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Date: Mon, 28 Oct 2024 11:24:08 +0100
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org,
	=?utf-8?B?QW5kcsOp?= Almeida <andrealmeid@igalia.com>,
	Darren Hart <dvhart@infradead.org>,
	Davidlohr Bueso <dave@stgolabs.net>, Ingo Molnar <mingo@redhat.com>,
	Juri Lelli <juri.lelli@redhat.com>,
	Valentin Schneider <vschneid@redhat.com>,
	Waiman Long <longman@redhat.com>
Subject: Re: [RFC PATCH 2/3] futex: Add basic infrastructure for local task
 local hash.
Message-ID: <20241028102408.GbFgnLMF@linutronix.de>
References: <20241026224306.982896-1-bigeasy@linutronix.de>
 <20241026224306.982896-3-bigeasy@linutronix.de>
 <20241028101633.GM9767@noisy.programming.kicks-ass.net>
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In-Reply-To: <20241028101633.GM9767@noisy.programming.kicks-ass.net>

On 2024-10-28 11:16:33 [+0100], Peter Zijlstra wrote:
> On Sun, Oct 27, 2024 at 12:34:51AM +0200, Sebastian Andrzej Siewior wrote:
> 
> > Introduce a task local hash map. The hashmap can be allocated via
> > 	prctl(PR_FUTEX_HASH, PR_FUTEX_HASH_ALLOCATE, 0)
> 
> Per process, per task is useless and will make things malfunction.
> 
> Things missing in this patch are CLONE_THREAD / CLONE_VM, and create
> must be absolutely forbidden once mm_users != 1.

I moved this to struct signal_struct and limited it for now to the
group leader.

Sebastian