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[172.10.233.147]) by smtp.gmail.com with ESMTPSA id l134sm8666271oig.25.2020.12.27.22.44.01 (version=TLS1 cipher=ECDHE-ECDSA-AES128-SHA bits=128/128); Sun, 27 Dec 2020 22:44:02 -0800 (PST) Date: Sun, 27 Dec 2020 22:43:44 -0800 (PST) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Linus Torvalds cc: "Kirill A. Shutemov" , Hugh Dickins , Matthew Wilcox , "Kirill A. Shutemov" , Will Deacon , Linux Kernel Mailing List , Linux-MM , Linux ARM , Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , Vinayak Menon , Android Kernel Team Subject: Re: [PATCH 1/2] mm: Allow architectures to request 'old' entries when prefaulting In-Reply-To: Message-ID: References: <20201225113157.e7hmluffh56fszfc@box> <20201226204335.dikqkrkezqet6oqf@box> <20201226224016.dxjmordcfj75xgte@box> <20201227234853.5mjyxcybucts3kbq@box> User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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 Sun, 27 Dec 2020, Linus Torvalds wrote: > On Sun, Dec 27, 2020 at 3:48 PM Kirill A. Shutemov wrote: > > > > I did what Hugh proposed and it got clear to my eyes. It gets somewhat > > large, but take a look. > > Ok, it's not that much bigger, and the end result is certainly much > clearer wrt locking. > > So that last version of yours with the fix for the uninitialized 'ret' > variable looks good to me. > > Of course, I've said that before, and have been wrong. So ... And guess what... it's broken. I folded it into testing rc1: segfault on cc1, systemd "Journal file corrupted, rotating", seen on more than one machine. I've backed it out, rc1 itself seems fine, I'll leave rc1 under load overnight, then come back to the faultaround patch tomorrow; won't glance at it tonight, but maybe Kirill will guess what's wrong. Hugh