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CAT:NONE; SFS:(4636009)(36840700001)(46966006)(336012)(86362001)(426003)(6916009)(316002)(82310400003)(7696005)(508600001)(36860700001)(6666004)(8676002)(4326008)(356005)(36756003)(83380400001)(16526019)(44832011)(186003)(26005)(70586007)(5660300002)(2616005)(8936002)(1076003)(70206006)(2906002)(47076005)(81166007)(36900700001); DIR:OUT; SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 01 Nov 2021 22:04:49.3250 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 01eeec9b-8d5a-4405-b9e3-08d99d839fac X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d; Ip=[165.204.84.17]; Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT027.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR12MB4269 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alex Sierra Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" [Why]: During hmm_range_fault validation calls on VRAM migrations, there could be cases where some pages within the range could be marked as Read Only (COW) triggering a migration back to RAM. In this case, the migration to RAM will try to grab mutexes that have been held already before the hmm_range_fault call. Causing a recursive lock. [How]: Creating a task reference new member under prange struct. And setting this with "current" reference, right before the hmm_range_fault is called. This member is checked against "current" reference at svm_migrate_to_ram callback function. If equal, the migration will be ignored. Signed-off-by: Alex Sierra --- drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 4 ++++ drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 1 + drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 3 +++ 3 files changed, 8 insertions(+) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c index bff40e8bca67..eb19f44ec86d 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c @@ -936,6 +936,10 @@ static vm_fault_t svm_migrate_to_ram(struct vm_fault *vmf) pr_debug("failed find process at fault address 0x%lx\n", addr); return VM_FAULT_SIGBUS; } + if (READ_ONCE(p->svms.faulting_task) == current) { + pr_debug("skipping ram migration\n"); + return 0; + } addr >>= PAGE_SHIFT; pr_debug("CPU page fault svms 0x%p address 0x%lx\n", &p->svms, addr); diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h index f88666bdf57c..7b41a58b1ade 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h @@ -858,6 +858,7 @@ struct svm_range_list { atomic_t evicted_ranges; struct delayed_work restore_work; DECLARE_BITMAP(bitmap_supported, MAX_GPU_INSTANCE); + struct task_struct *faulting_task; }; /* Process data */ diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 939c863315ba..e9eeee2e571c 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -1492,9 +1492,11 @@ static int svm_range_validate_and_map(struct mm_struct *mm, next = min(vma->vm_end, end); npages = (next - addr) >> PAGE_SHIFT; + WRITE_ONCE(p->svms.faulting_task, current); r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL, addr, npages, &hmm_range, readonly, true, owner); + WRITE_ONCE(p->svms.faulting_task, NULL); if (r) { pr_debug("failed %d to get svm range pages\n", r); goto unreserve_out; @@ -2745,6 +2747,7 @@ int svm_range_list_init(struct kfd_process *p) INIT_WORK(&svms->deferred_list_work, svm_range_deferred_list_work); INIT_LIST_HEAD(&svms->deferred_range_list); spin_lock_init(&svms->deferred_list_lock); + svms->faulting_task = NULL; for (i = 0; i < p->n_pdds; i++) if (KFD_IS_SVM_API_SUPPORTED(p->pdds[i]->dev)) -- 2.32.0