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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,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 DC92AC35240 for ; Thu, 23 Jan 2020 23:25:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A820F207FF for ; Thu, 23 Jan 2020 23:25:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579821926; bh=wEeDKzLrdYAJ/fBHeU2h2gwQKPjX4vFELabN5Y7XPIM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=WTCD8lCLL+RIdABYNSNEa+Whs+1AHm6WHcJZf12ND4mHLNH6LC6CeD9XwelUIQ4za 8MS5FpkI9tBn7A1RiNeYxr4KkHip55SAYvFDFvzn71t6xqBsOfJYB2AthnFL8ZdxlZ u+wfYtJ4i2y4OWJHRxFtKOZVBTe9jYDBbjO47df8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730052AbgAWXZZ (ORCPT ); Thu, 23 Jan 2020 18:25:25 -0500 Received: from mail-pj1-f66.google.com ([209.85.216.66]:39645 "EHLO mail-pj1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729085AbgAWXZZ (ORCPT ); Thu, 23 Jan 2020 18:25:25 -0500 Received: by mail-pj1-f66.google.com with SMTP id e11so192591pjt.4 for ; Thu, 23 Jan 2020 15:25:24 -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=Edd2Wi9CD7RrglB/fQLlFZdfwFT64T8pCBM8AIxpxRQ=; b=Rejig7sl+v5cTLadH95ckrE/rFk85vPl4HWBUDko2L/5EgxUF57mdzjOxn0IHrV5T7 7/G0B4lZkCpwbCp079KN5/1C8qItxdlKvyh+c8C6aFyU+YQ0KTwYp7SjALNUivYlTBan 886eaYPN8cN+q7DOovP28CAcVu+M7VUZXW0jqyNdj12A8WJmuARiwM/5aehPLeHVaYpt dCy4VcL5tN24Yx4nvlrvHm/k2dH5yjf5nuBLKmJUUMiprCoa9Fr1RJGPdhbYk1FVHHwC y3c102SFPLNukper2GMznVAYO0NK3tPHlXv4adEJrzQeNb+dQ6OL5Bp0mvs4Q98RJmaz L/BQ== 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=Edd2Wi9CD7RrglB/fQLlFZdfwFT64T8pCBM8AIxpxRQ=; b=OTFPcO0T8l0JQ6HJ5orzF2gAYTytm/axMdEB6bJxBIOtu+z7fBwJxvL4bUbDtogLX1 v0/yikH89rtYZEQaPOgsFzaSh5Dw9I2D3Du1zvvFllky6ZIol8ubxrguZ+hpLFCGhCSp k8xPZvU7PnmRpi88ZCaDQgpkk7j515s+ZPWNeUOq/k2p7FuaFyGA14FpyWXO2858AVwm jsentCzhn50kVBH0Ptb3VHz7dJ9/m6isOfJu+SrXbLHSrxWeZYH2M2XfTZKHd1IJpeEZ rZ1/jQIs/23tSnIA2QdrQcYcSYvEXIlgPGjAbisysJ/QsNhr5eWULi6iKjj0EQZyV5Ac bDgQ== X-Gm-Message-State: APjAAAV7zQkiWD37Ft4F1TR4wM0GfC8+KutVZqUHxsYF6EA2esxC46J/ 3ojttnACqvK33/Fe6iMW730= X-Google-Smtp-Source: APXvYqzzMftVoUgjQhJK1vpYFxX8dzEdoEPnGYUIRR0hhgmGNOftifj/eEYiWjAZwRWQiuBSTOsCLQ== X-Received: by 2002:a17:902:d688:: with SMTP id v8mr585163ply.238.1579821924459; Thu, 23 Jan 2020 15:25:24 -0800 (PST) Received: from google.com ([2620:15c:211:1:3e01:2939:5992:52da]) by smtp.gmail.com with ESMTPSA id a16sm4007742pgb.5.2020.01.23.15.25.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jan 2020 15:25:23 -0800 (PST) Date: Thu, 23 Jan 2020 15:25:21 -0800 From: Minchan Kim To: Yue Hu Cc: ngupta@vflare.org, sergey.senozhatsky.work@gmail.com, linux-kernel@vger.kernel.org, huyue2@yulong.com Subject: Re: [PATCH] zram: do not set ZRAM_IDLE bit for idlepage writeback in writeback_store() Message-ID: <20200123232521.GA175683@google.com> References: <20200121113557.11608-1-zbestahu@gmail.com> <20200123022305.GF249784@google.com> <20200123103936.000044ba.zbestahu@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200123103936.000044ba.zbestahu@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 23, 2020 at 10:39:36AM +0800, Yue Hu wrote: > On Wed, 22 Jan 2020 18:23:05 -0800 > Minchan Kim wrote: > > > On Tue, Jan 21, 2020 at 07:35:57PM +0800, Yue Hu wrote: > > > From: Yue Hu > > > > > > Currently, we will call zram_set_flag() to set ZRAM_IDLE bit even for > > > idlepage writeback. That is pointless. Let's set it only for hugepage mode. > > > > Could you be more specific? What do you see the problem with that? > > If current writeback mode is idle, ZRAM_IDLE bit will be check firstly for this > slot. Then go to call zram_set_flag(, , ZRAM_IDLE) if it's marked as ZRAM_IDLE. > So, it's duplicated setting, am i right? As I wrote down in the description, it aims for the race with hugepage writeback. Without it, there is no way to detect the slot is reallocated and marked with huge again but it's new data so zram could free the page unintentionally.