Re: [Bug 11388] New: 2.6.27-rc3 warns about MTRR range; only 3 of 16gb of memory is usable

Ingo Molnar
2008-08-23T10:43:36Z

* Yinghai Lu <yhlu.kernel@gmail.com> wrote:

> On Fri, Aug 22, 2008 at 5:22 PM, Joshua Hoblitt <j_kernel@hoblitt.com> wrote:
> > I've confirmed that the boards in these systems are Tyan Tempest
> > i5400PW (S5397)s. We've discovered a workload that will deadlock
> > the system under both 2.6.24.2 and -tip kernel with the mtrr masking
> > patch. The only thing unusual about this workload is that one of
> > the binaries in it constantly segvs... Is it possible that these
> > deadlocks (no kernel oops on console) are caused by MSR setup
> > wierdness or is it likely unrelated?
>
> could be other problem.
>
> cpu should be smarter enough to understand the missing bits in mask.
> at least amd cpu. remember that we didn't set mask bits to 40bits with
> opteron with LinuxBIOS, and everything still works well.

yeah. Is the deadlock debuggable? (does nmi_watchdog=1 produce anything
useful, or does the enabling of CONFIG_PROVE_LOCKING=y show anything
weird in the syslog during light, non-deadlocking use of this workload?)

Ingo