From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andriy Shevchenko Subject: Re: [PATCH 01/18] drivers core: Add I/O ASID allocator Date: Tue, 9 Apr 2019 13:30:30 +0300 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 Return-path: Content-Disposition: inline In-Reply-To: <20190409100436.GA28683@infradead.org> Sender: linux-kernel-owner@vger.kernel.org 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" List-Id: iommu@lists.linux-foundation.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 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,URIBL_BLOCKED,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 61C54C10F0E for ; Tue, 9 Apr 2019 10:30:38 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3697120830 for ; Tue, 9 Apr 2019 10:30:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3697120830 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id F10B1FE6; Tue, 9 Apr 2019 10:30:37 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id D4E8BFDC for ; Tue, 9 Apr 2019 10:30:36 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 85A62F4 for ; Tue, 9 Apr 2019 10:30:36 +0000 (UTC) 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 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-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) Cc: "Tian, Kevin" , Raj Ashok , Jean-Philippe Brucker , iommu@lists.linux-foundation.org, LKML , Alex Williamson , "Paul E. McKenney" , David Woodhouse X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Message-ID: <20190409103030.4dgCEAhbiuQC9nRQQZPSthxe4J0bm4OBSdEhUYrnr0I@z> 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 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu