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Date: Fri, 24 May 2024 17:37:06 +0200
From: Andrea Parri <parri.andrea@gmail.com>
To: stern@rowland.harvard.edu, will@kernel.org, peterz@infradead.org,
	boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com,
	j.alglave@ucl.ac.uk, luc.maranget@inria.fr, paulmck@kernel.org,
	akiyks@gmail.com, dlustig@nvidia.com, joel@joelfernandes.org
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	hernan.poncedeleon@huaweicloud.com,
	jonas.oberhauser@huaweicloud.com
Subject: Re: [PATCH] tools/memory-model: Document herd7 (internal)
 representation
Message-ID: <ZlC0IkzpQdeGj+a3@andrea>
References: <20240524151356.236071-1-parri.andrea@gmail.com>
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In-Reply-To: <20240524151356.236071-1-parri.andrea@gmail.com>

> - While checking the information below using herd7, I've observed some
>   "strange" behavior with spin_is_locked() (perhaps, unsurprisingly...);
>   IAC, that's also excluded from this table/submission.

For completeness, the behavior in question:

$ cat T.litmus 
C T

{}

P0(spinlock_t *x)
{
	int r0;

	spin_lock(x);
	spin_unlock(x);
	r0 = spin_is_locked(x);
}

$ herd7 -conf linux-kernel.cfg T.litmus
Test T Required
States 0
Ok
Witnesses
Positive: 0 Negative: 0
Condition forall (true)
Observation T Never 0 0
Time T 0.00
Hash=6fa204e139ddddf2cb6fa963bad117c0

Haven't been using spin_is_locked for a while...  perhaps I'm doing
something wrong?  (IAC, will have a closer look next week...)

  Andrea