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 69ECA3ACF02; Wed, 15 Jul 2026 16:03:18 +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=1784131399; cv=none; b=BURRQS8jyX7peWOnogYrLIc4mnE1NXGM4J48j2iPq1UJGl/wqlkLBeoMpY44siDCROP9r0VpZvE75cRgCND8qPh69Sl69yrpoT7RVXej5XzANShOtk45j7NuY/Dk9DUXpjWBhRZ4ii0J+OitzMDUBEIsSvOkdF77qpCdgtDhalY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784131399; c=relaxed/simple; bh=j66ycXNqmfL9ElgeVy3WnEOOmbqq6eqLlP83Cj5txIc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=D62+2ZNsRC5qYNLToHzxCNqg9X5i8BdvidEnqZ6Iwcb+8yRdtH2JwiEjqu9nDL+y708/H0JDTv3vNjMCNZbuSswHmOWBQNOVv8lmZUIz2lRFzm/TVuUGObkB4261tkS/z05qRqOepRrDdmWBkIcjBu9Mi7C9Eu+mUzVM6XcD2Y0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BTe0PVEt; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BTe0PVEt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45DD31F00AC4; Wed, 15 Jul 2026 16:03:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784131398; bh=f4C6n0w9mDrtHRCnStTGRTvpeLhmwUbbHGkqcxBvTik=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=BTe0PVEtIUgNNd0HJimWRQQVEEPMbL5+bzLWuypuzi9NIZDNIO6kUqirtSxlAWLFk PrBLqf5Yq1l3QU6VH4iviptT0e9bRWpUM/uEXAasgR77pKC9z+vQd3N/ZT12gq+TOA iSjdO6i4rRi3jSv2zcy+p4iHl9QURtzFzqcQgPTQEhJK2/xGqbUIZZT2Vi6+Rct4P3 d+GhP1nj6V3srM5djsFI26cexSh0CwKsIKZqFVpU6Sr6h376esJkNnOtKiwg2jmpGj k+k3ZxxMJZcOYT4zJ80nQ91avqazBAS8yWXPX8UPGPMQCt3fqQNPTCHC8TVxaX0t6I khlJo9zamFdrw== Date: Wed, 15 Jul 2026 17:02:59 +0100 From: "Lorenzo Stoakes (ARM)" To: Stanislav Kinsburskii Cc: "David Hildenbrand (Arm)" , airlied@gmail.com, akhilesh@ee.iitb.ac.in, akpm@linux-foundation.org, corbet@lwn.net, dakr@kernel.org, jgg@ziepe.ca, kees@kernel.org, leon@kernel.org, liam@infradead.org, lizhi.hou@amd.com, lyude@redhat.com, maarten.lankhorst@linux.intel.com, mamin506@gmail.com, mhocko@suse.com, mripard@kernel.org, nouveau@lists.freedesktop.org, ogabbay@kernel.org, oleg@redhat.com, rppt@kernel.org, shuah@kernel.org, simona@ffwll.ch, skhan@linuxfoundation.org, surenb@google.com, tzimmermann@suse.de, vbabka@kernel.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-rdma@vger.kernel.org Subject: Re: [PATCH v2 0/4] mm/hmm: Clarify notifier retry state and scope HMM timeouts Message-ID: References: <178406760622.1106335.2379450382728057793.stgit@skinsburskii> <4300f09b-8f93-4605-b072-7c09a82cb16e@kernel.org> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: To avoid confusion: obviously please don't merge this series Andrew. On Wed, Jul 15, 2026 at 07:42:48AM -0700, Stanislav Kinsburskii wrote: > On Wed, Jul 15, 2026 at 02:41:43PM +0200, David Hildenbrand (Arm) wrote: > > On 7/15/26 00:21, Stanislav Kinsburskii wrote: > > > This small fixup series applies on top of: > > > > > > [PATCH v8 0/8] mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings > > > > > > The first patch updates the HMM documentation example to make the > > > mmu_interval_read_retry() state explicit: callers should use the notifier and > > > notifier_seq stored in the same hmm_range that was passed to > > > hmm_range_fault_unlocked_timeout(). > > > > > > The remaining patches adjust nouveau, amdxdna, and drm_gpusvm users so the > > > timeout passed to hmm_range_fault_unlocked_timeout() is treated as a relative > > > HMM retry budget. These callers no longer keep an absolute deadline around > > > their outer driver retry loops or pass a computed remaining time into HMM. > > > > > > This keeps the timeout scoped to HMM's internal mmu-notifier retry handling. If > > > HMM succeeds and the driver later observes an invalidation through > > > mmu_interval_read_retry(), the driver retries the operation with a fresh HMM > > > retry budget. > > > > > > Changes in v2: > > > - Kept the nouveau outer absolute timeout around the > > > mmu_interval_read_retry() loop. hmm_range_fault_unlocked_timeout() only > > > bounds HMM’s internal retries, while nouveau faults are handled from a GPU > > > fault worker, so userspace fatal signals cannot break an endless stream of > > > invalidations there. > > > - Updated nouveau to use time_after_eq() before calling HMM, so the remaining > > > timeout passed to hmm_range_fault_unlocked_timeout() is always positive and > > > never 0, which would mean retry indefinitely. > > > - Updated the nouveau fixup commit message to explain the worker-thread > > > timeout issue and the time_after_eq() boundary behavior. > > > - Fixed the amdxdna fixup commit message. It now describes > > > aie2_populate_range() correctly instead of carrying stale nouveau prose, > > > and notes that command submission still keeps its broader timeout while HMM > > > gets a fresh relative retry budget. > > > > > > > > > --- > > > > > > Stanislav Kinsburskii (4): > > > fixup! mm/hmm: add hmm_range_fault_unlocked_timeout() for mmap lock-drop support > > > fixup! drm/nouveau: use hmm_range_fault_unlocked_timeout() for SVM faults > > > fixup! accel/amdxdna: use hmm_range_fault_unlocked_timeout() for range population > > > fixup! drm/gpusvm: use hmm_range_fault_unlocked_timeout() for range faults > > > > Why a fixup series instead of properly resending the full thing? > > > > The goal was to get a Sashiko review, and v8 has already been applied to > both `mm-new` and `linux-next`. Please don't do this, this is completely impossible to track for review :) mm review is currently very difficult based on volumes, it'll become impossible to manage if people sound fragments of series. Please just resend the whole thing at this point. > > You can find more details here: > > https://sashiko.dev/#/message/alaWmUEeIBeSkmO0%40skinsburskii > > Thanks, Stanislav > > > -- > > Cheers, > > > > David Thanks, Lorenzo