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[142.162.113.129]) by smtp.gmail.com with ESMTPSA id h20sm318081qtr.81.2021.09.01.11.09.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Sep 2021 11:09:14 -0700 (PDT) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1mLUfi-0088XO-9Q; Wed, 01 Sep 2021 15:09:14 -0300 Date: Wed, 1 Sep 2021 15:09:14 -0300 From: Jason Gunthorpe To: David Hildenbrand Cc: Qi Zheng , akpm@linux-foundation.org, tglx@linutronix.de, hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, kirill.shutemov@linux.intel.com, mika.penttila@nextfour.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, songmuchun@bytedance.com Subject: Re: [PATCH v2 6/9] mm: free user PTE page table pages Message-ID: <20210901180914.GS1200268@ziepe.ca> References: <20210901135314.GA1859446@nvidia.com> <0c9766c9-6e8b-5445-83dc-9f2b71a76b4f@redhat.com> <20210901153247.GJ1721383@nvidia.com> <7789261d-6a64-c47b-be6c-c9be680e5d33@redhat.com> <20210901161613.GN1721383@nvidia.com> <20210901171039.GO1721383@nvidia.com> <20210901175547.GP1721383@nvidia.com> <52ba8125-0382-3270-a958-ed113ae1db2a@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52ba8125-0382-3270-a958-ed113ae1db2a@redhat.com> Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=ziepe.ca header.s=google header.b=Ox9bs87n; dmarc=none; spf=pass (imf23.hostedemail.com: domain of jgg@ziepe.ca designates 209.85.160.182 as permitted sender) smtp.mailfrom=jgg@ziepe.ca X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 4B3F69000387 X-Stat-Signature: c1mxgqo98dsmodf1tpt5n7b33ypqmei1 X-HE-Tag: 1630519756-200942 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Sep 01, 2021 at 07:58:47PM +0200, David Hildenbrand wrote: > You'll most likely have to touch each and every place either way, for > example when suddenly returning "null" instead of a pte. It's just a matter > of making this easier to review and the changes as minimal and as clear as > possible. I imagine the leading series to add the simplified API would include the null return already - the THP race avoidance requires it anyhow. So you end up with a simpler self contained series that is a stand alone improvement followed by a much smaller series here that doesn't got back and re-touch the first series's changes. Jason