From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) (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 C63561A8412 for ; Tue, 27 May 2025 12:21:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.134.164.83 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748348486; cv=none; b=IR7tJ0818+H5JvZx2GuxULktGy5DMJXD95HWg7+Qqq8MBWJ9B/viUCAY9Od+TXYWV0TTCrdgOxb6WehDsRYnN37MeczZB7hP/1+t2GRjIFKbRZE96VKtuVwYkN1CeLdsixeVA+QlcK/dHuf+W//SLdg1qLYwopFBMQhrMTkPcL4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748348486; c=relaxed/simple; bh=njaKnl59JErNRojSBBz3f6BwDCSk7p8lFn5Smzd9CnU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gX3glEu7NDrZSaTnYBF2siYTEfkdSBPwEEgwLMCL1+aeKez9PQYmeHmyFCXBY0IRRiSxwX2vZqWiHvQHkkiEiythgQYbH+h7kM85e3KYeWAw8ZqBLWn3HzXf+WljnMpJKOQ17XxOplUnBLNagKWaqqZwjLftjhkIfA1SMv2HoMs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=inria.fr; spf=pass smtp.mailfrom=inria.fr; dkim=pass (1024-bit key) header.d=inria.fr header.i=@inria.fr header.b=F7ZMFDtT; arc=none smtp.client-ip=192.134.164.83 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=inria.fr Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=inria.fr Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=inria.fr header.i=@inria.fr header.b="F7ZMFDtT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=inria.fr; s=dc; h=date:from:to:cc:subject:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=f44EpMxIBKnEc9FiAbZt4Z0n8mgUWhfQ/1Iis7VbAh8=; b=F7ZMFDtT9UdSr404q+A4AqUHzzvrqJ7oQoZUUF2XIwlGC1/vDL8BlsZl 8MmyuFQreBj1oSqGF/eWBMuI+y72oadoZxceTXPLJJ7tqx1ge0sbJG1Ae oXc/aHstLNJyrs5z+QYSX85pl9dEg/W2URMZ5TIGV7w1n5wQiQr9enCKs k=; Authentication-Results: mail2-relais-roc.national.inria.fr; dkim=none (message not signed) header.i=none; spf=SoftFail smtp.mailfrom=jens.gustedt@inria.fr; dmarc=fail (p=none dis=none) d=inria.fr X-IronPort-AV: E=Sophos;i="6.15,318,1739833200"; d="scan'208";a="224138583" Received: from unknown (HELO inria.fr) ([130.79.192.217]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 May 2025 14:21:18 +0200 Date: Tue, 27 May 2025 14:21:18 +0200 From: =?UTF-8?B?SuKCkeKCmeKCmw==?= Gustedt To: Carlos O'Donell Cc: Alejandro Colomar , linux-man@vger.kernel.org Subject: Re: bug in futex.2, FUTEX_CMP_REQUEUE Message-ID: <20250527142118.05d15dd9@inria.fr> In-Reply-To: <8b77ea67-2662-411a-83c8-e0e23755244f@redhat.com> References: <20250527115303.3304206e@inria.fr> <8b77ea67-2662-411a-83c8-e0e23755244f@redhat.com> Organization: inria.fr X-Mailer: Claws Mail 4.2.0 (GTK 3.24.41; x86_64-pc-linux-gnu) X-Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwBAMAAAClLOS0AAAAAXNSR0IArs4c6QAAACRQTFRFERslNjAsLTE9Ok9wUk9TaUs8iWhSrYZkj42Rz6aD3sGZ Precedence: bulk X-Mailing-List: linux-man@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hello Carlos, On Tue, 27 May 2025 07:30:09 -0400, Carlos O'Donell wrote: > > This has several issues, the most severe beeing the word > > `FUTEX_WAIT`. > >=20 > > - How can an operation that only does wakes, ever be equivalent to a > > wait? =20 >=20 > My opinion is that the text is correct. >=20 > The operation can WAKE tasks. >=20 > The operation can also cause tasks to WAIT in a *different* queue. No, it can make *other* threads wait in a different queue. The `FUTEX_WAIT` call is to put the current thread on wait. So calling this equivalent is really far fetched. Thanks J=E2=82=91=E2=82=99=E2=82=9B --=20 :: ICube :::::::::::::::::::::::::::::: deputy director :: :: Universit=C3=A9 de Strasbourg :::::::::::::::::::::: ICPS :: :: INRIA antenne de Strasbourg :::::::::::::::::: Camus :: :: INRIA PIQ program Strasbourg :::::::::: piq.inria.fr :: :: :::::::::::::::::::::::::::::::::::: =E2=98=8E +33 368854536 :: :: https://icube-icps.unistra.fr/index.php/Jens_Gustedt ::