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Date: Fri, 28 Aug 2026 14:41:00 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: David Stevens <stevensd@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Thomas Gleixner <tglx@kernel.org>,
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	linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mm@kvack.org, linux-rt-devel@lists.linux.dev
Subject: Re: [RFC 06/10] Reclaim memory from blocked kernel stacks
Message-ID: <20260828124100.GO687043@noisy.programming.kicks-ass.net>
References: <20260827232948.2520558-1-stevensd@google.com>
 <20260827232948.2520558-7-stevensd@google.com>
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In-Reply-To: <20260827232948.2520558-7-stevensd@google.com>

On Thu, Aug 27, 2026 at 04:29:44PM -0700, David Stevens wrote:
> This feature does work on PREEMPT_RT, but is likely undesirable due to
> the extra uncertainty. The fact that alloc_pages_nolock_noprof() cannot
> be called from under the scheduler lock also makes repopulating stacks
> more expensive.

Aaah, so you knew it was hot garbage :-(

Please don't ever post anything like this again.