From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f175.google.com (mail-wi0-f175.google.com [209.85.212.175]) by kanga.kvack.org (Postfix) with ESMTP id 3B35F6B0035 for ; Thu, 29 May 2014 20:29:45 -0400 (EDT) Received: by mail-wi0-f175.google.com with SMTP id f8so218680wiw.14 for ; Thu, 29 May 2014 17:29:44 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id eb1si1034406wic.29.2014.05.29.17.29.42 for ; Thu, 29 May 2014 17:29:43 -0700 (PDT) Date: Thu, 29 May 2014 20:29:19 -0400 From: Dave Jones Subject: Re: [RFC 2/2] x86_64: expand kernel stack to 16K Message-ID: <20140530002919.GA30913@redhat.com> References: <20140528223142.GO8554@dastard> <20140529013007.GF6677@dastard> <20140529072633.GH6677@dastard> <20140529235308.GA14410@dastard> <20140530000649.GA3477@redhat.com> <20140530002113.GC14410@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140530002113.GC14410@dastard> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Chinner Cc: Linus Torvalds , Jens Axboe , Minchan Kim , Linux Kernel Mailing List , Andrew Morton , linux-mm , "H. Peter Anvin" , Ingo Molnar , Peter Zijlstra , Mel Gorman , Rik van Riel , Johannes Weiner , Hugh Dickins , Rusty Russell , "Michael S. Tsirkin" , Dave Hansen , Steven Rostedt On Fri, May 30, 2014 at 10:21:13AM +1000, Dave Chinner wrote: > On Thu, May 29, 2014 at 08:06:49PM -0400, Dave Jones wrote: > > On Fri, May 30, 2014 at 09:53:08AM +1000, Dave Chinner wrote: > > > > > That sounds like a plan. Perhaps it would be useful to add a > > > WARN_ON_ONCE(stack_usage > 8k) (or some other arbitrary depth beyond > > > 8k) so that we get some indication that we're hitting a deep stack > > > but the system otherwise keeps functioning. That gives us some > > > motivation to keep stack usage down but isn't a fatal problem like > > > it is now.... > > > > We have check_stack_usage() and DEBUG_STACK_USAGE for this. > > Though it needs some tweaking if we move to 16K > > Right, but it doesn't throw loud warnings when a specific threshold > is reached - it just issues a quiet message when a process exits > telling you what the maximum was without giving us a stack to chew > on.... ah, right good point. That would be more useful. Dave -- 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