From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262191AbVAJK2p (ORCPT ); Mon, 10 Jan 2005 05:28:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262197AbVAJK2o (ORCPT ); Mon, 10 Jan 2005 05:28:44 -0500 Received: from linux01.gwdg.de ([134.76.13.21]:41686 "EHLO linux01.gwdg.de") by vger.kernel.org with ESMTP id S262191AbVAJK2l (ORCPT ); Mon, 10 Jan 2005 05:28:41 -0500 Date: Mon, 10 Jan 2005 11:28:38 +0100 (MET) From: Jan Engelhardt To: linux-kernel@vger.kernel.org Subject: keventd gives exceptional priority to usermode helpers Message-ID: MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="1283855629-689907754-1105352918=:11128" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --1283855629-689907754-1105352918=:11128 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi, on SUSE 9.2, we experienced that plugging in an USB stick slows the system down considerably. In the end, I tracked (one half of the problem) down to kernelspace, where keventd starts the /sbin/hotplug usermode helper with priority -20. This is bad because hotplug, udev or the programs that ship with the whole hotplug subsystem (possibly including SUSE's own scripts) require some CPU -- and with nice -20 get it definitely. keventd itself should stay at nice level -20, since it also spawns kreiserfsd, just to name one. So the (attached) patch reprioritizes *user*mode helpers/tasks back to nice 0. Signed-off-by: Jan Engelhardt Jan Engelhardt -- ENOSPC --1283855629-689907754-1105352918=:11128 Content-Type: TEXT/PLAIN; charset=US-ASCII; name="renice_keventd_usermode.diff" Content-Transfer-Encoding: BASE64 Content-ID: Content-Description: Content-Disposition: attachment; filename="renice_keventd_usermode.diff" Iz09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQ0KIyBMaW51eCAy LjYtSFggTU9ESUZJQ0FUSU9ODQojICAgQ29weXJpZ2h0IChDKSBKYW4gRW5n ZWxoYXJkdCA8amVuZ2VsaCBbYXRdIGxpbnV4MDEgZ3dkZyBkZT4sIDIwMDQN CiMgICAtLSBMaWNlbnNlIHJlc3RyaWN0aW9ucyBhcHBseSAoR1BMMikNCiMg ICAtLSBGb3IgZGV0YWlscyBzZWUgZG9jL0dQTDIudHh0Lg0KIyAgIGh0dHA6 Ly9saW51eDAxLm9yZzoyMjIyL3Byb2ctaHh0b29scy5waHANCiM9PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT0NCiMgRmlsZTogIHV0ZjhmaXgu ZGlmZg0KIyBDbGFzczoNCiMNCiMgLSB1ZGV2IGFuZCBmcmllbmRzIG5lZWQg YSBmYWlyIGFtb3VudCBvZiBDUFUsIGFuZCByZWFsbHkgYnJpbmcgZG93biB0 aGUNCiMgICBzeXN0ZW0gd2hlbiB0aGV5IHJ1biAtLSB1c3VhbGx5IGluIG5p Y2UgLTIwDQojICAgRml4IGl0IGluIHRoYXQgdXNlcm1vZGUgaGVscGVycyBh bHdheXMgZ2V0IG5pY2UgMCBieSBkZWZhdWx0DQojDQojLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tDQpkaWZmIC1kcHUgdXNyX0Evc3JjL2tv dGQvbGludXgtMi42LjgtMjAwNDEyMDQwMzAyMDAva2VybmVsL2ttb2QuYyB1 c3JfQi9zcmMva290ZC9saW51eC0yLjYuOC0yMDA0MTIwNDAzMDIwMC9rZXJu ZWwva21vZC5jDQotLS0gdXNyX0Evc3JjL2tvdGQvbGludXgtMi42LjgtMjAw NDEyMDQwMzAyMDAva2VybmVsL2ttb2QuYwkyMDA0LTEyLTA2IDE0OjI4OjQ0 LjAwMDAwMDAwMCArMDEwMA0KKysrIHVzcl9CL3NyYy9rb3RkL2xpbnV4LTIu Ni44LTIwMDQxMjA0MDMwMjAwL2tlcm5lbC9rbW9kLmMJMjAwNS0wMS0wNiAx MTo0NDowNC4xMzA2MDAwMDAgKzAxMDANCkBAIC0xNjUsNiArMTY1LDcgQEAg c3RhdGljIGludCBfX19fY2FsbF91c2VybW9kZWhlbHBlcih2b2lkIA0KIA0K IAkvKiBXZSBjYW4gcnVuIGFueXdoZXJlLCB1bmxpa2Ugb3VyIHBhcmVudCBr ZXZlbnRkKCkuICovDQogCXNldF9jcHVzX2FsbG93ZWQoY3VycmVudCwgQ1BV X01BU0tfQUxMKTsNCisgICAgICAgIHNldF91c2VyX25pY2UoY3VycmVudCwg MCk7DQogDQogCXJldHZhbCA9IC1FUEVSTTsNCiAJaWYgKGN1cnJlbnQtPmZz LT5yb290KQ0K --1283855629-689907754-1105352918=:11128--