From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422723AbWJFXBW (ORCPT ); Fri, 6 Oct 2006 19:01:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422724AbWJFXBW (ORCPT ); Fri, 6 Oct 2006 19:01:22 -0400 Received: from out1.smtp.messagingengine.com ([66.111.4.25]:16075 "EHLO out1.smtp.messagingengine.com") by vger.kernel.org with ESMTP id S1422723AbWJFXBV (ORCPT ); Fri, 6 Oct 2006 19:01:21 -0400 X-Sasl-enc: PKwv7ArVa7OkV1K/0wqTO5zqyrEgx+P0dCNR0KSZu/2G 1160175681 Message-ID: <4526E0AC.9070105@imap.cc> Date: Sat, 07 Oct 2006 01:03:08 +0200 From: Tilman Schmidt Organization: me - organized?? User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; de-AT; rv:1.8.0.7) Gecko/20060910 SeaMonkey/1.0.5 Mnenhy/0.7.4.666 MIME-Version: 1.0 To: LKML CC: mingo@elte.hu Subject: v2.6.19-rc1 regression: printk missing klogd wakeup References: <72sfz-wa-1@gated-at.bofh.it> In-Reply-To: <72sfz-wa-1@gated-at.bofh.it> X-Enigmail-Version: 0.94.1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig988FC63E2C514997B72C7FE2" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig988FC63E2C514997B72C7FE2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Unsurprisingly, v2.6.19-rc1 still contains the problem I reported for v2.6.18-rc1 under the subject "Linux v2.6.18-rc1: printk delays" and later (unfortunately not before it made it into v2.6.18) tracked down through bisecting to [a0f1ccfd8d37457a6d8a9e01acebeefcdfcc306e] lockdep: do not recurse in pri= ntk Problem description: > While X is running, output from printk() appears in syslog (eg. > /var/log/messages) only after a key is pressed on the system keyboard, > even though it is visible with dmesg immediately. (from lkml message <450BF1CC.2070309@imap.cc> - see that message for further details) The problem did not exist in 2.6.17, so I think it qualifies as a regression. The following naive patch fixes the problem for me, without any apparent ill effects (ie. the menace of lockup never manifested itself): --- a/kernel/printk.c 2006-10-07 00:51:09.000000000 +0200 +++ b/kernel/printk.c 2006-10-07 00:51:41.000000000 +0200 @@ -826,8 +826,7 @@ void release_console_sem(void) * from within the scheduler code, then do not lock * up due to self-recursion: */ - if (!lockdep_internal()) - wake_up_interruptible(&log_wait); + wake_up_interruptible(&log_wait); } } EXPORT_SYMBOL(release_console_sem); But I guess for a proper fix the if() condition should rather be refined a bit than thrown out completely. --=20 Tilman Schmidt E-Mail: tilman@imap.cc Bonn, Germany Diese Nachricht besteht zu 100% aus wiederverwerteten Bits. Ungeoeffnet mindestens haltbar bis: (siehe Rueckseite) --------------enig988FC63E2C514997B72C7FE2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3rc1 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFFJuC5MdB4Whm86/kRAsSqAJsGRm+Y4fpBkZUAwApazRWK0poMVgCfchTb zhf2dpWtCVDke2MTymCPIUg= =B8Lx -----END PGP SIGNATURE----- --------------enig988FC63E2C514997B72C7FE2--