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 AC28A438486; Wed, 15 Jul 2026 12:41:50 +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=1784119311; cv=none; b=gMN8DMvFjfulzbkGK5awRwlT1FOTJZNBXSejD102h5S0blFlnDMIrrAKwOpsnLQbcyaORe/RcRr2dRJyCisAmaRjwKvHBJieye6fzVRg9HAvZvw2rQQS0NRSFFb5NS9/VbGOTNgptuoVpz/EMBH0HCf4M+MXMCLgwSuXJTjf9LI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784119311; c=relaxed/simple; bh=QuEDZJFL+qyNlITZqW/G2y7tQy4cY9BI1R+tuUMYa5o=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=kPMzE8lelqeCDnj7JZXqfnzMq7DpJPSpgf9lurrRU+x4QPhDP5CPWEU06m5Wt0H2/WIIgtmd/5IKER8vx4S9h7uTEYgdvzmnKaInK5OXfyFC2gPhzeHm0wisFAYJHmn9xNqe3D0YLF+gIeUpZFWq40+qqwGJwTLCltGqZUhaN5A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eElLlbTE; 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="eElLlbTE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0010E1F000E9; Wed, 15 Jul 2026 12:41:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784119310; bh=LFYijXd/eRRjsT6uSgIi2DnkFRuxM3htkW3xD91av44=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=eElLlbTEYVW/Jv0j5NkpBDZmaXElwE/+fDmcnfu1UvCt7uGcMFYiLv1KaEZA3HCXk 4/R42D0LV7X6nQ8UJ+lhfxI3Mt8el0GSnM3W4P7jD11TilEUq9ug7431XSZPN+fzKN eXn1hBbLgcDg4YgdjjjBS7zMgJEtBvqu5fhWNjMEP+F82umJBb+ZEs3x2ZSiECEO49 hZQsDTx85qRVroPgev2eTkvGta2k9aySNX5ysXR+OIpRpCqSoDdceLtpthwpSXOKTW U4BIJCdmMz6pLo4FeuFM4ZgqIBSRbkxbKrmjOtcPaCIdT1KHnVXu7CyH8SUIEYB9OX 467FF/XXPbOLQ== Message-ID: <4300f09b-8f93-4605-b072-7c09a82cb16e@kernel.org> Date: Wed, 15 Jul 2026 14:41:43 +0200 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 0/4] mm/hmm: Clarify notifier retry state and scope HMM timeouts To: Stanislav Kinsburskii , 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, ljs@kernel.org, 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 Cc: 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 References: <178406760622.1106335.2379450382728057793.stgit@skinsburskii> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 8bit 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? -- Cheers, David