[techtalk] free_one_pmd: bad directory entry 00000020

Shawn Strout sstrout at nc.rr.com
Sat Jan 20 19:26:22 EST 2001

> -----Original Message-----
> From: techtalk-admin at linuxchix.org
> [mailto:techtalk-admin at linuxchix.org]On Behalf Of Jeff Dike
> Sent: Friday, January 19, 2001 2:03 PM
> To: Shawn Strout
> Cc: techtalk
> Subject: Re: [techtalk] free_one_pmd: bad directory entry 00000020
> > free_one_pmd: bad directory entry 00000020
> > Is this a kernel error and how severe is it? Should I worry?
> This looks like a NULL which has had a one-bit error in it.  If
> so, you have
> some flaky memory.
> It could crash your system if it happens in the right place.  The
> error above
> happened in a page table, which pretty serious.  If it had
> switched a bit in a
> non-zero pmd, you could have had some pretty serious data corruption.

Could you please be more specific? IANAKH (I Am Not A Kernel Hacker). What
is a NULL in this context and what kind of "directory" is it? I thought it
referred to the disk, but it sounds like you're saying it's a RAM problem.

It is happening frequently - sometimes several in a second and sometimes 10
minutes between. It is always in the same address, 00000020.

Do you have any suggestions on how to debug or correct it? Should I start
pulling RAM out of my machine and see if goes away?

Are you sure this is related to memory, or could there be some other cause?


More information about the Techtalk mailing list