From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934747AbbEOVxu (ORCPT ); Fri, 15 May 2015 17:53:50 -0400 Received: from eddie.linux-mips.org ([148.251.95.138]:40542 "EHLO cvs.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964787AbbEOVxt (ORCPT ); Fri, 15 May 2015 17:53:49 -0400 Date: Fri, 15 May 2015 23:53:21 +0200 From: Ralf Baechle To: Leonid Yegoshin Cc: aleksey.makarov@auriga.com, james.hogan@imgtec.com, paul.burton@imgtec.com, david.daney@cavium.com, peterz@infradead.org, linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, davidlohr@hp.com, kirill@shutemov.name, akpm@linux-foundation.org, mingo@kernel.org Subject: Re: [PATCH v2] MIPS64: Support of at least 48 bits of SEGBITS Message-ID: <20150515215320.GI2322@linux-mips.org> References: <20150515013351.7450.12130.stgit@ubuntu-yegoshin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150515013351.7450.12130.stgit@ubuntu-yegoshin> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 14, 2015 at 06:34:43PM -0700, Leonid Yegoshin wrote: The order 1 allocation for the PGD are concerning me a little. On a system under even moderate memory pressure that might become a bit of a reliability or performance issue. With 4kB pages we already need order 1 or even 2 allocations for the allocation of the stack and some folks have reported that to be an issue so we may have to start using the PUD for very large VA spaces. Ralf