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[209.85.220.65]) by mx.google.com with SMTPS id x6sor28237132otq.80.2019.07.27.10.25.15 for (Google Transport Security); Sat, 27 Jul 2019 10:25:15 -0700 (PDT) Received-SPF: pass (google.com: domain of lpf.vector@gmail.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=t5kSA4pk; spf=pass (google.com: domain of lpf.vector@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=lpf.vector@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=GnqU0JRhrXBsiEdVfrpxRYhB+jhyBUboMzh3dp1tPvc=; b=t5kSA4pkhco77TShAAaMPIl1DAEIo8hLSMUCCmpXXj9Z8l3AEbxPPtTPHlV27fOVCe +QJQV64yQyneiJ4QqJPMJz3diUQwGaL4/cpogzyHUCg0Sw1VfPAdf7kqhvMlLEZveam+ 7DsthIZxv3KZwo3AhW5msgxhNpyk+tXDIzqCHi2JE2v400wzBomRYOUxc+EhGPpTrFLM hPMyRRpACoOCg/4w0nvsFNxcp9eX0nTVgXYoCqc0bj25txMqcBi0X59HZZ4tV5F26AZY 1NDtFdARA+3mlYVIDc5P1pBt/GoLferKZo6H5ZRD+8DssJMi5hiMQP7iV4cWC6Z0GW7e 2JAw== X-Google-Smtp-Source: APXvYqzgh59g+ACIfiw2qGNQLkF6F1GlClI1XRgmH1D5Yjm7nb8sSCqgU3QzmV3GAkGYA4zf8O3vnAkHF2nB2QLUeKs= X-Received: by 2002:a9d:460d:: with SMTP id y13mr53509367ote.368.1564248314917; Sat, 27 Jul 2019 10:25:14 -0700 (PDT) MIME-Version: 1.0 References: <20190725184253.21160-1-lpf.vector@gmail.com> <1564080768.11067.22.camel@lca.pw> <20190726071219.GC6142@dhcp22.suse.cz> In-Reply-To: <20190726071219.GC6142@dhcp22.suse.cz> From: Pengfei Li Date: Sun, 28 Jul 2019 01:25:02 +0800 Message-ID: Subject: Re: [PATCH 00/10] make "order" unsigned int To: Michal Hocko Cc: Qian Cai , Andrew Morton , Mel Gorman , vbabka@suse.cz, aryabinin@virtuozzo.com, osalvador@suse.de, rostedt@goodmis.org, mingo@redhat.com, pavel.tatashin@microsoft.com, rppt@linux.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org 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: On Fri, Jul 26, 2019 at 3:12 PM Michal Hocko wrote: > Thank you for your comments. > On Fri 26-07-19 07:48:36, Pengfei Li wrote: > [...] > > For the benefit, "order" may be negative, which is confusing and weird. > > order = -1 has a special meaning. > Yes. But I mean -1 can be replaced by any number greater than MAX_ORDER - 1 and there is no reason to be negative. > > There is no good reason not to do this since it can be avoided. > > "This is good because we can do it" doesn't really sound like a > convincing argument to me. I would understand if this reduced a > generated code, made an overall code readability much better or > something along those lines. Also we only use MAX_ORDER range of values > so I could argue that a smaller data type (e.g. short) should be > sufficient for this data type. > I resend an email to interpret the meaning of my commit, and I would be very grateful if you post some comments on this. > Please note that _any_ change, alebit seemingly small, can introduce a > subtle bug. Also each patch requires a man power to review so you have > to understand that "just because we can" is not a strong motivation for > people to spend their time on such a patch. Sincerely thank you, I will keep these in mind. > -- > Michal Hocko > SUSE Labs -- Pengfei