Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S939019AbcLVWPg (ORCPT ); Thu, 22 Dec 2016 17:15:36 -0500 Received: from ipmail05.adl6.internode.on.net ([150.101.137.143]:5574 "EHLO ipmail05.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757475AbcLVWPf (ORCPT ); Thu, 22 Dec 2016 17:15:35 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2CUDgA1UFxYIOyiLHleGgEBAQECAQEBAQgBAQEBgzUBAQEBAR+BZoJ+g3mGWnKUOAEBAQEBB4EcjDiED4ROggmGHAICAQECgWtAFAECAQEBAQEBAQYBAQEBAQE5RUIShBQBAQEDATocIwULCAMYCSUPBSUDBxoTiGAFB602iwABAQgCASUghWOFJ4E/AYhrBZp4kS2QX0mNXYQPHzeBCBYNhCMngVkqNIIshj0BAQE Date: Fri, 23 Dec 2016 09:15:00 +1100 From: Dave Chinner To: Linus Torvalds Cc: Jens Axboe , Thomas Gleixner , Ingo Molnar , Peter Anvin , Linux Kernel Mailing List , the arch/x86 maintainers Subject: Re: [4.10, panic, regression] iscsi: null pointer deref at iscsi_tcp_segment_done+0x20d/0x2e0 Message-ID: <20161222221500.GL4758@dastard> References: <20161216185906.t2wmrr6wqjdsrduw@straylight.hirudinean.org> <20161221221638.GD4758@dastard> <20161222001303.nvrtm22szn3hgxar@straylight.hirudinean.org> <20161222051322.GF4758@dastard> <20161222062858.GG4758@dastard> <20161222204240.GJ4758@dastard> <20161222210607.GK4758@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1018 Lines: 28 On Thu, Dec 22, 2016 at 01:10:19PM -0800, Linus Torvalds wrote: > Ok, so the numa issue was a red herring. With that fixed: > > On Thu, Dec 22, 2016 at 1:06 PM, Dave Chinner wrote: > > > > Better, but still bad. average files/s is not up to 200k files/s, > > so still a good 10-15% off where it should be. xfs_repair is back > > down to 10-15% off where it should be, too. bulkstat still fires off > > a bad page reference count warning, iscsi still panics immediately. > > Do you have CONFIG_BLK_WBT enabled, perhaps? Ok, yes, that's enabled. Let me go turn it off and see what happens. > It's new to this merge window, and I'm not convinced it's been tuned. > Particularly for your kinds of fairly extreme IO loads. Well, these aren't extreme IO workloads. Yes, the filesystem does a lot of work on the CPU, but the IO loads XFS generates aren't particularly high - maybe 2-3000 IOPS at most, and mostly the bandwidth is below 100MB/s. Cheers, Dave. -- Dave Chinner david@fromorbit.com