From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96A0F3BB66C for ; Wed, 15 Jul 2026 21:18:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784150314; cv=none; b=YWg813LLN/pc5pVOjfWbG/PVqDzDL13GTBQsLTFzP+VDEKryWc4lr2crWkVrOd9f7WpUr/5zA9ltf/ujmuQ+qF5ZWdOQ/T0fdoHcMMBnLn3Bm3/Jxqhhwl89aQglRDjJAOF15vYxWl3dN3tS1HE1EEEzapugxp4BzIQ2UXmq7IA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784150314; c=relaxed/simple; bh=YWCVPGBNTr0dzNdRJIDS0PAvTqhC0205YYTemW3RuRs=; h=Date:To:From:Subject:Message-Id; b=ZQ0uDVuZdLXOYCYkvvO0SV7c9uM28ISXQMi9sGefZACxDEWlM52XFrL9B9fEONkphOwzzCMa7UIQ1J2xtWxLPBibHV7Bf/JHZSqqHRHzEsBmhp/7t+K2qlgGbNGiXfI/FuuJxmt/D3aZbT4wJtLP6cclgh21VF8T5GerTMHRqLs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=DfH858fy; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="DfH858fy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 602AF1F000E9; Wed, 15 Jul 2026 21:18:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1784150312; bh=1ZddVCR/Ndx9Nv62C2Ns8czGucEynPXYQAKGqorhqDM=; h=Date:To:From:Subject; b=DfH858fybaTSssHzk4CHTxKHdWsqp83ZMnsU/jcV7FOW+PKqCqiDBBd6J1tBWpxmz BVRVjamP3O9JHR/qlKl0HsE6nAOAzjC0sI1cL1QRPTiL+bcphZCpQRALCEnNzCqJzA YAkmUVZw7PwvLE38CeLV/feYQ5LRg2T+cp9Ne0M8= Date: Wed, 15 Jul 2026 14:18:31 -0700 To: mm-commits@vger.kernel.org,skinsburskii@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + drm-gpusvm-use-hmm_range_fault_unlocked_timeout-for-range-faults.patch added to mm-unstable branch Message-Id: <20260715211832.602AF1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: drm/gpusvm: use hmm_range_fault_unlocked_timeout() for range faults has been added to the -mm mm-unstable branch. Its filename is drm-gpusvm-use-hmm_range_fault_unlocked_timeout-for-range-faults.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/drm-gpusvm-use-hmm_range_fault_unlocked_timeout-for-range-faults.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Stanislav Kinsburskii Subject: drm/gpusvm: use hmm_range_fault_unlocked_timeout() for range faults Date: Wed, 15 Jul 2026 11:16:52 -0700 Several GPU SVM paths take mmap_read_lock() only to call hmm_range_fault() and open-code mmu interval sequence setup before each HMM walk. They also retry -EBUSY until HMM_RANGE_DEFAULT_TIMEOUT expires. Use hmm_range_fault_unlocked_timeout() for those faults. The HMM helper now owns mmap_lock acquisition and refreshes range->notifier_seq for its internal retries, while GPU SVM keeps its existing driver-lock validation with mmu_interval_read_retry() after a successful fault. Pass HMM_RANGE_DEFAULT_TIMEOUT as the helper retry budget for each HMM fault attempt. This scopes the timeout to repeated HMM notifier retries while preserving the outer retry loops that restart when the interval is invalidated before GPU SVM updates or consumes the mapping state. Leave drm_gpusvm_check_pages() on hmm_range_fault() because that path is called with the mmap lock already held by its caller. Link: https://lore.kernel.org/178413941236.1155966.14485211391150425997.stgit@skinsburskii Signed-off-by: Stanislav Kinsburskii Reviewed-by: Jason Gunthorpe Cc: Danilo Krummrich Cc: Dave Airlie Cc: David Hildenbrand Cc: Dexuan Cui Cc: Haiyang Zhang Cc: Jonathan Corbet Cc: Kees Cook Cc: K. Y. Srinivasan Cc: Leon Romanovsky Cc: Liam R. Howlett Cc: Lizhi Hou Cc: Long Li Cc: Lorenzo Stoakes Cc: Lyude Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Michal Hocko Cc: Mike Rapoport Cc: Oded Gabbay Cc: Oleg Nesterov Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Thomas Zimemrmann Cc: Vlastimil Babka Cc: Wei Liu Signed-off-by: Andrew Morton --- drivers/gpu/drm/drm_gpusvm.c | 61 +++------------------------------ 1 file changed, 7 insertions(+), 54 deletions(-) --- a/drivers/gpu/drm/drm_gpusvm.c~drm-gpusvm-use-hmm_range_fault_unlocked_timeout-for-range-faults +++ a/drivers/gpu/drm/drm_gpusvm.c @@ -773,8 +773,7 @@ enum drm_gpusvm_scan_result drm_gpusvm_s .end = end, .dev_private_owner = dev_private_owner, }; - unsigned long timeout = - jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); + unsigned long timeout = msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); enum drm_gpusvm_scan_result state = DRM_GPUSVM_SCAN_UNPOPULATED, new_state; unsigned long *pfns; unsigned long npages = npages_in_range(start, end); @@ -788,22 +787,7 @@ enum drm_gpusvm_scan_result drm_gpusvm_s hmm_range.hmm_pfns = pfns; retry: - hmm_range.notifier_seq = mmu_interval_read_begin(notifier); - mmap_read_lock(range->gpusvm->mm); - - while (true) { - err = hmm_range_fault(&hmm_range); - if (err == -EBUSY) { - if (time_after(jiffies, timeout)) - break; - - hmm_range.notifier_seq = - mmu_interval_read_begin(notifier); - continue; - } - break; - } - mmap_read_unlock(range->gpusvm->mm); + err = hmm_range_fault_unlocked_timeout(&hmm_range, timeout); if (err) goto err_free; @@ -1406,8 +1390,7 @@ int drm_gpusvm_get_pages(struct drm_gpus .dev_private_owner = ctx->device_private_page_owner, }; void *zdd; - unsigned long timeout = - jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); + unsigned long timeout = msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); unsigned long i, j; unsigned long npages = npages_in_range(pages_start, pages_end); unsigned long num_dma_mapped; @@ -1422,9 +1405,6 @@ int drm_gpusvm_get_pages(struct drm_gpus struct dma_iova_state *state = &svm_pages->state; retry: - if (time_after(jiffies, timeout)) - return -EBUSY; - hmm_range.notifier_seq = mmu_interval_read_begin(notifier); if (drm_gpusvm_pages_valid_unlocked(gpusvm, svm_pages)) goto set_seqno; @@ -1439,21 +1419,7 @@ retry: } hmm_range.hmm_pfns = pfns; - while (true) { - mmap_read_lock(mm); - err = hmm_range_fault(&hmm_range); - mmap_read_unlock(mm); - - if (err == -EBUSY) { - if (time_after(jiffies, timeout)) - break; - - hmm_range.notifier_seq = - mmu_interval_read_begin(notifier); - continue; - } - break; - } + err = hmm_range_fault_unlocked_timeout(&hmm_range, timeout); mmput(mm); if (err) goto err_free; @@ -1720,8 +1686,7 @@ int drm_gpusvm_range_evict(struct drm_gp .end = drm_gpusvm_range_end(range), .dev_private_owner = NULL, }; - unsigned long timeout = - jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); + unsigned long timeout = msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); unsigned long *pfns; unsigned long npages = npages_in_range(drm_gpusvm_range_start(range), drm_gpusvm_range_end(range)); @@ -1736,24 +1701,12 @@ int drm_gpusvm_range_evict(struct drm_gp return -ENOMEM; hmm_range.hmm_pfns = pfns; - while (!time_after(jiffies, timeout)) { - hmm_range.notifier_seq = mmu_interval_read_begin(notifier); - if (time_after(jiffies, timeout)) { - err = -ETIME; - break; - } - - mmap_read_lock(mm); - err = hmm_range_fault(&hmm_range); - mmap_read_unlock(mm); - if (err != -EBUSY) - break; - } + err = hmm_range_fault_unlocked_timeout(&hmm_range, timeout); kvfree(pfns); mmput(mm); - return err; + return err == -EBUSY ? -ETIME : err; } EXPORT_SYMBOL_GPL(drm_gpusvm_range_evict); _ Patches currently in -mm which might be from skinsburskii@gmail.com are lib-test_hmm-use-device-devt-for-coherent-device-range-selection.patch mm-hmm-move-page-fault-handling-out-of-walk-callbacks.patch mm-hmm-add-hmm_range_fault_unlocked_timeout-for-mmap-lock-drop-support.patch selftests-mm-add-hmm-test-for-mmap-lock-dropping-faults.patch mshv-use-hmm_range_fault_unlocked_timeout-for-region-faults.patch drm-nouveau-use-hmm_range_fault_unlocked_timeout-for-svm-faults.patch rdma-umem-use-hmm_range_fault_unlocked_timeout-for-odp-faults.patch accel-amdxdna-use-hmm_range_fault_unlocked_timeout-for-range-population.patch drm-gpusvm-use-hmm_range_fault_unlocked_timeout-for-range-faults.patch