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=1.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, FSL_HELO_FAKE,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 4B9F8C43441 for ; Tue, 27 Nov 2018 02:08:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BC3F20664 for ; Tue, 27 Nov 2018 02:08:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="APF4VPda" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0BC3F20664 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728023AbeK0NEN (ORCPT ); Tue, 27 Nov 2018 08:04:13 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:46133 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727542AbeK0NEN (ORCPT ); Tue, 27 Nov 2018 08:04:13 -0500 Received: by mail-pl1-f194.google.com with SMTP id t13so14790188ply.13 for ; Mon, 26 Nov 2018 18:08:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=BlnmJVYVEGZKLMQ25R2Xgla7R6htgSgHhtIQgm4J3Fo=; b=APF4VPdaH7OltL6Z+YvnAMPArkq4fpl3+fG6NluJSP2gLPCkuCJjwLs5t1TmEvwHTd 7Ollz3z+VWcvt96SuquzClGJCZ0PoMuVTO7vvveAy3ABzHpG+BQWeK4ww+lJZr3XBd/9 CF82Rgb88fpuqk1NWU6cmqE/o1vM1ifTLkUuDAHBtEAbIXcSZp0SKY08o20/dH7F22wO bzk8SG2fenBqmJfDmJSVCgX7Szg1DQZpuVZ+8aXCgIdxR7GkTN3wgvM950B5p3ACJHl9 wFutP8h9O0nsk+MDpFyeYxinY2zzCtZmg/GcUTQzbPWTo2HGrLPQTn28PUMqh3Ke7plH pE4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=BlnmJVYVEGZKLMQ25R2Xgla7R6htgSgHhtIQgm4J3Fo=; b=RNgvgTZPoeqy7ruZtymj7qDQGn2FbE0TeWQp2WLJmAd5VoSOyevZdXKBwD3odhUuk/ Xzgl3s6/9wjb2gMfI/BgPBPzYE8J0gsLtWnH+lrZB/jractECAtEy8AKLo1SBIUL9vHy Xdm2xF5qr4NrbVV1xCjnz8Rn27KyWz5ADwOG60mHK0CzUm6LCuUqIPUwsTLpmwOMpbxT T02DkqLd4ZCnFT/uVFYv67Q4gQEijX2BwvJw6VKfkAXgK4+sRC6xcExb44iJa6NHQBLD aWFIhdyHO9Qv8TcrJJl2ZKb3UmAPpA8wLQaiLrE7zQymWTy2SfQJ60bYvjuV/rg7kCAU yhIg== X-Gm-Message-State: AA+aEWZ5zbgnsq7+CPJ4wSZKIsuEk460B06pc411ADRONAc5QDW3zawx w2jFtCtDtK2G3+n8+7j1GaSfSgh6NQg= X-Google-Smtp-Source: AFSGD/XpaLegHDduOCRGFr7+ULiiNS2tpNqgHFVR9qkzeBHee31LSWdj8V3/KPgKBzRwCZT5sqSzuA== X-Received: by 2002:a17:902:e101:: with SMTP id cc1-v6mr30909414plb.165.1543284479554; Mon, 26 Nov 2018 18:07:59 -0800 (PST) Received: from google.com ([2401:fa00:d:0:98f1:8b3d:1f37:3e8]) by smtp.gmail.com with ESMTPSA id 6sm4837512pfv.30.2018.11.26.18.07.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 26 Nov 2018 18:07:58 -0800 (PST) Date: Tue, 27 Nov 2018 11:07:54 +0900 From: Minchan Kim To: Andrew Morton Cc: LKML , Sergey Senozhatsky Subject: Re: [PATCH v2 6/7] zram: add bd_stat statistics Message-ID: <20181127020754.GB237537@google.com> References: <20181126082813.81977-1-minchan@kernel.org> <20181126082813.81977-7-minchan@kernel.org> <20181126125833.e95a21088ae60ccc6fd55022@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181126125833.e95a21088ae60ccc6fd55022@linux-foundation.org> User-Agent: Mutt/1.10.1+60 (6df12dc1) (2018-08-07) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 26, 2018 at 12:58:33PM -0800, Andrew Morton wrote: > On Mon, 26 Nov 2018 17:28:12 +0900 Minchan Kim wrote: > > > +File /sys/block/zram/bd_stat > > + > > +The stat file represents device's backing device statistics. It consists of > > +a single line of text and contains the following stats separated by whitespace: > > + bd_count size of data written in backing device. > > + Unit: pages > > + bd_reads the number of reads from backing device > > + Unit: pages > > + bd_writes the number of writes to backing device > > + Unit: pages > > Using `pages' is a bad choice. And I assume this means that > writeback_limit is in pages as well, which is worse. > > Page sizes are not constant! We want userspace which was developed on > 4k pagesize to work the same on 64k pagesize. > > Arguably, we could require that well-written userspace remember to use > getpagesize(). However we have traditionally tried to avoid that by > performing the pagesize normalization within the kernel. zram works based on page so I used that term but I agree it's rather vague. If there is no objection, I will use (Unit: 4K) instead of (Unit: pages).