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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AFB2C43217 for ; Mon, 16 May 2022 20:09:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241399AbiEPUJI (ORCPT ); Mon, 16 May 2022 16:09:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350021AbiEPUAp (ORCPT ); Mon, 16 May 2022 16:00:45 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F053A45AC7; Mon, 16 May 2022 12:54:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1652730891; x=1684266891; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=fScrN08znRDZaq3DWOz2/SzfYqSDlpSGins4k3VDQok=; b=C8vYxgEMQEXCfuZ2a8yqVSQ0BC12xHGEhkOND/PbkXlE0SpPHcoJXNzW MnYO9PhcBwK1BbolpV3g0sB+JllxsEh6fzlK4x2JDenD08emyZ7ZC1Cg5 eD9Myq/CD1N4Tnzn5ydKCIzJk6rv+oYjGDbo79TzCwtKW2ZzIi0W8vZ+2 q6eaABVq2wGqvxppv1EkTWqEEygLwqnR+K4fFC3RUQ9UwJZ4VXW3OUwXZ jz9sX4f1X5u/PetbjRxx3qs1EW/qbe8oSoImr3Km/IXwsBOQ38jmO1HKg qxdPmVeLnvaBNVAPZBzCGBIsv/aR/HWs549P2GqzF0gZajeqA6oLU+480 A==; X-IronPort-AV: E=McAfee;i="6400,9594,10349"; a="333990653" X-IronPort-AV: E=Sophos;i="5.91,230,1647327600"; d="scan'208";a="333990653" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 May 2022 12:53:55 -0700 X-IronPort-AV: E=Sophos;i="5.91,230,1647327600"; d="scan'208";a="568501950" Received: from csalmon-mobl.amr.corp.intel.com (HELO localhost) ([10.212.118.70]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 May 2022 12:53:54 -0700 Date: Mon, 16 May 2022 12:53:54 -0700 From: Ira Weiny To: Matthew Wilcox Cc: "Fabio M. De Francesco" , Evgeniy Dushistov , Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] fs/ufs: Replace kmap() with kmap_local_page() Message-ID: References: <20220516101925.15272-1-fmdefrancesco@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, May 16, 2022 at 03:55:54PM +0100, Matthew Wilcox wrote: > On Mon, May 16, 2022 at 12:19:25PM +0200, Fabio M. De Francesco wrote: > > The use of kmap() is being deprecated in favor of kmap_local_page(). With > > kmap_local_page(), the mapping is per thread, CPU local and not globally > > visible. > > > > The usage of kmap_local_page() in fs/ufs is pre-thread, therefore replace > > kmap() / kunmap() calls with kmap_local_page() / kunmap_local(). > > > > kunmap_local() requires the mapping address, so return that address from > > ufs_get_page() to be used in ufs_put_page(). > > > > These changes are essentially ported from fs/ext2 and are largely based on > > commit 782b76d7abdf ("fs/ext2: Replace kmap() with kmap_local_page()"). > > > > Suggested-by: Ira Weiny > > Reviewed-by: Ira Weiny > > Signed-off-by: Fabio M. De Francesco > > Have you done more than compile-tested this? I'd like to know that it's > been tested on a machine with HIGHMEM enabled (in a VM, presumably). > UFS doesn't get a lot of testing, and it'd be annoying to put out a > patch that breaks the kmap_local() rules. I'm not against trying to test. But did you see a place which might break the kmap_local() rules? Ira