From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 2556A6B02DD for ; Wed, 7 Feb 2018 02:54:20 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id z83so370721wmc.5 for ; Tue, 06 Feb 2018 23:54:20 -0800 (PST) Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net. [2001:4b98:c:538::195]) by mx.google.com with ESMTPS id j136si855965wmd.184.2018.02.06.23.54.18 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Feb 2018 23:54:18 -0800 (PST) Date: Tue, 6 Feb 2018 23:54:09 -0800 From: Josh Triplett Subject: Re: [PATCH 0/2] rcu: Transform kfree_rcu() into kvfree_rcu() Message-ID: <20180207075409.GA5726@localhost> References: <151791170164.5994.8253310844733420079.stgit@localhost.localdomain> <20180207021703.GC3617@linux.vnet.ibm.com> <20180207042334.GA16175@bombadil.infradead.org> <20180207050200.GH3617@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180207050200.GH3617@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Paul E. McKenney" Cc: Matthew Wilcox , Kirill Tkhai , rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, mingo@redhat.com, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, brouer@redhat.com, rao.shoaib@oracle.com On Tue, Feb 06, 2018 at 09:02:00PM -0800, Paul E. McKenney wrote: > On Tue, Feb 06, 2018 at 08:23:34PM -0800, Matthew Wilcox wrote: > > On Tue, Feb 06, 2018 at 06:17:03PM -0800, Paul E. McKenney wrote: > > > So it is OK to kvmalloc() something and pass it to either kfree() or > > > kvfree(), and it had better be OK to kvmalloc() something and pass it > > > to kvfree(). > > > > > > Is it OK to kmalloc() something and pass it to kvfree()? > > > > Yes, it absolutely is. > > > > void kvfree(const void *addr) > > { > > if (is_vmalloc_addr(addr)) > > vfree(addr); > > else > > kfree(addr); > > } > > > > > If so, is it really useful to have two different names here, that is, > > > both kfree_rcu() and kvfree_rcu()? > > > > I think it's handy to have all three of kvfree_rcu(), kfree_rcu() and > > vfree_rcu() available in the API for the symmetry of calling kmalloc() > > / kfree_rcu(). > > > > Personally, I would like us to rename kvfree() to just free(), and have > > malloc(x) be an alias to kvmalloc(x, GFP_KERNEL), but I haven't won that > > fight yet. > > But why not just have the existing kfree_rcu() API cover both kmalloc() > and kvmalloc()? Perhaps I am not in the right forums, but I am not hearing > anyone arguing that the RCU API has too few members. ;-) I don't have any problem with having just `kvfree_rcu`, but having just `kfree_rcu` seems confusingly asymmetric. (Also, count me in favor of having just one "free" function, too.) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org