From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=gcLq=QF=vger.kernel.org=linux-kernel-owner@kernel.org>
Date: Tue, 29 Jan 2019 10:33:27 +0100
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: WARN_ON_ONCE(!new_owner) within wake_futex_pi() triggered
Message-ID: <20190129093327.GE28485@hirez.programming.kicks-ass.net>
References: <20181127081115.GB3625@osiris>
 <alpine.DEB.2.21.1811281526430.1532@nanos.tec.linutronix.de>
 <20181129112321.GB3449@osiris>
 <20190128134410.GA28485@hirez.programming.kicks-ass.net>
 <20190128135804.GB28878@hirez.programming.kicks-ass.net>
 <alpine.DEB.2.21.1901281650310.1582@nanos.tec.linutronix.de>
 <20190129090108.GA26906@osiris>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20190129090108.GA26906@osiris>
Sender: linux-kernel-owner@vger.kernel.org
List-Archive: <https://lore.kernel.org/lkml/>
List-Post: <mailto:linux-kernel@vger.kernel.org>
To: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>, Martin Schwidefsky <schwidefsky@de.ibm.com>, LKML <linux-kernel@vger.kernel.org>, linux-s390@vger.kernel.org, Stefan Liebler <stli@linux.ibm.com>, Sebastian Sewior <bigeasy@linutronix.de>
List-ID: <linux-s390.vger.kernel.org>

On Tue, Jan 29, 2019 at 10:01:08AM +0100, Heiko Carstens wrote:

> However now I see every now and then the following failure from the
> same test case:
> 
> tst-robustpi8: ../nptl/pthread_mutex_lock.c:425: __pthread_mutex_lock_full: Assertion `INTERNAL_SYSCALL_ERRNO (e, __err) != ESRCH || !robust' failed.
> 
> 		/* ESRCH can happen only for non-robust PI mutexes where
> 		   the owner of the lock died.	*/
> 		assert (INTERNAL_SYSCALL_ERRNO (e, __err) != ESRCH || !robust);
> 
> I just verified that this happened also without your patch, I just
> didn't see it since I started my tests with panic_on_warn=1 and the
> warning triggered always earlier.
> So, this seems to be something different.

*groan*... so while the other thing reproduced, I've not seen this
happen and I ran the test for hours.

I'll start it up again, see what happens..