From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 25 Sep 2000 15:30:50 +0200 From: Andrea Arcangeli Subject: Re: the new VM Message-ID: <20000925153050.C22882@athlon.random> References: <20000925150858.A22882@athlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from mingo@elte.hu on Mon, Sep 25, 2000 at 03:12:58PM +0200 Sender: owner-linux-mm@kvack.org Return-Path: To: Ingo Molnar Cc: Marcelo Tosatti , Linus Torvalds , Rik van Riel , Roger Larsson , MM mailing list , linux-kernel@vger.kernel.org List-ID: On Mon, Sep 25, 2000 at 03:12:58PM +0200, Ingo Molnar wrote: > well, i think all kernel-space allocations have to be limited carefully, When a machine without a gigabit ethernet runs oom it's userspace that allocated the memory via page faults not the kernel. And if the careful limit avoids the deadlock in the layer above alloc_pages, then it will also avoid alloc_pages to return NULL and you won't need an infinite loop in first place (unless the memory balancing is buggy). GFP should return NULL only if the machine is out of memory. The kernel can be written in a way that never deadlocks when the machine is out of memory just checking the GFP retval. I don't think any in-kernel resource limit is necessary to have things reliable and fast. Most dynamic big caches and kernel data can be shrinked dynamically during memory pressure (pheraps except skbs and I agree that for skbs on gigabit ethernet the thing is a little different). 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/