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=-4.1 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, URIBL_BLOCKED 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 05497C433DF for ; Fri, 14 Aug 2020 02:20:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B2B2E20771 for ; Fri, 14 Aug 2020 02:20:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XndHlTSw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B2B2E20771 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 34A966B000C; Thu, 13 Aug 2020 22:20:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2FC436B000D; Thu, 13 Aug 2020 22:20:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1EB046B000E; Thu, 13 Aug 2020 22:20:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0250.hostedemail.com [216.40.44.250]) by kanga.kvack.org (Postfix) with ESMTP id 07ADA6B000C for ; Thu, 13 Aug 2020 22:20:24 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id BA1A3180AD807 for ; Fri, 14 Aug 2020 02:20:23 +0000 (UTC) X-FDA: 77147569926.23.point31_35029a426ff9 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id 9182B37606 for ; Fri, 14 Aug 2020 02:20:23 +0000 (UTC) X-HE-Tag: point31_35029a426ff9 X-Filterd-Recvd-Size: 3973 Received: from mail-il1-f195.google.com (mail-il1-f195.google.com [209.85.166.195]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Fri, 14 Aug 2020 02:20:23 +0000 (UTC) Received: by mail-il1-f195.google.com with SMTP id p18so3426532ilm.7 for ; Thu, 13 Aug 2020 19:20:22 -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=CkLV7ie2J+t0XB/OSS4F8NU6METCllJZJy8f/Ga/ZDk=; b=XndHlTSw0ANSubbW8BKu8mD78kMKS5Qyf/8xvUa+nMg1KbyYxoSvlncSkfVjuSXxTE 5oHqXT5V9gn0jyP+ku7ucfdiIorKlvcvcd4OXxdmNvvzUuKIsR9ymd59jm0prhSd4p4I RIZminFBDB7ASFwA8EUTSQKE22N23umlFPzQXDIsMAqT3CdnhNfXeKJyHkX2eP4EY3bZ lohLxsW3twdgUlkhrvwIYPbCyhs83B2cc1Yuldc/G6sekQRvpDlsvBS39yrnAtq5fO0m 8x7elm3WasH3RUpbtEJMfVrm93XaiI4IWlquk9NZb50PHWEgo1puRB5eTN1ZbNI6Ca+p l4Zw== 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=CkLV7ie2J+t0XB/OSS4F8NU6METCllJZJy8f/Ga/ZDk=; b=B+h7y7hc9nWKgE472ipjjb72eqnAoVrmdHxYH72j+9u2lc0KQqUJPAeXWakMpCnGBF CNvYImCPDVJk+r2DOzagpZwqycVKs4v92FTXc2RI19yOuhJZjBQnqQlB35m7VzgnqUID rD2Vkm9MaSUeQtxvZ1C38MC7t3TrFM3wXlWARH24eeCpAR2ra2w4NTjZJ+lqwSLrOLzC qJtOKV+thA1HQ0EiKxv3qyE24yBo07oDMoJ5dj9vtJxM8Akm5SFcLIRVWhbzEKAmNWXs Unbnuly+F4dbKeZo8WPLn1WtoYmDH6ZCT1LMnKb7Mfrj79NlRX6OC6g7x/7BK4OrHqax 4NBQ== X-Gm-Message-State: AOAM532ElT1Y6lutv7guZfnI/9uy4NZvXk+UOHkTj/xV+JnPVq7J7oZ6 gtjExCBvsoPlabBPQkiojOhm2HvkWhV5TXI0aIQ= X-Google-Smtp-Source: ABdhPJxS1ITSn4yt2q6cxPjycgYcLi8b2Fdp+jxRcd1zrznyP+kc2U7fWY+HD+9qxKlI+W8jvhG/CAhDhkS8E3lLnCM= X-Received: by 2002:a92:6904:: with SMTP id e4mr684998ilc.83.1597371622512; Thu, 13 Aug 2020 19:20:22 -0700 (PDT) MIME-Version: 1.0 References: <1597368611-7631-1-git-send-email-zhaoyang.huang@unisoc.com> <20200814014355.GS17456@casper.infradead.org> <20200814020700.GT17456@casper.infradead.org> In-Reply-To: <20200814020700.GT17456@casper.infradead.org> From: Zhaoyang Huang Date: Fri, 14 Aug 2020 10:20:11 +0800 Message-ID: Subject: Re: [PATCH] mm : update ra->ra_pages if it's NOT equal to bdi->ra_pages To: Matthew Wilcox Cc: Roman Gushchin , Andrew Morton , Zhaoyang Huang , "open list:MEMORY MANAGEMENT" , LKML Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 9182B37606 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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, Aug 14, 2020 at 10:07 AM Matthew Wilcox wrote: > > On Fri, Aug 14, 2020 at 02:43:55AM +0100, Matthew Wilcox wrote: > > On Fri, Aug 14, 2020 at 09:30:11AM +0800, Zhaoyang Huang wrote: > > > file->f_ra->ra_pages will remain the initialized value since it opend, which may > > > be NOT equal to bdi->ra_pages as the latter one is updated somehow(etc, > > > echo xxx > /sys/block/dm/queue/read_ahead_kb).So sync ra->ra_pages to the > > > updated value when sync read. > > > > It still ignores the work done by shrink_readahead_size_eio() > > and fadvise(POSIX_FADV_SEQUENTIAL). > > ... by the way, if you're trying to update one particular file's readahead > state, you can just call fadvise(POSIX_FADV_NORMAL) on it. > > If you want to update every open file's ra_pages by writing to sysfs, > then just no. We don't do that. No, What I want to fix is the file within one process's context keeps using the initialized value when it is opened and not sync with new value when bdi->ra_pages changes. > > You haven't said what problem you're facing, so I really can't be more > helpful.