From mboxrd@z Thu Jan 1 00:00:00 1970 From: Valdis.Kletnieks@vt.edu Subject: Re: suspend/resume PM criterion for application Date: Wed, 10 Sep 2014 13:59:44 -0400 Message-ID: <17893.1410371984@turing-police.cc.vt.edu> References: Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1410371984_2058P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Return-path: Received: from omr2.cc.vt.edu ([198.82.141.100]:57573 "EHLO omr2.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753059AbaIJSAy (ORCPT ); Wed, 10 Sep 2014 14:00:54 -0400 In-Reply-To: Your message of "Wed, 10 Sep 2014 20:26:48 +0300." Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Ran Shalit Cc: kernelnewbies , linux-pm@vger.kernel.org --==_Exmh_1410371984_2058P Content-Type: text/plain; charset=us-ascii On Wed, 10 Sep 2014 20:26:48 +0300, Ran Shalit said: > What is usually the criterion for PM (power management) suspending > that application shall use ? Is it according to minimum threshold for > cpu load (as indication for no process) ? That will be highly application dependent. Something that checks your email in the background may not care at all, as long as it gets network access every 5 minutes or so, and the entire system can power down for 4 minutes and 58 seconds as far as it cares. If it's doing media streaming, it may insist on having at least one CPU burst per screen refresh, and the CPU can go to sleep for the rest of the 1/30th of a second. > How usually it is performed, i.e. is it some periodic process, which > wakes up periodically to check criterion for cpu load ? If so, isn't > it problematic in PM terms, becuase it mean that the system is resumed > periodically (as a result of the the periodic timer's interrupt), and > all devices are resumed ? No, it can be done on a per-device basis. 'powertop' is a possibly useful tool for playing with this stuff that will let you look at power management on the fly. --==_Exmh_1410371984_2058P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Exmh version 2.5 07/13/2001 iQIVAwUBVBCRkAdmEQWDXROgAQJCxRAArav2gUoZCYwkxOI94SpakZBxWIPeZqPg zMHUO57h2Ir8M4gL1YCehUgQMAVHLfLObQrU+ScqcLoRQTrFWCKdhc97lohUBJgG IAYmpD/keY0zzznvkb1785qr8zIJaGQ7Qv79tPSmmDrp6dMsF9/ze7wVrprFIuqH mvobba7ACVro6lreBXDdAdhpoorcDJCnn8RVu99RUd8UOmoWO9XFtp4ZQHy3dd+M 2yBOyV51vicRnK9nvWN2pJ96FmcWxuCFBqkYIU0uWYu+VONT1hfHJDWHrZL6vLA2 28fj8+ODfIJMBoH4lMmCIPgbK562RlQDaz/8/tHq3c7edMn3KsS2iLo6i17aEwfk 19b2/ysotM1g5hyCkGLeCDHelBx63CAVTEmMQGjRmW16kRbLUGVL8x+NaVhTXGGw x7EBx/nyc+iNmCxiHKKynhkVBFr+jtY7jbwsWl4R0cxcksFOXNPVCiIausz8n+ZE w/G5oIh1HGIGOtoHVrqWifroP3As6y/6gWWM73wDl5BnUYBU1pECpw5VFON27Daz v8FqNKJ7a1OHxiwUSOiXPk9YAEulmKV/p5zxv4+ED7HiZH+kbvjpJ8JOX3l0STrc gnyGgxlS62ioODmlPsSmLfh53G6WB0PQ3w3658g21SNPcycIZWeBQ+TCYBll9NRH 7OePe6fVa6g= =0FcW -----END PGP SIGNATURE----- --==_Exmh_1410371984_2058P--