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 B19F9C4363A for ; Wed, 28 Oct 2020 22:07:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 497AB20639 for ; Wed, 28 Oct 2020 22:07:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TkJlsHOT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730078AbgJ1WHW (ORCPT ); Wed, 28 Oct 2020 18:07:22 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:50829 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729419AbgJ1WHR (ORCPT ); Wed, 28 Oct 2020 18:07:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603922836; 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=O/BGLtzgfmF0SgLWDxB+OjnwScbwNx4rvirjwHvdxu8=; b=TkJlsHOTF19GsnnXXudJHW4flnIJnzy0DkLPUg/kXTVgZFpykQyE6mXFMnw6GszPbgzuS5 xrfI7YNWrzphNXRbfNvUomCAO1VV7xB2Sx6+eJIuSRl8P8685ZLDYlT/7TyylM9wuCbvNK 7t2QOTHdzUL0+oKAAozxaavUq5bNHJ8= 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-356-w0Cal7W0O1KKXv-zA7kNsg-1; Wed, 28 Oct 2020 13:05:11 -0400 X-MC-Unique: w0Cal7W0O1KKXv-zA7kNsg-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 2F60B802B66; Wed, 28 Oct 2020 17:05:10 +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 1511D100164C; Wed, 28 Oct 2020 17:05:08 +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: <20201028143442.GA20115@casper.infradead.org> References: <20201028143442.GA20115@casper.infradead.org> <160389418807.300137.8222864749005731859.stgit@warthog.procyon.org.uk> <160389426655.300137.17487677797144804730.stgit@warthog.procyon.org.uk> To: Matthew Wilcox Cc: dhowells@redhat.com, linux-afs@lists.infradead.org, kernel test robot , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 11/11] afs: Fix dirty-region encoding on ppc32 with 64K pages MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <548208.1603904708.1@warthog.procyon.org.uk> Date: Wed, 28 Oct 2020 17:05:08 +0000 Message-ID: <548209.1603904708@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Matthew Wilcox wrote: > > +{ > > + if (PAGE_SIZE - 1 <= __AFS_PAGE_PRIV_MASK) > > + return 1; > > + else > > + return PAGE_SIZE / (__AFS_PAGE_PRIV_MASK + 1); > > Could this be DIV_ROUND_UP(PAGE_SIZE, __AFS_PAGE_PRIV_MASK + 1); avoiding > a conditional? I appreciate it's calculated at compile time today, but > it'll be dynamic with THP. Hmmm - actually, I want a shift size, not a number of bytes as I divide by it twice in afs_page_dirty(). David