Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932648AbaDHTvN (ORCPT ); Tue, 8 Apr 2014 15:51:13 -0400 Received: from smtp2.ngi.it ([88.149.128.113]:51884 "EHLO smtp2.ngi.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932233AbaDHTvL (ORCPT ); Tue, 8 Apr 2014 15:51:11 -0400 Message-ID: <53445343.1040907@katamail.com> Date: Tue, 08 Apr 2014 21:51:31 +0200 From: Michele Ballabio User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Peter Zijlstra , =?ISO-8859-1?Q?Toralf_F=F6rs?= =?ISO-8859-1?Q?ter?= CC: 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> <53444A9F.9060207@katamail.com> In-Reply-To: <53444A9F.9060207@katamail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/04/2014 21:14, Michele Ballabio wrote: > On 08/04/2014 14:21, 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 F?rster 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? >> >> --- >> 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 >> > > It works fine for me on top of v3.14. And on top of v3.13, too. Thanks. -- 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/