Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752827AbaKVALQ (ORCPT ); Fri, 21 Nov 2014 19:11:16 -0500 Received: from mail-qa0-f50.google.com ([209.85.216.50]:38457 "EHLO mail-qa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752608AbaKVALP (ORCPT ); Fri, 21 Nov 2014 19:11:15 -0500 Date: Fri, 21 Nov 2014 19:11:11 -0500 From: Tejun Heo To: Frederic Weisbecker Cc: Thomas Gleixner , Linus Torvalds , Dave Jones , Don Zickus , Linux Kernel , the arch/x86 maintainers , Peter Zijlstra , Andy Lutomirski , Arnaldo Carvalho de Melo Subject: Re: frequent lockups in 3.18rc4 Message-ID: <20141122001111.GA26007@htj.dyndns.org> References: <20141119235033.GE11386@lerouge> <20141120122339.GA14877@htj.dyndns.org> <20141120221122.GA25393@htj.dyndns.org> <20141120230514.GB25393@htj.dyndns.org> <20141121141332.GA8808@lerouge> <20141121162506.GA15461@htj.dyndns.org> <20141121214444.GB9198@lerouge> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141121214444.GB9198@lerouge> 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 Hello, Frederic. On Fri, Nov 21, 2014 at 10:44:46PM +0100, Frederic Weisbecker wrote: > I fear that enumerating and fix the existing issues won't be enough. > We can't find all the code sites out there which rely on not being > faulted. Oh, sure but that can take some time so adding documentation in the mean time probably isn't a bad idea. > The best would be to fix that from the percpu allocator itself, or > vmalloc. I don't think there's much percpu allocator itself can do. The ability to grow dynamically comes from being able to allocate relatively consistent layout among areas for different CPUs and pretty much requires vmalloc area and it'd generally be a good idea to take out the vmalloc fault anyway. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/