From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAC00C433EF for ; Mon, 9 Sep 2019 12:14:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DDBF2067B for ; Mon, 9 Sep 2019 12:14:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cT6yqph1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404764AbfIIMOl (ORCPT ); Mon, 9 Sep 2019 08:14:41 -0400 Received: from mail-lj1-f195.google.com ([209.85.208.195]:46502 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387486AbfIIMOl (ORCPT ); Mon, 9 Sep 2019 08:14:41 -0400 Received: by mail-lj1-f195.google.com with SMTP id e17so12434369ljf.13; Mon, 09 Sep 2019 05:14:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=pFxxPSGzQ82HZys0kjMWLu4nLMt5F1OM+dYrK3t5KUE=; b=cT6yqph1WHqVo4BHlHeHqAFIMjTp3Acp1uVHcbqgwoGOlIqlovKxe503zA/8WoErXn BsWhEeubNs5SBKrX8zemTpTQpyKf8aURKe0eusDLzbJEENZEzm6PLiW7MfyRmJb9iEGy Leso6x2MVJCDmsDCySr6Fk9QaENJKtSycGQWa6kfr8C39QyA5ldbGwlHBTOR1tDsdWd0 P+rXYyvw3PbqWdOBOoxAr1hANjCQCVJnAL9q9WHrrS84jvSXz6kkIRt4UvcNpYSV9ZbK aCTAcUs1drW3WqJy+mZdDwDKVRS/0p0q7xHOxWc3NbKica2BqUH7trc0iekrUEknEvsu 32eQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=pFxxPSGzQ82HZys0kjMWLu4nLMt5F1OM+dYrK3t5KUE=; b=ebvpi8iS2U9OPqTuy1658fqExJz46P7FRqMjOHKiTjEpvOxJbEsbSBFhSWTNUOEeTa 1w/ioCNKiv66eCPb8VOh2rE/mkf4zhCBBrBCaGmQ1mlz4sH6LvHQjF/uoeXH9IfVAAhc 9lPu/VAR3Gnctm39x55b/ZxjSuVgNq9iVzmn3ZuX77x4iwnO3/gSRhdz1Ikhl7ZNikvd qekbf1HR606CB7mwBUg0XV0xD4tP8jDW9OKSm5r59iAbRAhDeBgefCK/Wlsi5l698mxG sWfM5tsq8KFT4mUhH/BX7xgHv9/MvTr8hc+mqmrsMMaO/eX3TGe69acZwCj/gCfP0QJ5 4fhA== X-Gm-Message-State: APjAAAUaI656Bdci6pHZJdLM59Wacb3vrCmg+3Reycl6gJWm3jrq6Stg M1N8hhB0Ux5QNG11zm5eY88= X-Google-Smtp-Source: APXvYqwVLHKAjKXgmeV9NavO0mi2f/oJuinAaLJ4bnqdtte2ZZ4wLTD/k1MwfPEpTbw4bERFkaDxrg== X-Received: by 2002:a2e:9dd5:: with SMTP id x21mr15547930ljj.182.1568031278902; Mon, 09 Sep 2019 05:14:38 -0700 (PDT) Received: from uranus.localdomain ([5.18.103.226]) by smtp.gmail.com with ESMTPSA id k28sm3212244lfj.33.2019.09.09.05.14.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Sep 2019 05:14:37 -0700 (PDT) Received: by uranus.localdomain (Postfix, from userid 1000) id D81D7460667; Mon, 9 Sep 2019 15:14:36 +0300 (MSK) Date: Mon, 9 Sep 2019 15:14:36 +0300 From: Cyrill Gorcunov To: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Dmitry Safonov , open list , Adrian Reber , Alexander Viro , Andrei Vagin , Andy Lutomirski , Ingo Molnar , Oleg Nesterov , Pavel Emelyanov , Thomas Gleixner , Linux Containers , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 4/9] select: Micro-optimise __estimate_accuracy() Message-ID: <20190909121436.GC1508@uranus> References: <20190909102340.8592-1-dima@arista.com> <20190909102340.8592-5-dima@arista.com> <20190909111812.GB1508@uranus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 09, 2019 at 12:50:27PM +0100, Dmitry Safonov wrote: > Hi Cyrill, > > On Mon, 9 Sep 2019 at 12:18, Cyrill Gorcunov wrote: > > Compiler precompute constants so it doesn't do division here. > > But I didn't read the series yet so I might be missing > > something obvious. > > Heh, like a division is in ktime_divns()? Ah, you meant the ktime_divns you've dropped out. I thought you were talking about the constant value we've had here before your patch. Seems I didn't got the changelog right. Anyway need to take more precise look on the series. Hopefully soon.