Re: [PATCH] panic: add TAINT_SOFTLOCKUP

From: Josh Hunt
Date: Mon Jun 23 2014 - 18:55:11 EST


On 06/23/2014 05:11 PM, Andrew Morton wrote:
On Tue, 3 Jun 2014 22:12:35 -0400 Josh Hunt <johunt@xxxxxxxxxx> wrote:

This taint flag will be set if the system has ever entered a softlockup
state. Similar to TAINT_WARN it is useful to know whether or not the system
has been in a softlockup state when debugging.

...

@@ -329,6 +329,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)

if (softlockup_panic)
panic("softlockup: hung tasks");
+ add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK);
__this_cpu_write(soft_watchdog_warn, true);
} else
__this_cpu_write(soft_watchdog_warn, false);

Would make more sense to have applied the taint *before* calling
panic()?

Andrew

Yep, that's a good call. Thanks. Do you want me to send a v2 or did you take care of it?

In addition to adding the softlockup taint flag, do you think it'd be reasonable to add another flag for page allocation failures? I think it'd be nice to be able to account for these conditions somehow without having to parse dmesg, etc. As with the softlockup flag, it's helpful to know if your system had encountered a page allocation failure at some point before the crash or whatever you're debugging.

Thanks
Josh
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