From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id DFB106B0005 for ; Tue, 5 Jul 2016 02:22:25 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id a69so430746702pfa.1 for ; Mon, 04 Jul 2016 23:22:25 -0700 (PDT) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTP id k26si2600113pfk.85.2016.07.04.23.22.23 for ; Mon, 04 Jul 2016 23:22:25 -0700 (PDT) Date: Tue, 5 Jul 2016 14:22:22 +0800 From: Aaron Lu Subject: Re: [RFC RESEND PATCH] swap: choose swap device according to numa node Message-ID: <20160705062221.GA12620@aaronlu.sh.intel.com> References: <20160429083408.GA20728@aaronlu.sh.intel.com> <263e604d-aa8c-1b6b-e80a-0c34142349c9@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Yu Chen Cc: Linux Memory Management List , "linux-kernel@vger.kernel.org" On Tue, Jul 05, 2016 at 01:57:35PM +0800, Yu Chen wrote: > On Tue, Jul 5, 2016 at 11:19 AM, Aaron Lu wrote: > > Resend: > > This is a resend, the original patch doesn't catch much attention. > > It may not be a big deal for swap devices that used to be hosted on > > HDD but with devices like 3D Xpoint to be used as swap device, it could > > make a real difference if we consider NUMA information when doing IO. > > Comments are appreciated, thanks for your time. > > > -------------------------%<------------------------- > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index 71b1c29948db..dd7e44a315b0 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -3659,9 +3659,11 @@ void kswapd_stop(int nid) > > > > static int __init kswapd_init(void) > > { > > - int nid; > > + int nid, err; > > > > - swap_setup(); > > + err = swap_setup(); > > + if (err) > > + return err; > > for_each_node_state(nid, N_MEMORY) > > kswapd_run(nid); > > hotcpu_notifier(cpu_callback, 0); > In original implementation, although swap_setup failed, In current implementaion swap_setup never fail :-) > the swapd would also be created, since swapd is > not only used for swap out but also for other page reclaim, > so this change above might modify its semantic? Sorry if > I understand incorrectly. Indeed it's a behaviour change. The only reason swap_setup can return an error code now is when it fails to allocate nr_node_ids * sizeof(struct plist_head) memory and if that happens, I don't think it makes much sense to continue boot the system. Thanks, Aaron -- 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