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=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 48759C388F7 for ; Wed, 28 Oct 2020 22:27:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFEB020704 for ; Wed, 28 Oct 2020 22:27:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="X+xQ59/V" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733288AbgJ1W1a (ORCPT ); Wed, 28 Oct 2020 18:27:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:58088 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733255AbgJ1W1X (ORCPT ); Wed, 28 Oct 2020 18:27:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603924043; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=0h+flQgRyOo5zRJQkxKmDTKn+RKN2hYzp8ToCDWH/6Y=; b=X+xQ59/VtGJREj+ErStGrVXvAHLp6ykzIJyGjQmY2E84Sf5cFQRgno884HsVRReq1qBhoU u4UDmPdciVVx/RmnkRRY3GDsm2AqDAjVaj02jBZ+3ygEqiiADO+LrCpFjSBcwTyzJwnSoy LUeuJeb74jAt7sMvjKA3bH+Sdc6ZBOo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-529-W-rgf9SBPE6VNEzhAMjuQA-1; Wed, 28 Oct 2020 11:24:39 -0400 X-MC-Unique: W-rgf9SBPE6VNEzhAMjuQA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 93EF4108E1A6; Wed, 28 Oct 2020 15:24:38 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-70.rdu2.redhat.com [10.10.120.70]) by smtp.corp.redhat.com (Postfix) with ESMTP id AC16D5D9EF; Wed, 28 Oct 2020 15:24:37 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20201028142041.GZ20115@casper.infradead.org> References: <20201028142041.GZ20115@casper.infradead.org> <160389418807.300137.8222864749005731859.stgit@warthog.procyon.org.uk> <160389422491.300137.18176057671220409936.stgit@warthog.procyon.org.uk> To: Matthew Wilcox Cc: dhowells@redhat.com, linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 05/11] afs: Fix to take ref on page when PG_private is set MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <442539.1603898676.1@warthog.procyon.org.uk> Date: Wed, 28 Oct 2020 15:24:36 +0000 Message-ID: <442540.1603898676@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Matthew Wilcox wrote: > There's an efficiency question here that I can't answer ... how often do > you call afs_write_begin() on a page which already has PagePrivate set? That's a question only userspace can answer - but think shell scripts that do lots of small appends. David