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 8E50A33F8A2; Fri, 17 Oct 2025 19:04:25 +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=1760727865; cv=none; b=rgN57Gl2M8gkYyBjFBkbkyagI0Nx3ufcukoA1BCpMs4ePdUUS3fYWZGtWMnOomJXdVC8rWssGeSWJ6oeA+QfPyHh+aTQtgq5CJmJ0cK9ZZPVNOaSvuYb9epHtMavyJqvpdPfi0GHt+/oWcioKaEZje3dap6NOcrqdtMJZkVfBto= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760727865; c=relaxed/simple; bh=Qt32d63SAE4stAqVZnBzVQMrPivjtQekm9eUkbEgEN4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CzbmcI0D/ptwDlHjVcH1gnFnhtXrUq+HI5aRM6htRjKBlbi6c/VJk3ANwuwQZq7Ma6aUJty7cyl6MvLPdLqSWK9cZr5t3sqXWL1Laq8KyIj7WlTEw2M9GRoWy6QeaYmh7rMju83VZCGEVCB0USxYi5BgW1FM/bsEw1KX87BsGmY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sbl55exf; 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="sbl55exf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E80F1C4CEE7; Fri, 17 Oct 2025 19:04:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760727865; bh=Qt32d63SAE4stAqVZnBzVQMrPivjtQekm9eUkbEgEN4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sbl55exf6cNSoTFxKXyWbkqtLizHLgPj30XTZKFQq2LeCr6NVK5f1I0sihyUUlFQR fhy0/lR94ikYDaSL+kBpRKKv6DCdd0uwoDJ146UHAeX9S8MWX7LgGq7zV1SeiOPoiE WvbaNEEbIdaemxNsDBeicPVLCGaYSHgYRYwQzUuloQxr5YaIedb8SrWMAgM3Ck196T ffEdF9cqwabagS6ueNZp4ume07sakJhrYNUx2VG+Sy6+aDP2qVdDTpJh8UUeLJ8zwp W6m8L6v64HrwwTLcYUttGJY0UOg9Op24Pw2s1H24lb0KqWAKFpinO8CTInNd68J0pA ttq9ha2UPvf5g== Date: Fri, 17 Oct 2025 09:04:23 -1000 From: Tejun Heo To: Andrea Righi Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Joel Fernandes , David Vernet , Changwoo Min , Shuah Khan , sched-ext@lists.linux.dev, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Luigi De Matteis Subject: Re: [PATCH 06/14] sched_ext: Add a DL server for sched_ext tasks Message-ID: References: <20251017093214.70029-1-arighi@nvidia.com> <20251017093214.70029-7-arighi@nvidia.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: On Fri, Oct 17, 2025 at 08:58:35PM +0200, Andrea Righi wrote: > On Fri, Oct 17, 2025 at 05:47:45AM -1000, Tejun Heo wrote: > > On Fri, Oct 17, 2025 at 11:25:53AM +0200, Andrea Righi wrote: > > > +static struct task_struct * > > > +ext_server_pick_task(struct sched_dl_entity *dl_se, struct rq_flags *rf) > > > +{ > > > + return pick_task_scx(dl_se->rq, rf); > > > +} > > > > I wonder whether we should tell pick_task_scx() to suppress the > > rq_modified_above() test in this case as a fair or RT task being enqueued > > has no reason to restart the picking process. While it will behave fine on > > retry, it's probably useful to be explicit here. > > Yeah, that's a valid point. Maybe we can add a new flag to rq->scx.flags? > Something like SCX_RQ_DL_SERVER_PICK? We can factor out the internals of pick_task_scx() into a separate function and add a flag there? Thanks. -- tejun