Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756849AbaDHUbi (ORCPT ); Tue, 8 Apr 2014 16:31:38 -0400 Received: from mout.gmx.net ([212.227.15.19]:56083 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756207AbaDHUbg (ORCPT ); Tue, 8 Apr 2014 16:31:36 -0400 Message-ID: <53445BEA.1060702@gmx.de> Date: Tue, 08 Apr 2014 22:28:26 +0200 From: =?UTF-8?B?VG9yYWxmIEbDtnJzdGVy?= User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Peter Zijlstra CC: Michele Ballabio , linux-kernel@vger.kernel.org, fweisbec@gmail.com, mingo@kernel.org, Steven Rostedt , David Cohen , Stefan Bader , Paolo Bonzini , Borislav Petkov Subject: Re: Bisected KVM hang on x86-32 between v3.12 and v3.13 References: <5341707F.5000406@katamail.com> <20140407150337.GO10526@twins.programming.kicks-ass.net> <20140407150705.GB13658@twins.programming.kicks-ass.net> <5342EB78.3060002@gmx.de> <20140407185658.GK11096@twins.programming.kicks-ass.net> <20140408122128.GC13658@twins.programming.kicks-ass.net> In-Reply-To: <20140408122128.GC13658@twins.programming.kicks-ass.net> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Provags-ID: V03:K0:GMC+NsjYx7ElxZwg8DJ8mrlieA7OJDSRSehLYoM4YiJrQet+BFK 0Qn0GWxKVGjl+NUJ6DAA9rOUw9iNPE4b84n4eOiq1KlJKVCdceH62rgB1PeFnQtTKNTaFYb d2nn3ZzN3KiJ35z2hHLfQE2fGo+tmOHW630jPBEtyLMX1AR/jnkJn3AdRlJwg2T0wnIhUsw IVsy+0tXHNCNN+xkhWPHg== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 04/08/2014 02:21 PM, Peter Zijlstra wrote: > On Mon, Apr 07, 2014 at 08:56:58PM +0200, Peter Zijlstra wrote: >> On Mon, Apr 07, 2014 at 08:16:24PM +0200, Toralf Förster wrote: >> >>> v3.14-10353-g2b3a8fd works fine AFAICS (BTW the fix is stable >>> material, right ?) >> >> I'm fairly sure its not; its a rather invasive series; see: >> >> 2432e1364bbe x86: Nuke the supervisor_stack field in i386 >> thread_info b807902a88c4 x86: Nuke GET_THREAD_INFO_WITH_ESP() >> macro for i386 0788aa6a23cb x86: Prepare removal of previous_esp >> from i386 thread_info structure 198d208df437 x86: Keep >> thread_info on thread stack in x86_32 >> >> Let me see if there's anything 'simpler' we can stuff in .13+ > > OK.. so could someone test the below patch to see if that makes > things work for .13 and .14? > patch applied on 3.1.3.9 and 3.14.0 it fixed the issue AFAICT > --- arch/x86/include/asm/preempt.h | 11 +++++++++++ > include/linux/preempt.h | 4 ++++ > include/linux/thread_info.h | 2 -- 3 files changed, 15 > insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/preempt.h > b/arch/x86/include/asm/preempt.h index c8b051933b1b..7ada46d8d4d8 > 100644 --- a/arch/x86/include/asm/preempt.h +++ > b/arch/x86/include/asm/preempt.h @@ -5,6 +5,17 @@ #include > #include > > +#ifdef CONFIG_X86_32 +/* + * i386's current_thread_info() depends > on ESP and for interrupt/exception + * stacks this doesn't yield > the actual task thread_info. + * + * We hard rely on the fact that > all the TIF_NEED_RESCHED bits are + * the same, therefore use the > slightly more expensive version below. + */ +#define > tif_need_resched() test_tsk_thread_flag(current, TIF_NEED_RESCHED) > +#endif + DECLARE_PER_CPU(int, __preempt_count); > > /* diff --git a/include/linux/preempt.h b/include/linux/preempt.h > index de83b4eb1642..891c8f8b52fe 100644 --- > a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -17,6 > +17,10 @@ > > #include > > +#ifndef tif_need_resched +#define tif_need_resched() > test_thread_flag(TIF_NEED_RESCHED) +#endif + #if > defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER) > extern void preempt_count_add(int val); extern void > preempt_count_sub(int val); diff --git > a/include/linux/thread_info.h b/include/linux/thread_info.h index > fddbe2023a5d..a629e4b23217 100644 --- > a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ > -118,8 +118,6 @@ static inline __deprecated void > set_need_resched(void) */ } > > -#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) - > #if defined TIF_RESTORE_SIGMASK && !defined > HAVE_SET_RESTORE_SIGMASK /* * An arch can define its own version of > set_restore_sigmask() to get the > - -- MfG/Sincerely Toralf Förster pgp finger print:1A37 6F99 4A9D 026F 13E2 4DCF C4EA CDDE 0076 E94E -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iF0EAREIAAYFAlNEW+EACgkQxOrN3gB26U5RkAD4ysUp9CrCajM7zXLsdWRLTZFi oX0lYgrKo/gCrcS9UwD/ZdaRPlP6vTKApfxQ7F48KTTA+tNcyTD4xSyCdwI8l0Q= =WeKZ -----END PGP SIGNATURE----- -- 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/