From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx2.suse.de", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id BBEBF67A5D for ; Tue, 18 Apr 2006 03:11:44 +1000 (EST) From: Andi Kleen To: Nick Piggin Subject: Re: [PATCH 00/05] robust per_cpu allocation for modules Date: Mon, 17 Apr 2006 19:10:46 +0200 References: <1145049535.1336.128.camel@localhost.localdomain> <4441ECE6.5010709@yahoo.com.au> In-Reply-To: <4441ECE6.5010709@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200604171910.48838.ak@suse.de> Cc: Andrew Morton , linux-mips@linux-mips.org, David Mosberger-Tang , linux-ia64@vger.kernel.org, Martin Mares , spyro@f2s.com, Joe Taylor , linuxppc-dev@ozlabs.org, paulus@samba.org, benedict.gaster@superh.com, bjornw@axis.com, Ingo Molnar , grundler@parisc-linux.org, Steven Rostedt , starvik@axis.com, Linus Torvalds , Thomas Gleixner , rth@twiddle.net, Chris Zankel , tony.luck@intel.com, LKML , ralf@linux-mips.org, Marc Gauthier , lethal@linux-sh.org, schwidefsky@de.ibm.com, linux390@de.ibm.com, davem@davemloft.net, parisc-linux@parisc-linux.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sunday 16 April 2006 09:06, Nick Piggin wrote: > I still don't understand what the justification is for slowing down > this critical bit of infrastructure for something that is only a > problem in the -rt patchset, and even then only a problem when tracing > is enabled. There are actually problems outside -rt. e.g. the Xen kernel was running into a near overflow and as more and more code is using per cpu variables others might too. I'm confident the problem can be solved without adding more variables though - e.g. in the way rusty proposed. -Andi