From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 36748 invoked by alias); 10 Nov 2016 08:26:43 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 36737 invoked by uid 89); 10 Nov 2016 08:26:42 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-4.8 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=State X-HELO: mx1.redhat.com Subject: Re: [libc/string] State of PAGE_COPY_FWD / PAGE_COPY_THRESHOLD To: Maxim Kuvyrkov , Adhemerval Zanella References: <193512EC-DC6C-4BDF-8138-1C1F54B30A12@linaro.org> Cc: libc-alpha@sourceware.org From: Florian Weimer Message-ID: <99998c8e-f9e5-cffd-1d4c-502954b751f2@redhat.com> Date: Thu, 10 Nov 2016 08:26:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <193512EC-DC6C-4BDF-8138-1C1F54B30A12@linaro.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2016-11/txt/msg00381.txt.bz2 On 11/10/2016 08:39 AM, Maxim Kuvyrkov wrote: > A quick investigation shows that there is no such syscall provided by the Linux kernel. Doesn't mean we can't ask for / implement one. Linux did exactly this when you read a large block from /dev/zero. It was removed because it did not provide any real benefit to applications. It just looked very good in certain benchmarks. Florian