From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 13 Jan 2000 14:30:43 -0800 (PST) From: Linus Torvalds Subject: Re: [RFC] 2.3.39 zone balancing In-Reply-To: <200001132213.OAA37225@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: Alan Cox , Andrea Arcangeli , Rik van Riel , mingo@chiara.csoma.elte.hu, linux-mm@kvack.org, linux-kernel@vger.rutgers.edu List-ID: On Thu, 13 Jan 2000, Kanoj Sarcar wrote: > > Yes, that's what everyone seems to be pointing at. As I mentioned, I am > looking into this as I type. The only thing is, as Andrea points out, > 2.3 bh/irq handlers do not request HIGHMEM pages, so shouldn't the > 2.3 kswapd do something more like: > > more_work = 0; > for (i = 0; i < MAX_NR_ZONES; i++) { > if (i != ZONE_HIGHMEM) > more_work |= balance_zone(zone+i) No, the other reason for kswapd is to get "smoother" behaviour, by trying to keep some memory free. Also, while we don't use high-memory pages right now in BH and irq contexts, I don't think that is something we need to codify, and it may change in the future. There's no real reason per se for not using them (except for complexity), so I'd hate to have a special case for that case. Linus -- 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.nl.linux.org/Linux-MM/