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(p200300cbc7079e00fec07e9615cb0742.dip0.t-ipconnect.de. [2003:cb:c707:9e00:fec0:7e96:15cb:742]) by smtp.gmail.com with ESMTPSA id k14-20020a5d428e000000b00225232154d7sm9124954wrq.110.2022.09.01.10.44.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 01 Sep 2022 10:44:03 -0700 (PDT) Message-ID: Date: Thu, 1 Sep 2022 19:44:02 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.12.0 Subject: Re: [PATCH v1] mm/gup: adjust stale comment for RCU GUP-fast To: Peter Xu Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A . Shutemov" , Sasha Levin , "Aneesh Kumar K . V" , Vlastimil Babka , Jerome Marchand , Andrea Arcangeli , Hugh Dickins , Jason Gunthorpe , John Hubbard , Yang Shi References: <20220901072119.37588-1-david@redhat.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662054248; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=FQOn0UueP4f1CSvnyezbvyIBmYegvrdiesOa5q4EoyU=; b=In+wav9m3g4lguk+78GFhpT9VEBjazbZyAgGWicZSFbqf/OF1GRJhEQ/ShA+T8/DLI0z8E Tg83QszgckNXD8BDnCOfW1VSWeptxFiAAnEbQoUC4MaOQquehamtwQmeDvNPDLWCeUhS+m SGiZ5muDt3/JJqP23MgE/II/TQ8raJY= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=dbK9uVRu; spf=pass (imf16.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662054248; a=rsa-sha256; cv=none; b=u3aFHBtTwPq/QQ/YavkWexa2h7GJiRY79nCmRuLB5/qLoeP0KDZg23kt2OhtNyMVHU3jee FKwDX9nVbmgOr9n5RTjHNP4awP7Zu9aS9dft8vn+E0AjNJPS58SnLLRC/Du4uvoQz9Vglm HzdMd+BZZ1OGFn1Hf3ZVyC86bavj8Qw= Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=dbK9uVRu; spf=pass (imf16.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-Rspam-User: X-Stat-Signature: 1qkgsc9dhu6u95i5b3mk85oijzym5m8p X-Rspamd-Queue-Id: A309D18004A X-Rspamd-Server: rspam05 X-HE-Tag: 1662054248-569793 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: >>> It can be dropped later if you want to rework the thp collapse side and >>> finally remove IPI dependency on fast-gup, but so far it seems to me it's >>> still needed. Or just drop this patch until that rework happens? >> >> The doc as is is obviously stale, why drop this patch? >> >> We should see a fix for the THP collapse issue very soon I guess. Most >> probably this patch will go upstream after that fix. > > No objection to have this patch alone as the removal statement is only > about "thp split". But IMHO this patch alone didn't really help a great > lot, especially if you plan to have more to come that is very relevant to > this, so it'll be clearer to put them together. Your call. I can hold off the resend until the the fix is in place. Then I can add to the description that we are not aware of remaining IPI dependencies, and one undocumented case was broken and got fixed without the need for IPIs. Thanks! -- Thanks, David / dhildenb