex_lock(&ddev->filelist_mutex); >> + list_for_each_entry(file, &ddev->filelist, lhead) { >> + spin_lock(&file->table_lock); >> + idr_for_each_entry(&file->object_idr, gobj, handle) { >> + if (gobj == &bo->base) { >> + dummy_page = file->dummy_page; >> + break; >> + } >> + } >> + spin_unlock(&file->table_lock); >> + } >> + mutex_unlock(&ddev->filelist_mutex); >> + } >> + >> + if (dummy_page) { >> + /* >> + * Let do_fault complete the PTE install e.t.c using vmf->page >> + * >> + * TODO - should i call free_page somewhere ? > Nah, instead don't call get_page. The page will be around as long as > there's a reference for the drm_file or gem_bo, which is longer than any > mmap. Otherwise yes this would like really badly. > >> + */ >> + get_page(dummy_page); >> + vmf->page = dummy_page; >> + return 0; >> + } else { >> + return VM_FAULT_SIGSEGV; > Hm that would be a kernel bug, wouldn't it? WARN_ON() required here imo. > -Daniel > >> + } >> + } >> } >> EXPORT_SYMBOL(ttm_bo_vm_fault); >> >> -- >> 2.7.4 >> _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
WARNING: multiple messages have this Message-ID (diff)
From: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com> To: Daniel Vetter <daniel@ffwll.ch> Cc: daniel.vetter@ffwll.ch, michel@daenzer.net, dri-devel@lists.freedesktop.org, ppaalanen@gmail.com, amd-gfx@lists.freedesktop.org, ckoenig.leichtzumerken@gmail.com, alexdeucher@gmail.com Subject: Re: [PATCH v2 2/8] drm/ttm: Remap all page faults to per process dummy page. Date: Tue, 10 Nov 2020 12:41:49 -0500 [thread overview] Message-ID: <0dccaf3d-8696-4368-26d2-8127a1314a34@amd.com> (raw) In-Reply-To: <20200622094103.GA20149@phenom.ffwll.local> On 6/22/20 5:41 AM, Daniel Vetter wrote: > On Sun, Jun 21, 2020 at 02:03:02AM -0400, Andrey Grodzovsky wrote: >> On device removal reroute all CPU mappings to dummy page per drm_file >> instance or imported GEM object. >> >> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com> >> --- >> drivers/gpu/drm/ttm/ttm_bo_vm.c | 65 ++++++++++++++++++++++++++++++++++++----- >> 1 file changed, 57 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c >> index 389128b..2f8bf5e 100644 >> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c >> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c >> @@ -35,6 +35,8 @@ >> #include <drm/ttm/ttm_bo_driver.h> >> #include <drm/ttm/ttm_placement.h> >> #include <drm/drm_vma_manager.h> >> +#include <drm/drm_drv.h> >> +#include <drm/drm_file.h> >> #include <linux/mm.h> >> #include <linux/pfn_t.h> >> #include <linux/rbtree.h> >> @@ -328,19 +330,66 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) > Hm I think diff and code flow look a bit bad now. What about renaming the > current function to __ttm_bo_vm_fault and then having something like the > below: > > ttm_bo_vm_fault(args) { > > if (drm_dev_enter()) { > __ttm_bo_vm_fault(args); > drm_dev_exit(); > } else { > drm_gem_insert_dummy_pfn(); > } > } > > I think drm_gem_insert_dummy_pfn(); should be portable across drivers, so > another nice point to try to unifiy drivers as much as possible. > -Daniel > >> pgprot_t prot; >> struct ttm_buffer_object *bo = vma->vm_private_data; >> vm_fault_t ret; >> + int idx; >> + struct drm_device *ddev = bo->base.dev; >> >> - ret = ttm_bo_vm_reserve(bo, vmf); >> - if (ret) >> - return ret; >> + if (drm_dev_enter(ddev, &idx)) { >> + ret = ttm_bo_vm_reserve(bo, vmf); >> + if (ret) >> + goto exit; >> + >> + prot = vma->vm_page_prot; >> >> - prot = vma->vm_page_prot; >> - ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT); >> - if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) >> + ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT); >> + if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) >> + goto exit; >> + >> + dma_resv_unlock(bo->base.resv); >> + >> +exit: >> + drm_dev_exit(idx); >> return ret; >> + } else { >> >> - dma_resv_unlock(bo->base.resv); >> + struct drm_file *file = NULL; >> + struct page *dummy_page = NULL; >> + int handle; >> >> - return ret; >> + /* We are faulting on imported BO from dma_buf */ >> + if (bo->base.dma_buf && bo->base.import_attach) { >> + dummy_page = bo->base.dummy_page; >> + /* We are faulting on non imported BO, find drm_file owning the BO*/ > Uh, we can't fish that out of the vma->vm_file pointer somehow? Or is that > one all wrong? Doing this kind of list walk looks pretty horrible. > > If the vma doesn't have the right pointer I guess next option is that we > store the drm_file page in gem_bo->dummy_page, and replace it on first > export. But that's going to be tricky to track ... For this one I hope to make all of this obsolete if Christian's suggestion from path 1/8 about mapping global RO dummy page for read and COW on write will be possible to implement (testing that indeed no memory usage explodes) Andrey > >> + } else { >> + struct drm_gem_object *gobj; >> + >> + mutex_lock(&ddev->filelist_mutex); >> + list_for_each_entry(file, &ddev->filelist, lhead) { >> + spin_lock(&file->table_lock); >> + idr_for_each_entry(&file->object_idr, gobj, handle) { >> + if (gobj == &bo->base) { >> + dummy_page = file->dummy_page; >> + break; >> + } >> + } >> + spin_unlock(&file->table_lock); >> + } >> + mutex_unlock(&ddev->filelist_mutex); >> + } >> + >> + if (dummy_page) { >> + /* >> + * Let do_fault complete the PTE install e.t.c using vmf->page >> + * >> + * TODO - should i call free_page somewhere ? > Nah, instead don't call get_page. The page will be around as long as > there's a reference for the drm_file or gem_bo, which is longer than any > mmap. Otherwise yes this would like really badly. > >> + */ >> + get_page(dummy_page); >> + vmf->page = dummy_page; >> + return 0; >> + } else { >> + return VM_FAULT_SIGSEGV; > Hm that would be a kernel bug, wouldn't it? WARN_ON() required here imo. > -Daniel > >> + } >> + } >> } >> EXPORT_SYMBOL(ttm_bo_vm_fault); >> >> -- >> 2.7.4 >> _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
next prev parent reply other threads:[~2020-11-10 17:41 UTC|newest] Thread overview: 194+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-21 6:03 [PATCH v2 0/8] RFC Support hot device unplug in amdgpu Andrey Grodzovsky 2020-06-21 6:03 ` Andrey Grodzovsky 2020-06-21 6:03 ` [PATCH v2 1/8] drm: Add dummy page per device or GEM object Andrey Grodzovsky 2020-06-21 6:03 ` Andrey Grodzovsky 2020-06-22 9:35 ` Daniel Vetter 2020-06-22 9:35 ` Daniel Vetter 2020-06-22 14:21 ` Pekka Paalanen 2020-06-22 14:21 ` Pekka Paalanen 2020-06-22 14:24 ` Daniel Vetter 2020-06-22 14:24 ` Daniel Vetter 2020-06-22 14:28 ` Pekka Paalanen 2020-06-22 14:28 ` Pekka Paalanen 2020-11-09 20:34 ` Andrey Grodzovsky 2020-11-09 20:34 ` Andrey Grodzovsky 2020-11-15 6:39 ` Andrey