On Thu, May 10, 2012 at 10:20 PM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: > On 05/10/2012 02:15 PM, Kay Sievers wrote: >> On Thu, May 10, 2012 at 10:13 PM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: >>> On 05/10/2012 02:09 PM, Stephen Warren wrote: >>>> On 05/10/2012 02:06 PM, Kay Sievers wrote: >>>>> On Thu, May 10, 2012 at 9:54 PM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: >>>>>> On 05/09/2012 12:31 PM, Stephen Warren wrote: >>>>>>> For me, next-20120508 prints nothing when booted, and I think also >>>>>>> hangs. To solve this, I reverted: >>>>>>> >>>>>>> 7ff9554 printk: convert byte-buffer to variable-length record buffer >>>>>>> >>>>>>> In order to build, I also had to revert: >>>>>>> >>>>>>> c4e00da driver-core: extend dev_printk() to pass structured data >>>>>>> >>>>>>> Note: I'm running on an ARM system using a serial console, with >>>>>>> earlyprintk enabled. >>>>>> >>>>>> This issue still occurs in next-20120510. >>>>>> >>>>>> I've tracked it down to the assignment of msg->ts_nsec near the end of >>>>>> log_store(). If I comment this out, everything works. The problem is the >>>>>> assignment, not the call to local_clock(): >>>>>> >>>>>> fails: >>>>>> msg->ts_nsec = local_clock(); >>>>>> fails: >>>>>> msg->ts_nsec = 0;//local_clock(); >>>>>> works: >>>>>> //msg->ts_nsec = local_clock(); >>>>> >>>>> Weird. >>>>> >>>>> What happens if you change it to: >>>>> cpu_clock(logbuf_cpu); >>>>> ? >>>>> >>>>> If it works, the timestamps look ok? >>>> >>>> I doubt that would work - after all, assigning 0 fails, but not >>>> performing the assignment at all works. But, I'll go try it... >>> >>> Calling cpu_clock() instead of local_clock() fails in the same way. >> >> Ok, didn't really see the assign to 0 you tried, sorry. :) >> >> And 'dmesg' works when you run the box with the line commented out? >> >> And 'cat /dev/kmsg'? > > Yes, both work and produce reasonable output. Really weird. I have zero ideas at what this could be. The messages in /dev/kmsg have seqnums, you see the 0 as the first? 5,0,0;Linux version 3.4.0-rc6+ ... 6,1,0;Command line: root=/dev/sda1 ... > "cat /dev/kmsg" does hang > at the end of the log until I CTRL-C it - is that expected? Yeah, 'cat' is a blocking read(), tools would use poll(). Kay -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
