Re: OOPS (kswapd) in 2.4.5 and 2.4.6

Andrew Morton
2001-07-07T09:53:43Z

Henry wrote:
>
> >
> > I wonder why it only affects you. Is the drive which holds
> > your swap partition running in PIO mode? `hdparm' will tell
> > you. If it is, then that could easily cause the page to come
> > unlocked before brw_page() has finished touching the buffer
> > ring. Then all it takes is a parallel try_to_free_buffers
> > on the other CPU.
>
> Here's output from htparm:
>
> /dev/hda:
> multcount = 0 (off)
> I/O support = 0 (default 16-bit)
> unmaskirq = 0 (off)
> using_dma = 0 (off)
> keepsettings = 0 (off)
> nowerr = 0 (off)
> readonly = 0 (off)
> readahead = 8 (on)
> geometry = 2494/255/63, sectors = 40079088, start = 0
>
> Does this provide the info you need?

Bingo. PIO mode -> synchronous writes in submit_bh(). Thanks.

> I believe another chap responded to my post with a similar issue (also
> SMP machine).

No, his oops was a bad inode state while trying to
release unused NFS client inodes. Different bug :)

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