Grodzovsky 2020-11-15 6:39 ` Andrey Grodzovsky 2020-06-22 13:18 ` Christian König 2020-06-22 13:18 ` Christian König 2020-06-22 14:23 ` Daniel Vetter 2020-06-22 14:23 ` Daniel Vetter 2020-06-22 14:32 ` Andrey Grodzovsky 2020-06-22 14:32 ` Andrey Grodzovsky 2020-06-22 17:45 ` Christian König 2020-06-22 17:45 ` Christian König 2020-06-22 17:50 ` Daniel Vetter 2020-06-22 17:50 ` Daniel Vetter 2020-11-09 20:53 ` Andrey Grodzovsky 2020-11-09 20:53 ` Andrey Grodzovsky 2020-11-13 20:52 ` Andrey Grodzovsky 2020-11-13 20:52 ` Andrey Grodzovsky 2020-11-14 8:41 ` Christian König 2020-11-14 8:41 ` Christian König 2020-11-14 9:51 ` Daniel Vetter 2020-11-14 9:51 ` Daniel Vetter 2020-11-14 9:57 ` Daniel Vetter 2020-11-14 9:57 ` Daniel Vetter 2020-11-16 9:42 ` Michel Dänzer 2020-11-16 9:42 ` Michel Dänzer 2020-11-15 6:34 ` Andrey Grodzovsky 2020-11-15 6:34 ` Andrey Grodzovsky 2020-11-16 9:48 ` Christian König 2020-11-16 9:48 ` Christian König 2020-11-16 19:00 ` Andrey Grodzovsky 2020-11-16 19:00 ` Andrey Grodzovsky 2020-11-16 20:36 ` Christian König 2020-11-16 20:36 ` Christian König 2020-11-16 20:42 ` Andrey Grodzovsky 2020-11-16 20:42 ` Andrey Grodzovsky 2020-11-19 10:01 ` Christian König 2020-11-19 10:01 ` Christian König 2020-06-21 6:03 ` [PATCH v2 2/8] drm/ttm: Remap all page faults to per process dummy page Andrey Grodzovsky 2020-06-21 6:03 ` Andrey Grodzovsky 2020-06-22 9:41 ` Daniel Vetter 2020-06-22 9:41 ` Daniel Vetter 2020-06-24 3:31 ` Andrey Grodzovsky 2020-06-24 3:31 ` Andrey Grodzovsky 2020-06-24 7:19 ` Daniel Vetter 2020-06-24 7:19 ` Daniel Vetter 2020-11-10 17:41 ` Andrey Grodzovsky [this message] 2020-11-10 17:41 ` Andrey Grodzovsky 2020-06-22 19:30 ` Christian König 2020-06-22 19:30 ` Christian König 2020-06-21 6:03 ` [PATCH v2 3/8] drm/ttm: Add unampping of the entire device address space Andrey Grodzovsky 2020-06-21 6:03 ` Andrey Grodzovsky 2020-06-22 9:45 ` Daniel Vetter 2020-06-22 9:45 ` Daniel Vetter 2020-06-23 5:00 ` Andrey Grodzovsky 2020-06-23 5:00 ` Andrey Grodzovsky 2020-06-23 10:25 ` Daniel Vetter 2020-06-23 10:25 ` Daniel Vetter 2020-06-23 12:55 ` Christian König 2020-06-23 12:55 ` Christian König 2020-06-22 19:37 ` Christian König 2020-06-22 19:37 ` Christian König 2020-06-22 19:47 ` Alex Deucher 2020-06-22 19:47 ` Alex Deucher 2020-06-21 6:03 ` [PATCH v2 4/8] drm/amdgpu: Split amdgpu_device_fini into early and late Andrey Grodzovsky 2020-06-21 6:03 ` Andrey Grodzovsky 2020-06-22 9:48 ` Daniel Vetter 2020-06-22 9:48 ` Daniel Vetter 2020-11-12 4:19 ` Andrey Grodzovsky 2020-11-12 4:19 ` Andrey Grodzovsky 2020-11-12 9:29 ` Daniel Vetter 2020-11-12 9:29 ` Daniel Vetter 2020-06-21 6:03 ` [PATCH v2 5/8] drm/amdgpu: Refactor sysfs removal Andrey Grodzovsky 2020-06-21 6:03 ` Andrey Grodzovsky 2020-06-22 9:51 ` Daniel Vetter 2020-06-22 9:51 ` Daniel Vetter 2020-06-22 11:21 ` Greg KH 2020-06-22 11:21 ` Greg KH 2020-06-22 16:07 ` Andrey Grodzovsky 2020-06-22 16:07 ` Andrey Grodzovsky 2020-06-22 16:45 ` Greg KH 2020-06-22 16:45 ` Greg KH 2020-06-23 4:51 ` Andrey Grodzovsky 2020-06-23 4:51 ` Andrey Grodzovsky 2020-06-23 6:05 ` Greg KH 2020-06-23 6:05 ` Greg KH 2020-06-24 3:04 ` Andrey Grodzovsky 2020-06-24 3:04 ` Andrey Grodzovsky 2020-06-24 6:11 ` Greg KH 2020-06-24 6:11 ` Greg KH 2020-06-25 1:52 ` Andrey Grodzovsky 2020-06-25 1:52 ` Andrey Grodzovsky 2020-11-10 17:54 ` Andrey Grodzovsky 2020-11-10 17:54 ` Andrey Grodzovsky 2020-11-10 17:59 ` Greg KH 2020-11-10 17:59 ` Greg KH 2020-11-11 15:13 ` Andrey Grodzovsky 2020-11-11 15:13 ` Andrey Grodzovsky 2020-11-11 15:34 ` Greg KH 2020-11-11 15:34 ` Greg KH 2020-11-11 15:45 ` Andrey Grodzovsky 2020-11-11 15:45 ` Andrey Grodzovsky 2020-11-11 16:06 ` Greg KH 2020-11-11 16:06 ` Greg KH 2020-11-11 16:34 ` Andrey Grodzovsky 2020-11-11 16:34 ` Andrey Grodzovsky 2020-12-02 15:48 ` Andrey Grodzovsky 2020-12-02 15:48 ` Andrey Grodzovsky 2020-12-02 17:34 ` Greg KH 2020-12-02 17:34 ` Greg KH 2020-12-02 18:02 ` Andrey Grodzovsky 2020-12-02 18:02 ` Andrey Grodzovsky 2020-12-02 18:20 ` Greg KH 2020-12-02 18:20 ` Greg KH 2020-12-02 18:40 ` Andrey Grodzovsky 2020-12-02 18:40 ` Andrey Grodzovsky 2020-06-22 13:19 ` Christian König 2020-06-22 13:19 ` Christian König 2020-06-21 6:03 ` [PATCH v2 6/8] drm/amdgpu: Unmap entire device address space on device remove Andrey Grodzovsky 2020-06-21 6:03 ` Andrey Grodzovsky 2020-06-22 9:56 ` Daniel Vetter 2020-06-22 9:56 ` Daniel Vetter 2020-06-22 19:38 ` Christian König 2020-06-22 19:38 ` Christian König 2020-06-22 19:48 ` Alex Deucher 2020-06-22 19:48 ` Alex Deucher 2020-06-23 10:22 ` Daniel Vetter 2020-06-23 10:22 ` Daniel Vetter 2020-06-23 13:16 ` Christian König 2020-06-23 13:16 ` Christian König 2020-06-24 3:12 ` Andrey Grodzovsky 2020-06-24 3:12 ` Andrey Grodzovsky 2020-06-21 6:03 ` [PATCH v2 7/8] drm/amdgpu: Fix sdma code crash post device unplug Andrey Grodzovsky 2020-06-21 6:03 ` Andrey Grodzovsky 2020-06-22 9:55 ` Daniel Vetter 2020-06-22 9:55 ` Daniel Vetter 2020-06-22 19:40 ` Christian König 2020-06-22 19:40 ` Christian König 2020-06-23 5:11 ` Andrey Grodzovsky 2020-06-23 5:11 ` Andrey Grodzovsky 2020-06-23 7:14 ` Christian König 2020-06-23 7:14 ` Christian König 2020-06-21 6:03 ` [PATCH v2 8/8] drm/amdgpu: Prevent any job recoveries after device is unplugged Andrey Grodzovsky 2020-06-21 6:03 ` Andrey Grodzovsky 2020-06-22 9:53 ` Daniel Vetter 2020-06-22 9:53 ` Daniel Vetter 2020-11-17 18:38 ` Andrey Grodzovsky 2020-11-17 18:38 ` Andrey Grodzovsky 2020-11-17 18:52 ` Daniel Vetter 2020-11-17 18:52 ` Daniel Vetter 2020-11-17 19:18 ` Andrey Grodzovsky 2020-11-17 19:18 ` Andrey Grodzovsky 2020-11-17 19:49 ` Daniel Vetter 2020-11-17 19:49 ` Daniel Vetter 2020-11-17 20:07 ` Andrey Grodzovsky 2020-11-17 20:07 ` Andrey Grodzovsky 2020-11-18 7:39 ` Daniel Vetter 2020-11-18 7:39 ` Daniel Vetter 2020-11-18 12:01 ` Christian König 2020-11-18 12:01 ` Christian König 2020-11-18 15:43 ` Luben Tuikov 2020-11-18 15:43 ` Luben Tuikov 2020-11-18 16:20 ` Andrey Grodzovsky 2020-11-18 16:20 ` Andrey Grodzovsky 2020-11-19 7:55 ` Christian König 2020-11-19 7:55 ` Christian König 2020-11-19 15:02 ` Andrey Grodzovsky 2020-11-19 15:02 ` Andrey Grodzovsky 2020-11-19 15:29 ` Daniel Vetter 2020-11-19 15:29 ` Daniel Vetter 2020-11-19 21:24 ` Andrey Grodzovsky 2020-11-19 21:24 ` Andrey Grodzovsky 2020-11-18 0:46 ` Luben Tuikov 2020-11-18 0:46 ` Luben Tuikov 2020-06-22 9:46 ` [PATCH v2 0/8] RFC Support hot device unplug in amdgpu Daniel Vetter 2020-06-22 9:46 ` Daniel Vetter 2020-06-23 5:14 ` Andrey Grodzovsky 2020-06-23 5:14 ` Andrey Grodzovsky 2020-06-23 9:04 ` Michel Dänzer 2020-06-23 9:04 ` Michel Dänzer 2020-06-24 3:21 ` Andrey Grodzovsky 2020-06-24 3:21 ` Andrey Grodzovsky
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