From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 2 Oct 2006 00:05:11 -0700 (PDT) From: David Rientjes Subject: Re: [RFC] another way to speed up fake numa node page_alloc In-Reply-To: <20061001234858.fe91109e.pj@sgi.com> Message-ID: References: <20060925091452.14277.9236.sendpatchset@v0> <20061001231811.26f91c47.pj@sgi.com> <20061001234858.fe91109e.pj@sgi.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Jackson Cc: linux-mm@kvack.org, akpm@osdl.org, nickpiggin@yahoo.com.au, ak@suse.de, mbligh@google.com, rohitseth@google.com, menage@google.com, clameter@sgi.com List-ID: On Sun, 1 Oct 2006, Paul Jackson wrote: > I'm not sure what you have in mind by "scale this." > I'm talking about this: +struct zonelist_faster { + nodemask_t fullnodes; /* nodes recently lacking free memory */ + unsigned long last_full_zap; /* jiffies when fullnodes last zero'd */ + unsigned short node_id[MAX_NUMNODES * MAX_NR_ZONES]; /* zone -> nid */ +}; With NODES_SHIFT equal to 10 as you recommend, you can't get away with an unsigned short there. Likewise, your nodemask_t would need to be 128 bytes. So this doesn't scale appropriately when you simply change NODES_SHIFT. > This speedup should apply regardless of how many nodes (fake or > real or mixed) are present. > It doesn't (see above). > But whatever benefit this proposal has should be independent of the > value of NODES_SHIFT. > It's not (see above). David -- 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