From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx110.postini.com [74.125.245.110]) by kanga.kvack.org (Postfix) with SMTP id 8912B6B0072 for ; Tue, 6 Dec 2011 20:42:14 -0500 (EST) Received: by ghbg19 with SMTP id g19so54946ghb.14 for ; Tue, 06 Dec 2011 17:42:13 -0800 (PST) Date: Tue, 6 Dec 2011 17:42:10 -0800 (PST) From: David Rientjes Subject: Re: [patch v2]numa: add a sysctl to control interleave allocation granularity from each node In-Reply-To: <20111207013754.GA23364@sli10-conroe.sh.intel.com> Message-ID: References: <1323055846.22361.362.camel@sli10-conroe> <20111207013754.GA23364@sli10-conroe.sh.intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Shaohua Li Cc: lkml , linux-mm , Andrew Morton , "ak@linux.intel.com" , Jens Axboe , Christoph Lameter , "lee.schermerhorn@hp.com" On Wed, 7 Dec 2011, Shaohua Li wrote: > based on the allocation size, right? I did consider it. It would be easy to > implement this. Note even without my patch we have the issue if allocation > from one node is big order and small order from other node. And nobody > complains the imbalance. This makes me think maybe people didn't care > about the imbalance too much. > Right, I certainly see what you're trying to do and I support it, however, if we're going to add a userspace tunable then I think it would be better implemented as a size. You can still get the functionality that you have with your patch (just with a size of 0, the default, making every allocation on the next node) but can also interleave on PAGE_SIZE, HPAGE_SIZE, etc, increments. I think it would help for users who are concerned about node symmetry for contention on the memory bus and it would be a shame if someone needed to add a second tunable for that affect if your tunable already has applications using it. -- 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