From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 244926B016A for ; Fri, 2 Sep 2011 03:22:39 -0400 (EDT) Subject: Re: [Xen-devel] Re: [Revert] Re: [PATCH] mm: sync vmalloc address space page tables in alloc_vm_area() From: Ian Campbell In-Reply-To: <4E5FED1A.1000300@goop.org> References: <1314877863-21977-1-git-send-email-david.vrabel@citrix.com> <20110901161134.GA8979@dumpdata.com> <4E5FED1A.1000300@goop.org> Content-Type: text/plain; charset="UTF-8" Date: Fri, 2 Sep 2011 08:22:34 +0100 Message-ID: <1314948154.28989.158.camel@zakaz.uk.xensource.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Jeremy Fitzhardinge Cc: Konrad Rzeszutek Wilk , "xen-devel@lists.xensource.com" , "namhyung@gmail.com" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , David Vrabel , "rientjes@google.com" , "akpm@linux-foundation.org" , "paulmck@linux.vnet.ibm.com" On Thu, 2011-09-01 at 21:37 +0100, Jeremy Fitzhardinge wrote: > On 09/01/2011 09:11 AM, Konrad Rzeszutek Wilk wrote: > > On Thu, Sep 01, 2011 at 12:51:03PM +0100, David Vrabel wrote: > >> From: David Vrabel > > Andrew, > > > > I was wondering if you would be Ok with this patch for 3.1. > > > > It is a revert (I can prepare a proper revert if you would like > > that instead of this patch). > > > > The users of this particular function (alloc_vm_area) are just > > Xen. There are no others. > > I'd prefer to put explicit vmalloc_sync_all()s in the callsites where > necessary, and ultimately try to work out ways of avoiding it altogether > (like have some hypercall wrapper which touches the arg memory to make > sure its mapped?). That only syncs the current pagetable though. If that is sufficient (and it could well be) then perhaps just doing a vmalloc_sync_one on the current page tables directly would be better than faulting to do it? It's the sort of thing you could hide inside the gnttab_set_map_op type helpers I guess? Ian. -- 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