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 4FC79274B3A for ; Wed, 4 Feb 2026 10:44:49 +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=1770201890; cv=none; b=Th9IhwppdO7saqVVZpPFpJq6l0/9kj1szB/swdSlvizJOUDoU8IFwG8VhnfrLWIUzeDgpvaIpJfxwpmN6YLnytO8vNdTXvKOrteglU6uV1KaFl8t2tzl/zf9B2GMgMLphk8fsLcJhuYLIjttpYsREaaKiQLMkEQOyHELYXQRkXM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770201890; c=relaxed/simple; bh=eO3rAHzALelQABnpIKzFCBXGli70D0WUGHRBuqn0VBE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Lwck/VuCgP3qxY7QKwRGwRAI0kY+H/NM1aa21YN92Vi1DZeXQT93kVm1EsocYYmJHfLZDwN9sRnd0a47lOWAi6BwYnA9YXeF8cLrGhkeAypLpuAQI0WhfbWK5owaaXcpG6L6OxmktDMctaRT01NuKFCkeKZtvTJ3dGQe+FQJGD0= 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=dxBLKHw6; 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="dxBLKHw6" 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=1du2l2eAYxF285Kh+VEh92Z6kBNY7UIruLa1iKZyCno=; b=dxBLKHw6Smpzzcdu5eTmg25B2h JJuKHpebvPIbOUdu6hzaXNT0h8ml77SjqZiUOhbNyzWgE2DZ/KM2/YGbMRA+fsY1jPXaHi4D13WXY oMFHtqXn6o+SCNfXppq86FT1aPGtrALYb/uUoXCNDncJG5YAKd3fTr8cmJVQgDhAJxHUbUuaAxOnL ITgL5bXEbCaqB3WkKuSqBtWPe80wZKy0rNWjRE7Bk76y5jc2T1BSB0HMLnwoYtaRUdv5ca4dmntiV wdRogTzKtVAXIq/6Zn+6Jj6CjQ4YpS+WBb9/AjH+fh2eFmrYiCV3+nucLnl2CmE9zbafpGhQZ8Ft0 aBb3N4qw==; Received: from 2001-1c00-8d85-5700-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:5700:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vnaNA-00000000KxI-1aiD; Wed, 04 Feb 2026 10:44:36 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 33D6B300BD2; Wed, 04 Feb 2026 11:44:25 +0100 (CET) Date: Wed, 4 Feb 2026 11:44:25 +0100 From: Peter Zijlstra To: K Prateek Nayak Cc: mingo@kernel.org, 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, wangtao554@huawei.com, quzicheng@huawei.com, wuyun.abel@bytedance.com, dsmythies@telus.net Subject: Re: [PATCH 0/4] sched: Various reweight_entity() fixes Message-ID: <20260204104425.GD3016024@noisy.programming.kicks-ass.net> References: <20260130093439.803225718@infradead.org> <4c48fe59-8ff3-41fb-83cb-869409f6fbc6@amd.com> <20260203111134.GL1282955@noisy.programming.kicks-ass.net> <38ef3462-4c4e-4f40-8d63-84dd71cbd043@amd.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: <38ef3462-4c4e-4f40-8d63-84dd71cbd043@amd.com> On Tue, Feb 03, 2026 at 05:49:16PM +0530, K Prateek Nayak wrote: > > If any of the fields are !0, you tripped an overflow. > > Yup I see a few !0 values. Some inching closer to the BUG_ON() > > grep "shift.*: [^0]$" /sys/kernel/debug/sched/debug > .sum_shift : 4 > .sum_shift : 3 > .sum_shift : 5 > .sum_shift : 1 > .sum_shift : 2 > .sum_shift : 3 Whee. Clearly I have some work to do ;-) I'll go prod at this. Thanks!