From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx159.postini.com [74.125.245.159]) by kanga.kvack.org (Postfix) with SMTP id 978A96B0033 for ; Sat, 6 Jul 2013 06:41:46 -0400 (EDT) Date: Sat, 6 Jul 2013 12:41:07 +0200 From: Peter Zijlstra Subject: Re: [PATCH 13/15] sched: Set preferred NUMA node based on number of private faults Message-ID: <20130706104107.GR18898@dyad.programming.kicks-ass.net> References: <1373065742-9753-1-git-send-email-mgorman@suse.de> <1373065742-9753-14-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1373065742-9753-14-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML On Sat, Jul 06, 2013 at 12:09:00AM +0100, Mel Gorman wrote: > +++ b/include/linux/mm.h > @@ -582,11 +582,11 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) > * sets it, so none of the operations on it need to be atomic. > */ > > -/* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_NID] | ... | FLAGS | */ > +/* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_NIDPID] | ... | FLAGS | */ > #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH) > #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH) > #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH) > -#define LAST_NID_PGOFF (ZONES_PGOFF - LAST_NID_WIDTH) > +#define LAST_NIDPID_PGOFF (ZONES_PGOFF - LAST_NIDPID_WIDTH) I saw the same with Ingo's patch doing the similar thing. But why do we fuse these two into a single field? Would it not make more sense to have them be separate fields? Yes I get we update and read them together, and we could still do that with appropriate helper function, but they are two independent values stored in the page flags. Its not something I care too much about, just something that strikes me as weird. -- 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