From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 EED9E1F238A; Tue, 7 Jan 2025 14:50:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736261461; cv=none; b=B7/iNKM8KBrNOs1wKL+FC2AtWTydQ4PCD0UgIr9itqO12w8rqIhdEsjzOgng4H2n2sqURObZ+qMyuNQ2/NQ9nGM7/3muMfnN+5QfgcD1Tw8qKnZpxHwoxVK5P6g4EhBFjFj+amXTWFf7iOMLXctq44GhMOPgLjb9SnjYBkLGvtA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736261461; c=relaxed/simple; bh=qJzjlETX7LeS0DXplnQvRn5K3Ju/fkOM7qqiIKai7bc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qz+cVXtKo5Kq3YddOWRLPStNLYuBTvbw+nU3jHxS00flXRNjgLSJDHgbu5ThT1smZYD5+TyPZ9RN/mk7dMlFi7exA8Y+LoQad2PyOKjCbi3TtB6zthJYuQh9mcDOAhU37uX+YiLv28GpTL7L81hF7qgdDpkm7iz1qpHYohqz9PA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=bdGM3X40; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none 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="bdGM3X40" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=LqehdsfcI50oCVlJ1AA/1AKOJ10IfePPnL9tXWi/O3g=; b=bdGM3X40XB0h8JW7XTeJswGNaD zybEDZR7MkvrJkFU8igICuEsAOwuRktdavQJ4mduiZbxv+NeO+nNjtXkHmGMRdfmQ+fzFVgIhtGYc /UeuOayWO7z9M5d0cOAsPI887uzl4BRL7QneTIFLZExZswyg3rYE8ywDa6771AXMEJitBnwJyAJnu 3oTnkbmVUqts3Tyq06r2V/LWVHHcKA3vuTeBFnZ9rYz7aLuBQmE5wnURVGR4zjs4sPOTgK55Z4HYC pHG9ICFsB1bQn86CK8/F2MQRvkIBUIqxR6B1TPPdoMGNHHnTmmVLETaXO2QEfhkV93E+26CpPMpyU eUjB/eHw==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tVAuy-000000099wz-0NVd; Tue, 07 Jan 2025 14:50:52 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 31DD330057C; Tue, 7 Jan 2025 15:50:51 +0100 (CET) Date: Tue, 7 Jan 2025 15:50:51 +0100 From: Peter Zijlstra To: Kumar Kartikeya Dwivedi Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Barret Rhoden , Linus Torvalds , Waiman Long , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Eduard Zingerman , "Paul E. McKenney" , Tejun Heo , Josh Don , Dohyun Kim , kernel-team@meta.com Subject: Re: [PATCH bpf-next v1 07/22] rqspinlock: Add support for timeouts Message-ID: <20250107145051.GA23315@noisy.programming.kicks-ass.net> References: <20250107140004.2732830-1-memxor@gmail.com> <20250107140004.2732830-8-memxor@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: <20250107140004.2732830-8-memxor@gmail.com> On Tue, Jan 07, 2025 at 05:59:49AM -0800, Kumar Kartikeya Dwivedi wrote: > +struct rqspinlock_timeout { > + u64 timeout_end; > + u64 duration; > + u16 spin; > +}; > +#define RES_CHECK_TIMEOUT(ts, ret) \ > + ({ \ > + if (!((ts).spin++ & 0xffff)) \ Per the above spin is a u16, this mask is pointless. > + (ret) = check_timeout(&(ts)); \ > + (ret); \ > + })