Hello, On Tue, May 21, 2013 at 04:20:20PM +0100, Tom Cook wrote: > On Tue, May 21, 2013 at 12:16 PM, Sebastian Andrzej Siewior > <bigeasy@xxxxxxxxxxxxx> wrote: > > please CC the list. > > Sorry. > > > > > On 05/11/2013 06:43 PM, Tom Cook wrote: > [snip] > > > > Not known until you brought that up. I just booted x86 with kgdb=y and > > did "echo function > current_tracer" with no side effects. I don't have > > ARM at hand right now. Do you do anything kgdb related besides enabling > > it in the kernel? > > No. I've also tried compiling without kgdb and enabling tracers still > causes a crash (see below). > > Again, I'm far from expert here, but as near as I can tell, a fast > interrupt exception handler is causing a data abort exception. Do the > tracers use fast interrupts to wake up? Is there some tracer-related > memory that's getting swapped out? > > pi@raspberrypi:~/rt-tests$ sudo ./cyclictest -p95 -m -f -b 2000 > # /dev/cpu_dma_latency set to 0us > [ 199.186167] Bad mode in data abort handler detected > [ 199.186194] Internal error: Oops - bad mode: 0 [#1] PREEMPT ARM > [ 199.186246] Modules linked in: snd_bcm2835 snd_pcm snd_seq > snd_timer snd_seq_device snd snd_page_alloc > [ 199.186260] CPU: 0 Not tainted (3.6.11-rt31+ #1) > [ 199.186297] PC is at ring_buffer_lock_reserve+0x7c/0x144 > [ 199.186326] LR is at vfs_write+0x140/0x188 > [ 199.186341] pc : [<c009486c>] lr : [<c00efda4>] psr: 600001d1 > [ 199.186341] sp : da645ef8 ip : da645e28 fp : da645f6c > [ 199.186348] r10: 00000000 r9 : 00000000 r8 : 00000008 > [ 199.186357] r7 : 200001d1 r6 : c030226c r5 : c012cd64 r4 : c0732000 > [ 199.186366] r3 : 200001d1 r2 : 00000018 r1 : 00000000 r0 : db801420 > [ 199.186375] Flags: nZCv IRQs off FIQs off Mode FIQ_32 ISA ARM What are you using fiqs for? AFAIK they are not well supported in mainline Linux even. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
