From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 94B51378D71 for ; Thu, 23 Apr 2026 10:06:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776938791; cv=none; b=omZVdZi9q4sD7iaLCvGVR/siZkP1HNXFN4o/zoAeQFZDdMFUJiwCQLMJrZ+hSRZ33z3SitTMeAk8lIZjhi1BNNAAYRH4EaQXsM2ok6maMi8Sienii5pC0588EDoHJcasdQythfO6WNeMkGOUC8FwGzSjrTwifeMBOIWyD9kycRI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776938791; c=relaxed/simple; bh=wCg3ppKt8D0iRsO11SW68vqC+dd9jVyva2LM6R84rI4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qg2SrNQXhMaPCU14f0D57aDLyT4nWFItJitQVx1EeNcYphWLhkkWDszGDWL4M6YRIRYMOe2AZbjUOxlFPHHHOlYKup4buxpNfTrf8Q0nlStwK+TDtW5zW+vVNflOW8NJsBHUp9NOP4EP1QHbW49J0toz2tRm/zvYXlHxL4/NBHc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=xDpYCx3M; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=OI8YhRII; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="xDpYCx3M"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="OI8YhRII" Date: Thu, 23 Apr 2026 12:06:27 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1776938788; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=KDuqNyrmgg5xRrb81O7Zm3JUXxPACJI5z4OhdpBkkGM=; b=xDpYCx3MsfY211KlrybTCXLrPBMxBQz6ZaauQKQ4q9lkOemswte0mrvaeskf5zzuvOkooe UZhnkD4WDbWW/z/q8/s9m4JOQ6a7stA8rx2rxAj+67ZtgBAMmrG0Ng9P5DW99ZjES4KRF5 BhHadhJ6KHl7/oMAmD2OwqwDqRHchnGeENqrFIMRiwTnxXpTQvHlyZU2PiMtylxEHnHUP3 DdnIdnl/eEHq7BzoVE+wCNYThuy9npt3icnkW+nSrzTwCuwIsMSttKCgtnRGX+cCJ2Rttn 4ceZEkaQY0Z1BDOemTzu9xOtKANQgqpmfoBhQRLWhlU6M8bF8dXEK79CbmgEhw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1776938788; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=KDuqNyrmgg5xRrb81O7Zm3JUXxPACJI5z4OhdpBkkGM=; b=OI8YhRIIwMgU1uUmnRqAZcWbfBo1WMy/avn7FUsndB7Ua95G8UDIkGIZ+sBnJehJUXXFpY KEGpQ8ioBR57mqAw== From: Sebastian Andrzej Siewior To: "Moritz KLAMMLER (FERCHAU)" Cc: Thomas Gleixner , Peter Zijlstra , "linux-rt-devel@lists.linux.dev" , "linux-kernel@vger.kernel.org" Subject: Re: AW: Possible PREEMPT_RT live-lock / priority-inversion between FUTEX_CMP_REQUEUE_PI and FUTEX_WAIT_REQUEUE_PI Message-ID: <20260423100627.O634mccg@linutronix.de> References: <20260323133034.vk87xPj9@linutronix.de> Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On 2026-03-23 16:12:24 [+0000], Moritz KLAMMLER (FERCHAU) wrote: > Thanks for your quick and helpful response, Sebastian. > > We have tried your patch and it indeed seems to solve the problem (using > the example program from my previous message as a test case). It also > certainly is more elegant than any of the other options we've considered > so far. Thank you very much. I'll report back if our system test > should find any unexpected regression in the following days. Ping. Sebastian