From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EDE4B2F7EE0 for ; Fri, 15 May 2026 17:17:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778865466; cv=none; b=smbzqzR2RzRigOHOVRwKRBr0eup4LBIIvQNPc/b5Qq1TpyX62LhPdBBm0vQiqT60dmQ4mgb6FsRcmWLHjPI+uMOdD/nLWy9iuMf7dsAxrmwQXkIi970MV7jUD8eQgAfjLR8aHCygNHCkSt0uzOziliQ/jIfManDV5Ry3j2PsAuo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778865466; c=relaxed/simple; bh=NhZb7829pCErlPXjf1DE5rTycr4+/IWqgM3BK733nGI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CT7rA9fP4MFytzO03Kt9cyNiWE6mNdMao3l9SNNd5h/LYIWcTY20jfdAjPDO1EY2eb7jSuN5u5JzQbuvAavOo9CaHZ8qS3x6IXnlPf1E4pF+V77/1mnfXCVBBXnquca3sGiXQXeHTZup07t/9cZB2haOMps2boPkxWrss9eY9FI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R12Bq5QS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="R12Bq5QS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B54CBC2BCB3; Fri, 15 May 2026 17:17:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778865465; bh=NhZb7829pCErlPXjf1DE5rTycr4+/IWqgM3BK733nGI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R12Bq5QSST4JA8u7PmJg3NviBwhXhM+FaY9gE6k7WoMalTeP6JAi+IKFWGTZlBE4M zzh/eM6HqGi+eVvWA65gCMbEovnNrcM0lU6TxsMog5D4YV0sFQ6B4UgdM49gznsqzy j1Upsk7DEECuzGT+BhrHqHY4gscVAEaqTNCSUERoP8ikCk+p60bGgEXZX+4nY27GS7 TtgoKFrbnyemuEWmPdgaz/ridxv9KYHzt25HZsI2xrhrJiyY/YABvPrcTlNcAtBN+A RyuwIAVdNf8eryt8+/Y24KOArc/4vifPxmkI30blSojaHrzO57oHb5r/OpIBw2LOm8 8p0fjBvnZr71g== Date: Fri, 15 May 2026 07:17:44 -1000 From: Tejun Heo To: Steven Rostedt Cc: LKML , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Kyle McMartin Subject: Re: [PATCH v2] sched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT Message-ID: References: <20260515103740.25ccbed8@gandalf.local.home> 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: <20260515103740.25ccbed8@gandalf.local.home> On Fri, May 15, 2026 at 10:37:40AM -0400, Steven Rostedt wrote: ... > A live lock occurred on a workload that was doing heavy networking traffic > on a large machine where the softirqs would run 500us out of 750us. And it > would also be waking up RT tasks, causing the RT pull logic to be > constantly executed. nit: 500/750us is the synthetic repro. The actual case is 30-40% cpu util, so substantially lower. > Reported-by: Tejun Heo > Closes: https://lore.kernel.org/all/20260506235716.2530720-1-tj@kernel.org/ > Signed-off-by: Steven Rostedt Tested-by: Tejun Heo Thanks. -- tejun