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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 8109AC282CE for ; Tue, 9 Apr 2019 10:04:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4772D20857 for ; Tue, 9 Apr 2019 10:04:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="YBZTCpib" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726725AbfDIKEl (ORCPT ); Tue, 9 Apr 2019 06:04:41 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:37184 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726079AbfDIKEk (ORCPT ); Tue, 9 Apr 2019 06:04:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ECN5RtyAoOFeKS2bytXLHxuqXCY8zXSsiaFPh0hQOLE=; b=YBZTCpibRaLdOoYWUhK9zEG/0 BTqM90ug44ilMFjAoeZSG1zHMsGuzCmfCw6zMxBSVSwaiUxPPEttp+BVD4PxBgWkTUiWkcouLTNkm 3cO3mpOjPHaR+Yh1aXQSmj6s7qR8TCRY9N+dyrq4ShyJKFS2Dx7AsXv29PHt9l+Uwpy5vB3fsc3lZ oDu5i+lPtNXqjsNhQ6B4NIrREIcorgn7GuD4o2shm/2Fr4J4b+kNvFVKsnR+9p+9nP/hmcJKHh73X bUx5+sib41bVfh8IjO4ycM+bzbqA0x53BifGUJRfr+4NAB7f1nj5WebbWG0HqYZhIw+ANg3On6m0Z +SoGUUkRg==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1hDncK-0007WU-W6; Tue, 09 Apr 2019 10:04:36 +0000 Date: Tue, 9 Apr 2019 03:04:36 -0700 From: Christoph Hellwig To: Andriy Shevchenko Cc: Jacob Pan , iommu@lists.linux-foundation.org, LKML , Joerg Roedel , David Woodhouse , Alex Williamson , Jean-Philippe Brucker , Yi Liu , "Tian, Kevin" , Raj Ashok , Christoph Hellwig , Lu Baolu , "Paul E. McKenney" Subject: Re: [PATCH 01/18] drivers core: Add I/O ASID allocator Message-ID: <20190409100436.GA28683@infradead.org> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190409100049.GC9224@smile.fi.intel.com> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html 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 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. In general we expect *free* to deal with NULL pointers transparently, so we should do so here as well.