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From: Thomas Gleixner <tglx@linutronix.de>
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To: Oleg Nesterov <oleg@redhat.com>
Cc: John Stultz <jstultz@google.com>, Marco Elver <elver@google.com>, Peter
 Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>, "Eric W.
 Biederman" <ebiederm@xmission.com>, linux-kernel@vger.kernel.org,
 linux-kselftest@vger.kernel.org, Dmitry Vyukov <dvyukov@google.com>,
 kasan-dev@googlegroups.com, Edward Liaw <edliaw@google.com>, Carlos Llamas
 <cmllamas@google.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH v6 1/2] posix-timers: Prefer delivery of signals to the
 current thread
In-Reply-To: <20240404145408.GD7153@redhat.com>
References: <87sf02bgez.ffs@tglx> <87r0fmbe65.ffs@tglx>
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 <87frw2axv0.ffs@tglx> <20240404145408.GD7153@redhat.com>
Date: Thu, 04 Apr 2024 20:08:39 +0200
Message-ID: <87le5t9f14.ffs@tglx>
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On Thu, Apr 04 2024 at 16:54, Oleg Nesterov wrote:

> On 04/04, Thomas Gleixner wrote:
>>
>> IOW, we cannot test this reliably at all with the current approach.
>
> Agreed!
>
> So how about a REALLY SIMPLE test-case below?
>
> Lacks error checking, should be updated to match tools/testing/selftests.
>
> Without commit bcb7ee79029dca assert(sig_cnt > SIG_CNT) fails, the very
> 1st tick wakes the leader up.
>
> With that commit it doesn't fail.

Clever!