From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id C6C406B0278 for ; Mon, 12 Feb 2018 12:36:53 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id d63so2651611wma.4 for ; Mon, 12 Feb 2018 09:36:53 -0800 (PST) Received: from casper.infradead.org (casper.infradead.org. [2001:8b0:10b:1236::1]) by mx.google.com with ESMTPS id p203si4095529wmb.227.2018.02.12.09.36.52 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 12 Feb 2018 09:36:52 -0800 (PST) Date: Mon, 12 Feb 2018 09:36:30 -0800 From: Matthew Wilcox Subject: Re: [RFC] Protect larger order pages from breaking up Message-ID: <20180212173630.GB9396@bombadil.infradead.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Christopher Lameter Cc: Mel Gorman , linux-mm@kvack.org, akpm@linux-foundation.org, Leon Romanovsky , linux-rdma@vger.kernel.org, Thomas Schoebel-Theuer On Fri, Feb 09, 2018 at 01:24:41PM -0600, Christopher Lameter wrote: > Control over this feature is by writing to /proc/zoneinfo. > > F.e. to ensure that 2000 16K pages stay available for jumbo > frames do > > echo "3=2000" >/proc/zoneinfo That seems ... wrong. 4k is order 0, 8k is order 1, 16k is order 2, 32k is order 3. > One can then also f.e. operate the slub allocator with > 64k pages. Specify "slub_max_order=3 slub_min_order=3" on > the kernel command line and all slab allocator allocations > will occur in 16K page sizes. This example also reads weird ;-) -- 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