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=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A07B0C433DF for ; Mon, 17 Aug 2020 11:00:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 768EA2067C for ; Mon, 17 Aug 2020 11:00:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nYtFxTDl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728387AbgHQLAG (ORCPT ); Mon, 17 Aug 2020 07:00:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728363AbgHQK7j (ORCPT ); Mon, 17 Aug 2020 06:59:39 -0400 Received: from mail-il1-x141.google.com (mail-il1-x141.google.com [IPv6:2607:f8b0:4864:20::141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 383E5C061342 for ; Mon, 17 Aug 2020 03:59:39 -0700 (PDT) Received: by mail-il1-x141.google.com with SMTP id 77so14073729ilc.5 for ; Mon, 17 Aug 2020 03:59:39 -0700 (PDT) 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=mRFKMn469rvJhbWPmwRlBDaHdkmhCPJ0BZ8j32mtJZ8=; b=nYtFxTDlguMrPy84wfm448P60GlInQ7IF6vj7mfgT+/kHB8EL9ZE3BIajxXy6O+CnG oiOVOML039xpDFQXS9P0FqmUspW3JExsgLjasj8rZSfKaY/zPKzRjcaexFXPwd6oj9/9 UgahkMybxjI7uz6FwlLOLZQd/Gxjm8txa1PhkFigBFT07tviMtLt5GupPjt8ubs8hSmI gXFWrIAXriIiUl9Ork9197tmvAOpzwIyfxMEzk/l+PdqgSJlp+CeCYEspyUQkczU14fh RTLo4a5KTluMp+5wiqvuF1T2afYhnr+fGdLqg6ykzSNMWmR+jJ89cwiOlt42bs2429Id ZKXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=mRFKMn469rvJhbWPmwRlBDaHdkmhCPJ0BZ8j32mtJZ8=; b=S8BgF7bec/02xoAm0CLdqRJCsHJ+GcEZ0hKg+k7iGJ+Bg0qaawK+gkbWJFmP67Mqn5 tkrEojjWGIAk2UPIGhtovFMI8xmgV+VlFbOUPjvdGe/OirgpWLSC0ISF+fNtdTi2CmQR AEgWX0tOWw8br6Lj2PrY/6SxxpA4xuyxnuwnKlw2BuZc3S1L6/gLc3gnZqj0/RPS4cVt RRlsWL4OlJmEXFUtFrxebgutYbgagU9/pFBD6quys+2rWTFJumLeBSsaIcxStHNJUSwy A7ULm3ZO+0w4RCGbMs9AOYjd9QfR432ZbJzBmw17it2UcaaNkcnE7wMruH53JY1LrQLo j2Yg== X-Gm-Message-State: AOAM532edQDpNkkEaLOPk8E4N28WsEmAeDo5VF4t9tUpSTVJyncmNZFt WONcOYwWFCBE3zBEpbWhtap71ORXKcdzQbKZTgdM4EDIeg8= X-Google-Smtp-Source: ABdhPJz/QfASkB2AoUF3H9HAnFJU6XXHvJ/U1MYXBfXZTb/tYWN+NSY2WoyFrL+ntJxqIizgsyeEfbprGLbH/1tYPAM= X-Received: by 2002:a92:c7ae:: with SMTP id f14mr13948607ilk.39.1597661978616; Mon, 17 Aug 2020 03:59:38 -0700 (PDT) MIME-Version: 1.0 References: <1597395824-3325-1-git-send-email-zhaoyang.huang@unisoc.com> <20200814131034.f71a91c6827904e12a629e04@linux-foundation.org> <20200814211459.65f6db0211872e30684a630a@linux-foundation.org> In-Reply-To: <20200814211459.65f6db0211872e30684a630a@linux-foundation.org> From: Zhaoyang Huang Date: Mon, 17 Aug 2020 18:59:27 +0800 Message-ID: Subject: Re: [PATCH] mm : sync ra->ra_pages with bdi->ra_pages To: Andrew Morton Cc: Roman Gushchin , Zhaoyang Huang , "open list:MEMORY MANAGEMENT" , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 15, 2020 at 12:15 PM Andrew Morton wrote: > > On Fri, 14 Aug 2020 13:10:34 -0700 Andrew Morton wrote: > > > On Fri, 14 Aug 2020 17:03:44 +0800 Zhaoyang Huang wrote: > > > > > Some system(like android) will turbo read during startup via expanding the > > > readahead window and then set it back to normal(128kb as usual). However, some > > > files in the system process context will keep to be opened since it is opened > > > up and has no chance to sync with the updated value as it is almost impossible > > > to change the files attached to the inode(processes are unaware of these things) > > > > How about making VM_READAHEAD_PAGES a variable? > > Or make it settable in Kconfig? I don't think so. The scenario I gave before is a dynamic process, can't be solved via menuconfig thing.