From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 23 Jun 2000 20:11:09 +0200 (CEST) From: Andrea Arcangeli Subject: Re: 2.4: why is NR_GFPINDEX so large? In-Reply-To: <200006222022.NAA47942@google.engr.sgi.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Kanoj Sarcar Cc: Timur Tabi , Linux MM mailing list List-ID: On Thu, 22 Jun 2000, Kanoj Sarcar wrote: >Umm, careful. If you happen to share a cacheline between a readonly array >and a frequently updated variable, it might be better not to delete >unused elements from an array - that way, you might be able to bunch up >all the frequently updated variables into their own cacheline, and save >the memory write back of an extra cacheline. I think on UP we shouldn't protect any read-only memory against somebody that isn't optimized. I think if there are a set of frequently updated variables, _they_ should care to live in the same cacheline (and they could also include in the same cacheline other stuff of course). It shouldn't be the gfpmask_zone array (that is read only) that cares to not include other stuff because there could be something not well optimized for cacheline flushes. >BTW, this is all of course nitpicking. Oh indeed but it's fun ;-) Andrea -- 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.eu.org/Linux-MM/