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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 AD08BC282CE for ; Tue, 9 Apr 2019 10:30:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8483420883 for ; Tue, 9 Apr 2019 10:30:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727049AbfDIKah (ORCPT ); Tue, 9 Apr 2019 06:30:37 -0400 Received: from mga05.intel.com ([192.55.52.43]:25541 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726112AbfDIKag (ORCPT ); Tue, 9 Apr 2019 06:30:36 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Apr 2019 03:30:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,329,1549958400"; d="scan'208";a="141265265" Received: from smile.fi.intel.com (HELO smile) ([10.237.72.86]) by fmsmga007.fm.intel.com with ESMTP; 09 Apr 2019 03:30:32 -0700 Received: from andy by smile with local (Exim 4.92) (envelope-from ) id 1hDo1O-0001kx-Uq; Tue, 09 Apr 2019 13:30:30 +0300 Date: Tue, 9 Apr 2019 13:30:30 +0300 From: Andriy Shevchenko To: Christoph Hellwig Cc: Jacob Pan , iommu@lists.linux-foundation.org, LKML , Joerg Roedel , David Woodhouse , Alex Williamson , Jean-Philippe Brucker , Yi Liu , "Tian, Kevin" , Raj Ashok , Lu Baolu , "Paul E. McKenney" Subject: Re: [PATCH 01/18] drivers core: Add I/O ASID allocator Message-ID: <20190409103030.GK9224@smile.fi.intel.com> References: <1554767973-30125-1-git-send-email-jacob.jun.pan@linux.intel.com> <1554767973-30125-2-git-send-email-jacob.jun.pan@linux.intel.com> <20190409100049.GC9224@smile.fi.intel.com> <20190409100436.GA28683@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190409100436.GA28683@infradead.org> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 09, 2019 at 03:04:36AM -0700, Christoph Hellwig wrote: > On Tue, Apr 09, 2019 at 01:00:49PM +0300, Andriy Shevchenko wrote: > > I think it makes sense to add a helper macro to rcupdate.h > > (and we have several cases in kernel that can utilize it) > > > > #define kfree_non_null_rcu(ptr, rcu_head) \ > > do { \ > > if (ptr) \ > > kfree_rcu(ptr, rcu_head); \ > > } while (0) > > > > as a more common pattern for resource deallocators. > > I think that should move straight into kfree_rcu. Possible. I didn't dare to offer this due to lack of knowledge how it's used in other places. > In general > we expect *free* to deal with NULL pointers transparently, so we > should do so here as well. Exactly my point, thanks. -- With Best Regards, Andy Shevchenko