From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [PATCH v4 1/3] make jump_labels wait while updates are in place Date: Fri, 27 Apr 2012 10:07:10 -0400 Message-ID: <1335535630.28106.209.camel@gandalf.stny.rr.com> References: <1335480667-8301-1-git-send-email-glommer@parallels.com> <1335480667-8301-2-git-send-email-glommer@parallels.com> <20120427004305.GC23877@home.goodmis.org> <20120427135320.GA13762@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 7bit Cc: Glauber Costa , cgroups@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Li Zefan , Tejun Heo , kamezawa.hiroyu@jp.fujitsu.com, linux-mm@kvack.org, devel@openvz.org, Johannes Weiner , Michal Hocko , Ingo Molnar To: Jason Baron Return-path: In-Reply-To: <20120427135320.GA13762@redhat.com> Sender: owner-linux-mm@kvack.org List-Id: netdev.vger.kernel.org On Fri, 2012-04-27 at 09:53 -0400, Jason Baron wrote: > Right, for x86 which uses stop_machine currently, we guarantee that all > cpus are going to see the updated code, before the inc of key->enabled. > However, other arches (sparc, mips, powerpc, for example), seem to be > using much lighter weight updates, which I hope are ok :) And x86 will soon be removing stop_machine() from its path too. But all archs should perform some kind of memory sync after patching code. Thus the update should be treated as if a memory barrier was added after it, and before the inc. -- Steve -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org