From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9D9613BB9F7 for ; Tue, 15 Sep 2026 13:13:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789478005; cv=none; b=s49lREqCX8F8MzVrqKFl46Cj4hPHeblUDJUm2EdbPck6TyqwHIU7bLIWL7549iIuUpEWe//Wf5+Beg65sG/tehYH89IVcLsqMr4HTKkpBEwSgxOH8p5juY5DgHyxhRxvejrQSLxGtccKoOvcBua2C6Uz3iWfnpHdROnopbbGHyI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789478005; c=relaxed/simple; bh=WK1m4iUpBi4TgQB3LFuoDYXYcCzFmj+S5FH1IYywWQo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pAkZ4bx2/9DBZrB/Qi2HJfbPOiJzRzEgIO4Ggrc9faaPQp9/Uux+/FhptVb0NGTtyXRPFF0mWyFWw4E0cLBwsE4eagAyZSq7kWc1uHgQuHyA/h6MgOP3Uyf2pvpZzvYo/YppG5GU+WeZzgtgrZaMNs21lLhC3MgS4narA2tjG7U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=pass smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=iy0Z7NLq; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="iy0Z7NLq" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=r/at6QZ3Yb69xOIrWqNlstKOMB33EJOfW7za0wXrTFw=; b=iy0Z7NLq1R37O9xL1QoHROM6Dy D15Z2geNen9RlC+BQ1dy3xm0iVZjf+xZZ3MnZMArhjowuvl+d1oDaSdZ/2zc33zmu1gkIioU7tRqq XnI50YiBNcZ9vFu7otf8UnBVJhnw2peUfUsxlvUljEM8VJCg20GWT7HVgYMa2jgmjVhTUr0AP5eKS bbUlE1yNHzBPRxrl18v/zMeHJk+ciVkollxTbL9v8xFDoZgZjoKIBLSywWnCuUGPEtdAKuTRMPXsG dH1kk25ywsI6sHzlc8INEz/R+8l6S+zJBPey1QVHkkb0Pn8k9Oz8DqGD4YpTn0f4h4t2fjfqGocjv tMLnWPTQ==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6SyK-0000000G9qo-0dWC; Tue, 15 Sep 2026 13:13:16 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 0EFC2300969; Tue, 15 Sep 2026 15:13:15 +0200 (CEST) Date: Tue, 15 Sep 2026 15:13:14 +0200 From: Peter Zijlstra To: David Laight Cc: Waiman Long , Ingo Molnar , Will Deacon , Boqun Feng , linux-kernel@vger.kernel.org, Linus Torvalds , Yafang Shao , Steven Rostedt Subject: Re: [PATCH v4 next 3/9] locking/osq_lock: Set prev_cpu=0 instead of locked=1 Message-ID: <20260915131314.GB2009045@noisy.programming.kicks-ass.net> References: <20260907084133.3696-1-david.laight.linux@gmail.com> <20260907084133.3696-4-david.laight.linux@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260907084133.3696-4-david.laight.linux@gmail.com> On Mon, Sep 07, 2026 at 09:41:27AM +0100, David Laight wrote: > + /* > + * If 'prev' tries to remove itself from the list before we write > + * a new value to prev->next it will spin in osq_wait_next(). > + */ This comment pertains to what? > + /* Invalidate prev_cpu matching osq_unlock() */ > + node->prev = 0; I'm confused, osq_unlock() does no such thing.