From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755643AbYGMSyA (ORCPT ); Sun, 13 Jul 2008 14:54:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754468AbYGMSxx (ORCPT ); Sun, 13 Jul 2008 14:53:53 -0400 Received: from mail4.aster.pl ([212.76.33.58]:15108 "EHLO mail4.aster.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753834AbYGMSxw convert rfc822-to-8bit (ORCPT ); Sun, 13 Jul 2008 14:53:52 -0400 From: "Jakub W. Jozwicki" To: Jeremy Fitzhardinge Subject: Re: [PATCH 2.6.25.10 1/2] libata: fix locking for kmap_atomic Date: Sun, 13 Jul 2008 20:53:29 +0200 User-Agent: KMail/1.9.9 Cc: Andrew Morton , linux-kernel@vger.kernel.org, mingo@elte.hu, tglx@timesys.com References: <200807130127.36706.jozwicki@aster.pl> <200807131517.51795.jozwicki@aster.pl> <487A3F75.5010405@goop.org> In-Reply-To: <487A3F75.5010405@goop.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200807132053.30849.jozwicki@aster.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sunday, 13 of July 2008 19:46:29 Jeremy Fitzhardinge napisał(a): > Jakub W. Jozwicki wrote: > > Sorry, this was for -rt only. > > > > [ 17.012011] BUG: sleeping function called from invalid context > > IRQ-14(5732) at arch/x86/mm/highmem_32.c:8 > > [ 17.012011] in_atomic():0 [00000000], irqs_disabled():1 > > [ 17.012011] Pid: 5732, comm: IRQ-14 Not tainted 2.6.25.10-rtXXX #11 > > [ 17.012011] [] __might_sleep+0xf1/0xf8 > > [ 17.012011] [] kmap+0x47/0x5a > > The subject says kmap_atomic, but this is kmap. It definitely makes no > sense to call kmap in an IRQ, regardless of the locking. There seems to > be a larger structural problem here. > --- linux-2.6.25.8-rt7.orig/include/asm-x86/highmem.h 2008-06-23 19:12:47.000000000 -0400 +++ linux-2.6.25.8-rt7/include/asm-x86/highmem.h 2008-06-23 19:13:58.000000000 -0400 +/* + * on PREEMPT_RT kmap_atomic() is a wrapper that uses kmap(): + */ +#ifdef CONFIG_PREEMPT_RT +# define kmap_atomic_prot(page, type, prot) ({ pagefault_disable(); kmap(page); }) +# define kmap_atomic(page, type) ({ pagefault_disable(); kmap(page); }) +# define kmap_atomic_pfn(pfn, type) kmap(pfn_to_page(pfn)) +# define kunmap_atomic(kvaddr, type) do { pagefault_enable(); kunmap_virt(kvaddr); } while(0) +# define kmap_atomic_to_page(kvaddr) kmap_to_page(kvaddr) +#else +# define kmap_atomic_prot(page, type, prot) __kmap_atomic_prot(page, type, prot) +# define kmap_atomic(page, type) __kmap_atomic(page, type) +# define kmap_atomic_pfn(pfn, type) __kmap_atomic_pfn(pfn, type) +# define kunmap_atomic(kvaddr, type) __kunmap_atomic(kvaddr, type) +# define kmap_atomic_to_page(kvaddr) __kmap_atomic_to_page(kvaddr) +#endif +