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From: peterz@infradead.org
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Joerg Vehlow <lkml@jv-coder.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Huang Ying <ying.huang@intel.com>,
	linux-kernel@vger.kernel.org,
	Joerg Vehlow <joerg.vehlow@aox-tech.de>,
	dave@stgolabs.net
Subject: Re: [BUG RT] dump-capture kernel not executed for panic in interrupt context
Date: Sat, 22 Aug 2020 14:32:52 +0200	[thread overview]
Message-ID: <20200822123252.GQ1362448@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200821170334.73b52fdd@oasis.local.home>

On Fri, Aug 21, 2020 at 05:03:34PM -0400, Steven Rostedt wrote:

> > Sigh.  Is it too hard to make mutex_trylock() usable from interrupt
> > context?
> 
> 
> That's a question for Thomas and Peter Z.

You should really know that too, the TL;DR answer is it's fundamentally
buggered, can't work.

The problem is that RT relies on being able to PI boost the mutex owner.

ISTR we had a thread about all this last year or so, let me see if I can
find that.

Here goes:

  https://lkml.kernel.org/r/20191218135047.GS2844@hirez.programming.kicks-ass.net

Kexec even gets mentioned:

  https://lkml.kernel.org/r/20191219090535.GV2844@hirez.programming.kicks-ass.net



  reply	other threads:[~2020-08-22 12:33 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-28 11:41 [BUG RT] dump-capture kernel not executed for panic in interrupt context Joerg Vehlow
2020-05-28 12:46 ` Steven Rostedt
2020-07-22  4:30   ` Joerg Vehlow
2020-07-22 20:51     ` Steven Rostedt
2020-07-27 23:36     ` Andrew Morton
2020-08-21 10:25       ` Joerg Vehlow
2020-08-21 15:08         ` Steven Rostedt
2020-08-21 20:47           ` Andrew Morton
2020-08-21 21:03             ` Steven Rostedt
2020-08-22 12:32               ` peterz [this message]
2020-08-22 23:49                 ` Steven Rostedt
2020-09-07 11:41                   ` peterz
2020-09-07 12:49                     ` Valentin Schneider
2020-09-14 19:00                     ` Steven Rostedt
2020-09-07 10:51               ` Joerg Vehlow
2020-09-07 11:46                 ` peterz
2020-09-07 12:03                   ` Joerg Vehlow
2020-09-07 16:23                     ` peterz
2020-09-08  5:48                       ` Joerg Vehlow
2020-09-09  5:46                         ` Joerg Vehlow
2020-09-11 22:48                           ` Eric W. Biederman
2020-09-14  6:03                             ` Joerg Vehlow
2020-09-14 16:46                               ` Eric W. Biederman
2020-09-14 16:46                                 ` Eric W. Biederman

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