From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759458AbZC0Q24 (ORCPT ); Fri, 27 Mar 2009 12:28:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757204AbZC0Q2q (ORCPT ); Fri, 27 Mar 2009 12:28:46 -0400 Received: from mail.phnxsoft.com ([195.227.45.4]:4319 "EHLO posthamster.phnxsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754371AbZC0Q2q (ORCPT ); Fri, 27 Mar 2009 12:28:46 -0400 Message-ID: <49CCFEBA.6060009@imap.cc> Date: Fri, 27 Mar 2009 18:28:42 +0200 From: Tilman Schmidt User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; de-AT; rv:1.8.1.19) Gecko/20081204 SeaMonkey/1.1.14 Mnenhy/0.7.6.0 MIME-Version: 1.0 To: Linux Kernel Mailing List Subject: Help: tasklet blocked for >8msec X-Enigmail-Version: 0.95.7 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig2B53C522A24EF27745B40F78" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig2B53C522A24EF27745B40F78 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable A user of the Gigaset base driver (drivers/isdn/gigaset/bas-gigaset.c) reports his connection being dropped exactly every 30 seconds. Analysis of his dmesg indicates that when the error occurs, both the tasklets read_iso_tasklet and write_iso_tasklet handling the B channel data stream (125 USB isochronous packets per second in each direction) are at the same time not executed for an entire inter-packet interval, ie. 8 msecs. The machine in question, an Intel Core2 Duo E8600 with 4 GB RAM and SATA hard disks, should really be fast enough. CPU load is negligible. I have asked the user to recompile the kernel with CONFIG_PREEMPT=3Dy and to replace the calls to schedule_tasklet() for the two tasklets by schedule_hi_tasklet(). That had no noticeable effect on the problem. I would be grateful for any hint on what could be the cause for that blockage and how to prevent it. aTdHvAaNnKcSe Tilman --=20 Tilman Schmidt E-Mail: tilman@imap.cc Bonn, Germany Diese Nachricht besteht zu 100% aus wiederverwerteten Bits. Unge=F6ffnet mindestens haltbar bis: (siehe R=FCckseite) --------------enig2B53C522A24EF27745B40F78 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.4 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFJzP66Q3+did9BuFsRAni6AJwM+JV2MfPhD60ptpqE+8MbhhxLEACfaLMT QhkhBUlOaLKnWPmVm76tBoM= =3Kj4 -----END PGP SIGNATURE----- --------------enig2B53C522A24EF27745B40F78--