From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 9054E3DAAB6; Fri, 14 Aug 2026 20:56:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786740981; cv=none; b=lNnUxPQGtUCkyvrozHDthEZSkCeyUpvZ+yjlbhNzfhNQxBsr0KbGEzKlcQiZuESH6q7ifnv6bcN0eiaSFqatav0Jm2qUGVgdGcGkD0JjGFNkAn4t2pvT8TUiODTzZlw8BrMEF3H/kL1Zh/Ka4+JWNMQY30Q4drqbatqdOrtdOss= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786740981; c=relaxed/simple; bh=RLf+S4xWGgtGYLC4QaFImMLxfpR0WVLOSM+dtPHBNo4=; h=Date:Message-ID:From:To:Cc:In-Reply-To:References:Subject; b=Kw17wYLpXOve5FBTp5o09HBdeW1qJJH1vCtEGzdEj8BxIQw6yyoPeqQIiVc1GduIhHB0pO8j91ktQAW6jVDdkV6apf1qbqGzfWwIYq+s64Vyc7IbbthIuj771TMs4Fm4UWXCpMqj5+OEk68ygHyILXB1lH1OEQWJFGmqtrbWTMs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e+sZha+N; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e+sZha+N" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D4C51F000E9; Fri, 14 Aug 2026 20:56:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786740980; bh=RLf+S4xWGgtGYLC4QaFImMLxfpR0WVLOSM+dtPHBNo4=; h=Date:From:To:Cc:In-Reply-To:References:Subject; b=e+sZha+N7bxdxEVZo86Valxzhaz/7EvcbH2ba7UnxbsssKCdkIv3LX8wthlTNhiaq SLSleslx1FyakSDo+BVfZjPykku8qaVe9CTacP1ypLjWlAA/8EjimVhHNkzWESrtg1 johxofRPqFCqjAuZK6+QjsURDGjn2RbOVUOcBYUveM8zCZeMBXZIqF/bQUTRgSdHhT Wf9r5Tv3eBkmCi4CQSoFg5iguWg1x8x37Fdh0VmG9Ucs3FbnSwyuxgklYUXbzo9a36 +FcasCcfEMOemqMkgbILJ/ViyK79feLCIwtxzH0Mbz3KHp0aRhX5IIMR0WU6AZHTgt pNtbygssDaqeA== Date: Fri, 14 Aug 2026 10:56:19 -1000 Message-ID: <003d0a4f1c448113e18f9f5d61d00e99@kernel.org> From: Tejun Heo To: Tao Cui Cc: Tao Cui , void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, suzhidao@xiaomi.com, yphbchou0911@gmail.com, zhaomengmeng@kylinos.cn, sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org, bpf@vger.kernel.org In-Reply-To: <20260814144116.2767304-1-cui.tao@linux.dev> References: <20260814144116.2767304-1-cui.tao@linux.dev> Subject: Re: [PATCH] sched_ext/scx_flatcg: expire cached hweights on weight changes Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: On Fri, Aug 14, 2026 at 10:41:16PM +0800, Tao Cui wrote: > fcg_cgroup_set_weight() updates cgc->weight and the parent's > child_weight_sum but doesn't bump hweight_gen, so the hweights cached by > cgrp_refresh_hweight() stay stale until some task activation bumps the > generation. For cgroups whose tasks never go through a 0->n runnable > transition (e.g. persistently busy ones), a cpu.weight change never > propagates to scheduling at all. Applied to sched_ext/for-7.3. Thanks. -- tejun