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 6B7AF2E7F02 for ; Thu, 6 Nov 2025 10:57:43 +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=1762426667; cv=none; b=knQlFdPWPrWP9+5xA+5HAcpguPWhkEvl4NaLzKygDZL6iFl/UMyw8l+UL4eZVe1w/OEV+mdDTh9SPQY8KKR/lNUC4koq+rXC2RkbqATigiAg664lvOngAbuo/ICAyrGsnaAscqUted7+sVwB+T4GL3Z8GC2kmYH/D/AimpUZbzA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762426667; c=relaxed/simple; bh=Pl/TCYsk7V6WSn1n4LeDxsgZRuuIxN4Rhgs2WV8q2j0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MePXJoub0I6zzA7bHxkH0IozDVSow3Ibt1v/sFeN2ROlxkj8Rxf549AFEOP3zW5f/zl3MdFgs32uViyS+Kp4lIlkdj8PzSyzW+g/LRUZxJOdNyiOtcWbFN+feRpblSXPWuZ1f3C+qNCB85x8ZiD1DC++24/Wn8OFEQWWkwJL5I8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=o3gmFzIt; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (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="o3gmFzIt" 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=b0m6PFCBA0tdiO6/JLX6FEs3Znbw0AJruUg5H+BCkQY=; b=o3gmFzItLW0iv/YXWFDoC1U4YV QRRavoElVArMXQTxR2z5TzTnIfrbS1sDvixU+GbqqQFcXLa4jJYHgHblAP1kV/JmuW86oPASGWIEl YAJZDzLr9MELf65iTPjI+mY30tzvilWjq4DgC0AHJ4p3HJWILWGqZtLTb/m1IxZLFewuctybSZ80z 1QuQEN8tf7N9l6lqbwaJbbhL837/uMauf5GQEz8UIddNyOeasYgLzVSbLLJH/0qChyaBrqER8frd8 RnbW4jzq4YQc+cyl7Rw2Xozi4VtXhV20rxozNhrP3DB7/i9Me8NlHh4NilWsPRe2gXFKO45GzH5gn Kbfs+/XA==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vGwoh-000000044QJ-1bEa; Thu, 06 Nov 2025 10:02:07 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 3F142300265; Thu, 06 Nov 2025 11:57:35 +0100 (CET) Date: Thu, 6 Nov 2025 11:57:35 +0100 From: Peter Zijlstra To: Fernand Sieber Cc: mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org, dwmw@amazon.co.uk, jschoenh@amazon.de, liuyuxua@amazon.com Subject: Re: [PATCH] sched: Proxy yields to donor tasks Message-ID: <20251106105735.GO3245006@noisy.programming.kicks-ass.net> References: <20251106104022.195157-1-sieberf@amazon.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: <20251106104022.195157-1-sieberf@amazon.com> On Thu, Nov 06, 2025 at 12:40:10PM +0200, Fernand Sieber wrote: > When executing a task in proxy context, handle yields as if they were > requested by the donor task. I'll modify this to say it matches the traditional PI semantics. > This avoids scenario like proxy task yielding, pick next task selecting the > same previous blocked donor, running the proxy task again, etc. > > Suggested-by: Peter Zijlstra > Signed-off-by: Fernand Sieber Thanks, I'll add: Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202510211205.1e0f5223-lkp@intel.com Also, for now proxy and ext are mutually exclusive, but yeah, might as convert that one now too. At some point someone will have to go through all that.