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=-5.8 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 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 C4131C433B4 for ; Thu, 8 Apr 2021 15:25:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87680610FB for ; Thu, 8 Apr 2021 15:25:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232227AbhDHPZ6 (ORCPT ); Thu, 8 Apr 2021 11:25:58 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:54441 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231785AbhDHPZ6 (ORCPT ); Thu, 8 Apr 2021 11:25:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617895546; 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=CGwlC/hESn7y7qGIlb10fpokHrJdwvIGgWjnr/18nGE=; b=TiLMDIBiS/jlzQQ+rwUi5xeSqhxE8lRoYgpGQQEbBvYft7De7oHz+jrYtmWIrvlL2dZ95D VeLgWH8Xy/obp0lDe5lTm4YqNSbSe/JkyJUeLDGo5WX36NNV3qxt+ItGByLuSL7qhQ87es 9u8EtPYxU27jTWcSpK7lfHvSYXPJt7w= 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-61-fI44sw60N3C0hNH1bdmEJA-1; Thu, 08 Apr 2021 11:25:45 -0400 X-MC-Unique: fI44sw60N3C0hNH1bdmEJA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D75CE8189C8; Thu, 8 Apr 2021 15:25:41 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-119-35.rdu2.redhat.com [10.10.119.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7DD1710013C1; Thu, 8 Apr 2021 15:25:35 +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: <20210408145057.GN2531743@casper.infradead.org> References: <20210408145057.GN2531743@casper.infradead.org> <161789062190.6155.12711584466338493050.stgit@warthog.procyon.org.uk> <161789066013.6155.9816857201817288382.stgit@warthog.procyon.org.uk> To: Matthew Wilcox Cc: dhowells@redhat.com, linux-fsdevel@vger.kernel.org, Linus Torvalds , Alexander Viro , Christoph Hellwig , linux-mm@kvack.org, linux-cachefs@redhat.com, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, Trond Myklebust , Anna Schumaker , Steve French , Dominique Martinet , Jeff Layton , David Wysochanski , linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 02/30] mm: Add set/end/wait functions for PG_private_2 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <14839.1617895534.1@warthog.procyon.org.uk> Date: Thu, 08 Apr 2021 16:25:34 +0100 Message-ID: <14840.1617895534@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org Matthew Wilcox wrote: > > +void end_page_private_2(struct page *page) > > +{ > > + page = compound_head(page); > > + VM_BUG_ON_PAGE(!PagePrivate2(page), page); > > + clear_bit_unlock(PG_private_2, &page->flags); > > + wake_up_page_bit(page, PG_private_2); > > ... but when we try to end on a tail, we actually wake up the head ... Question is, should I remove compound_head() here or add it into the other functions? David