On Wed, 25 Mar 2015 15:10:44 +0100 Florian Echtler <floe@xxxxxxxxxxxxxx> wrote: > Hello Dmitry, > > On 25.03.2015 14:23, Dmitry Torokhov wrote: > > On March 24, 2015 11:52:54 PM PDT, Florian Echtler <floe@xxxxxxxxxxxxxx> wrote: > >> Currently, I'm setting the interval for input_polldev to 10 ms. > >> However, with video data being retrieved at the same time, it's quite > >> possible that one iteration of poll() will take longer than that. Could > >> this ultimately be the reason? What happens if a new poll() call is > >> scheduled before the previous one completes? > > > > This can't happen as we schedule the next poll only after current one completes. > > > Thanks - any other suggestions how to debug such a complete freeze? I > have the following options enabled in my kernel config: > > CONFIG_LOCKUP_DETECTOR=y > CONFIG_HARDLOCKUP_DETECTOR=y > CONFIG_DETECT_HUNG_TASK=y > CONFIG_EARLY_PRINTK=y > CONFIG_EARLY_PRINTK_DBGP=y > CONFIG_EARLY_PRINTK_EFI=y > > Unfortunately, even after the system is frozen for several minutes, I > never get to see a panic message. Maybe it's there on the console > somewhere, but the screen never switches away from X (and as mentioned > earlier, I think this bug can only be triggered from within X). Network > also freezes, so I don't think netconsole will help? > PSTORE + some EFI/ACPI mechanism, maybe? http://lwn.net/Articles/434821/ However I have never tried that myself and I don't know if all the needed bits are in linux already. JFTR, on some embedded system I worked on in the past the RAM content was preserved across resets and, after a crash, we used to dump the RAM from a second stage bootloader (i.e. before lading another linux instance) and then scrape the dump to look for the kernel messages, but AFAIK this is not going to be reliable —or even possible— on a more complex system. Ciao, Antonio -- Antonio Ospite http://ao2.it A: Because it messes up the order in which people normally read text. See http://en.wikipedia.org/wiki/Posting_style Q: Why is top-posting such a bad thing? -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
