From mboxrd@z Thu Jan 1 00:00:00 1970 From: naresh kamboju Subject: Re: LTTng 0.193 fixes RT kernel support Date: Tue, 23 Feb 2010 16:59:03 +0530 Message-ID: References: <1266337450.24271.140.camel@gandalf.stny.rr.com> <20100216164744.GA25115@Krystal> <20100216170540.GA28039@Krystal> <20100217230854.GA25636@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, Steven Rostedt , ltt-dev@lists.casi.polymtl.ca, Thomas Gleixner , Ingo Molnar To: Mathieu Desnoyers Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: ltt-dev-bounces@lists.casi.polymtl.ca List-Id: linux-rt-users.vger.kernel.org On Mon, Feb 22, 2010 at 9:07 PM, naresh kamboju w= rote: > On Thu, Feb 18, 2010 at 4:38 AM, Mathieu Desnoyers > wrote: >> * naresh kamboju (naresh.kernel@gmail.com) wrote: >>> Hi, >>> >>> On Tue, Feb 16, 2010 at 10:35 PM, Mathieu Desnoyers wrote: >> [...] >>> > Oh, right. Thanks for the explanation. I'll look into moving LTTng to= a >>> > saner del_timer_sync() scheme to delete the timers. >>> >>> Could you give more info regarding, what kind of changes we can work on. >>> let me also work around on it. >>> >> >> I just released LTTng 0.193 for kernel 2.6.32.4 which includes patches >> fixing these odd per-cpu timer teardowns. > > I have downloaded LTTng 0.193 patches and viewed i can see below patches > > 1. lttng-transport-lockless-add-timer-on-works-with-del-timer-sync.patch > 2. omap-trace-clock-use-del-timer-sync.patch > 3. x86-trace-clock-use-mod-timer.patch > 4. trace-clock-32-to-64-use-del-timer-sync.patch FYI. I have ported LTTng 0.193 these four patches and able to resolve the issues on Uni-processor (UP) on ARM arch Thank you. A different bug is reported on SMP. BUG: using smp_processor_id() in preemptible [00000000] code: lttctl/754 caller is put_synthetic_tsc+0x7c/0xf8 Backtrace: [] (dump_backtrace+0x0/0x10c) from [] (dump_stack+0x18/= 0x1c) r7:c04c4994 r6:c008e24c r5:00000003 r4:ce0b6000 [] (dump_stack+0x0/0x1c) from [] (debug_smp_processor_id+0xc0/0xec) [] (debug_smp_processor_id+0x0/0xec) from [] (put_synthetic_tsc+0x7c/0xf8) r6:c04f82cc r5:c0023600 r4:00000003 [] (put_synthetic_tsc+0x0/0xf8) from [] (put_trace_clock+0x68/0x7c) r8:bece6eb9 r7:0000000b r6:ce0b7d2a r5:cc037600 r4:00000000 [] (put_trace_clock+0x0/0x7c) from [] (ltt_trace_destroy+0x40/0x94) [] (ltt_trace_destroy+0x0/0x94) from [] (destroy_trace_write+0xbc/0x140) r5:00000000 r4:0000000b [] (destroy_trace_write+0x0/0x140) from [] (vfs_write+0xb4/0x144) r7:0000000b r6:ce0b7f70 r5:bece6eb9 r4:ceae7860 [] (vfs_write+0x0/0x144) from [] (sys_write+0x48/0xf4) r7:0000000b r6:ceae7860 r5:00000000 r4:00000000 [] (sys_write+0x0/0xf4) from [] (__sys_trace_return+0x0/0x24) patch trace-clock-32-to-64-use-del-timer-sync.patch is causing above problem on SMP. with out this patch on SMP reported the previous bug as BUG: sleeping function called from invalid context at kernel/rtmutex.c:685 However, i'll investigate. Best regards, Naresh Kamboju >> Thanks, >> >> Mathieu >> >> -- >> Mathieu Desnoyers >> OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F =A0BA06 3F25 A8FE 3BAE= 9A68 >> >