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[209.85.208.170]) by smtp.gmail.com with ESMTPSA id s19sm950785lfb.224.2020.10.08.10.09.22 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 08 Oct 2020 10:09:23 -0700 (PDT) Received: by mail-lj1-f170.google.com with SMTP id h20so6550522lji.9 for ; Thu, 08 Oct 2020 10:09:22 -0700 (PDT) X-Received: by 2002:a2e:2202:: with SMTP id i2mr3411487lji.70.1602176962536; Thu, 08 Oct 2020 10:09:22 -0700 (PDT) MIME-Version: 1.0 References: <20201008092541.398079-1-aneesh.kumar@linux.ibm.com> In-Reply-To: <20201008092541.398079-1-aneesh.kumar@linux.ibm.com> From: Linus Torvalds Date: Thu, 8 Oct 2020 10:09:06 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] mm: Avoid using set_pte_at when updating a present pte To: "Aneesh Kumar K.V" , Leon Romanovsky Cc: linuxppc-dev , Michael Ellerman , Nick Piggin , Peter Xu , Jason Gunthorpe , John Hubbard , Linux-MM , Linux Kernel Mailing List , Andrew Morton , Jan Kara , Michal Hocko , Kirill Shutemov , Hugh Dickins Content-Type: text/plain; charset="UTF-8" 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: Ahh, and I should learn to read all my emails before replying to some of them.. On Thu, Oct 8, 2020 at 2:26 AM Aneesh Kumar K.V wrote: > > This avoids the below warning > [..] > WARNING: CPU: 0 PID: 30613 at arch/powerpc/mm/pgtable.c:185 set_pte_at+0x2a8/0x3a0 arch/powerpc/mm/pgtable.c:185 .. and I assume this is what triggered the other patch too. Yes, with the ppc warning, we need to do _something_ about this, and at that point I think the "something" is to just avoid the pte wrpritect trick. Linus