Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752109AbXAZMbx (ORCPT ); Fri, 26 Jan 2007 07:31:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752097AbXAZMbx (ORCPT ); Fri, 26 Jan 2007 07:31:53 -0500 Received: from lucidpixels.com ([75.144.35.66]:57692 "EHLO lucidpixels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752022AbXAZMbw (ORCPT ); Fri, 26 Jan 2007 07:31:52 -0500 Date: Fri, 26 Jan 2007 07:31:50 -0500 (EST) From: Justin Piszcz X-X-Sender: jpiszcz@p34.internal.lan To: Andrew Morton cc: Chuck Ebbert , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, xfs@oss.sgi.com, Neil Brown Subject: Re: Kernel 2.6.19.2 New RAID 5 Bug (oops when writing Samba -> RAID5) In-Reply-To: <20070126012505.d8cb07f2.akpm@osdl.org> Message-ID: References: <45B5261B.1050104@redhat.com> <20070126012505.d8cb07f2.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2636 Lines: 84 Just re-ran the test 4-5 times, could not reproduce this one, but I'll keep running this kernel w/patch for a while and see if it happens again. On Fri, 26 Jan 2007, Andrew Morton wrote: > On Wed, 24 Jan 2007 18:37:15 -0500 (EST) > Justin Piszcz wrote: > > > > Without digging too deeply, I'd say you've hit the same bug Sami Farin and > > > others > > > have reported starting with 2.6.19: pages mapped with kmap_atomic() become > > > unmapped > > > during memcpy() or similar operations. Try disabling preempt -- that seems to > > > be the > > > common factor. > > > > > > > > > - > > > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > > > the body of a message to majordomo@vger.kernel.org > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > > > > > > After I run some other tests, I am going to re-run this test and see if it > > OOPSes again with PREEMPT off. > > Strange. The below debug patch might catch it - please run with this > applied. > > > --- a/arch/i386/mm/highmem.c~kmap_atomic-debugging > +++ a/arch/i386/mm/highmem.c > @@ -30,7 +30,43 @@ void *kmap_atomic(struct page *page, enu > { > enum fixed_addresses idx; > unsigned long vaddr; > + static unsigned warn_count = 10; > > + if (unlikely(warn_count == 0)) > + goto skip; > + > + if (unlikely(in_interrupt())) { > + if (in_irq()) { > + if (type != KM_IRQ0 && type != KM_IRQ1 && > + type != KM_BIO_SRC_IRQ && type != KM_BIO_DST_IRQ && > + type != KM_BOUNCE_READ) { > + WARN_ON(1); > + warn_count--; > + } > + } else if (!irqs_disabled()) { /* softirq */ > + if (type != KM_IRQ0 && type != KM_IRQ1 && > + type != KM_SOFTIRQ0 && type != KM_SOFTIRQ1 && > + type != KM_SKB_SUNRPC_DATA && > + type != KM_SKB_DATA_SOFTIRQ && > + type != KM_BOUNCE_READ) { > + WARN_ON(1); > + warn_count--; > + } > + } > + } > + > + if (type == KM_IRQ0 || type == KM_IRQ1 || type == KM_BOUNCE_READ) { > + if (!irqs_disabled()) { > + WARN_ON(1); > + warn_count--; > + } > + } else if (type == KM_SOFTIRQ0 || type == KM_SOFTIRQ1) { > + if (irq_count() == 0 && !irqs_disabled()) { > + WARN_ON(1); > + warn_count--; > + } > + } > +skip: > /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ > pagefault_disable(); > if (!PageHighMem(page)) > _ > - 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/