lkml.org 
[lkml]   [2011]   [Aug]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: powertop "pread cpu0 0xe8 : Bad file descriptor" fixed by CONFIG_MSR
From
On Sun, Aug 7, 2011 at 6:52 AM, Andy Isaacson <adi@hexapodia.org> wrote:
> I hadn't seen this issue discussed on the list, and I don't know of a
> powertop mailing list, so here's what stymied my use of powertop until I
> straced it.
>
> With CONFIG_MSR=n, powertop "1.97-2" (from Debian unstable) on 3.0.1
> (and presumably many other recent kernels) exits at startup with:
>
> pread cpu0 0xe8 : Bad file descriptor
>
> strace shows:
>
> open("/dev/cpu/0/msr", O_RDONLY) = -1 ENOENT (No such file or directory)
> pread(4294967295, 0x7fff4c8347c8, 8, 232) = -1 EBADF (Bad file descriptor)
>

Seems powertop forgot to check the return value of that open().
This is a bug of powertop, not kernel.


\
 
 \ /
  Last update: 2011-08-08 11:11    [W:0.051 / U:0.340 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site