From: Peter Zijlstra Subject: Re: [PATCH v4 6/7] sched: add function nr_running_cpu to expose number of tasks running on cpu Date: Mon, 14 Jul 2014 12:16:11 +0200 Message-ID: <20140714101611.GS9918@twins.programming.kicks-ass.net> References: <1405110784.2970.655.camel@schen9-DESK> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="2z7AKWNQ4hR/M4ga" Cc: Herbert Xu , "H. Peter Anvin" , "David S.Miller" , Ingo Molnar , Chandramouli Narayanan , Vinodh Gopal , James Guilford , Wajdi Feghali , Jussi Kivilinna , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org To: Tim Chen Return-path: Received: from bombadil.infradead.org ([198.137.202.9]:34391 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755316AbaGNKQ0 (ORCPT ); Mon, 14 Jul 2014 06:16:26 -0400 Content-Disposition: inline In-Reply-To: <1405110784.2970.655.camel@schen9-DESK> Sender: linux-crypto-owner@vger.kernel.org List-ID: --2z7AKWNQ4hR/M4ga Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jul 11, 2014 at 01:33:04PM -0700, Tim Chen wrote: > This function will help a thread decide if it wants to to do work > that can be delayed, to accumulate more tasks for more efficient > batch processing later. >=20 > However, if no other tasks are running on the cpu, it can take > advantgae of the available cpu cycles to complete the tasks > for immediate processing to minimize delay, otherwise it will yield. Ugh.. and ignore topology and everything else. Yet another scheduler on top of the scheduler. We have the padata muck, also only ever used by crypto. We have the workqueue nonsense, used all over the place And we have btrfs doing their own padata like muck. And I'm sure there's at least one more out there, just because. Why do we want yet another thing? I'm inclined to go NAK and get people to reduce the amount of async queueing and processing crap. --2z7AKWNQ4hR/M4ga Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTw63rAAoJEHZH4aRLwOS6jycP/iXJe7qpHcGSEWhGMxv6LdnH Bggi9SzB5e9sbcYm73ZxQAbZl1LZUTjH3cSv64nETbizo+xFSRmtQlhMEKukXOS2 uD/aBaEE0s5QjQ5GVEIat+EwDh1OZYpLS2YWzN65B3NVijGAnX1cgHaqgyjdEP00 aXdq1ySnjz6THZJhki8KNDqfkxeJXlA1UAW//wyLOue8mt9NbTJqh/Edy4WHU3dE jLBgn/Cclo5Txk3yxAr4otpbvc0PMBmQvwTspvExBXh8b+DUAh7LaZjYMFKVqYrl hD9zz8HrXe7wZlAxjIGoxVBFm7rDdl+9So8DK/Keu6SjEclNjK0WqM/PrKFs8G+R YdhmdrqNlZHlxuIvtG0ki9jzoGL45tm2XoOvIZH098EUzlhosL/BmM+E/FKWlYD3 lqhlAe26Ve8HsDCmpDwrYo2cWl/lPiHJV7wJ+MYNBl9eMrWzqJGyrRkHlwlLMPUN HxEureNThJ4U1DgSRYqiuFTDYms03JwB5Ysa1RVVdCb2yOZvog4iT7nHPCiZ85pQ NOKGqCtGBsbvvKjgCZJbNgIXhoPE1ZVmMUA/UZId5pSkuni9VGo61gb6zk7J4jLD lSWefTsfXM0ytW5wIqhI8D/XjYc86RYXU3yW2dGiowpSpzXVcxvwq23BJBtsmKc8 j7/6q38LtoGlzk52zybs =EROs -----END PGP SIGNATURE----- --2z7AKWNQ4hR/M4ga--