From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Steinwender Subject: Problem with hwlat detector in smp_processor_id() Date: Thu, 09 Jul 2009 13:32:10 +0200 Message-ID: <4A55D53A.6040108@psysteme.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit To: linux-rt-users@vger.kernel.org Return-path: Received: from moutng.kundenserver.de ([212.227.126.187]:60484 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756545AbZGILcN (ORCPT ); Thu, 9 Jul 2009 07:32:13 -0400 Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hello everyone, I'm doing some testing here. When I'm trying the hardware latency test (hwlatdetect.py) I'm getting the following messages: hwlat_detector: version 1.0.0 BUG: using smp_processor_id() in preemptible [00000000] code: hwlatdetect/3755 caller is debug_sample_fread+0x138/0x1ea [hwlat_detector] Pid: 3755, comm: hwlatdetect Tainted: G N 2.6.29.5-M-jen80-rtpae-debug #1 Call Trace: [] ? printk+0x14/0x19 [] debug_smp_processor_id+0xb3/0xc8 [] debug_sample_fread+0x138/0x1ea [hwlat_detector] [] ? security_file_permission+0x14/0x16 [] ? rw_verify_area+0x8f/0xb1 [] ? debug_sample_fread+0x0/0x1ea [hwlat_detector] [] vfs_read+0x8e/0x138 [] sys_read+0x40/0x65 [] sysenter_do_call+0x12/0x2d The message is printed for every poll. Manually loading the hwlat module and reading "sample" produces the same message. I'm using a SuSE kernel with RT-Patches from j.eng (recompiled with hwlat Module). Version should roughly be 2.6.29.5-rt20, PAE is enabled. CPU is a dual core. The offending source could be: mutex_lock(&ring_buffer_mutex); e = ring_buffer_consume(ring_buffer, smp_processor_id(), NULL); I'm wondering, because the seems to run at least for some people. Can it be a problem with my kernel? Best regards, W. Steinwender