Re: pagefault in generic_file_buffered_write() causing deadlock

Chris Mason
2006-11-15T20:39:52Z

On Wed, Nov 15, 2006 at 11:29:57AM -0800, Andrew Morton wrote:
> Oh well. If it's a deadlock (this is not clear from your description) then
> please gather backtraces of all affected tasks.
>
> There is an ab/ba deadlock with journal_start() and lock_page(), iirc.
> Chris and I had a look at that a while back and collapsed in exhaustion -
> it isn't pretty.

This should be the page fault/journal lock inversion stuff Nick was
working on. His patchset had a pretty good description of the problems,
Badari can also dig through the novell/ltc bugzillas for vmmstress.
Should be LTC9358.

Hopefully Nick's patches will address all of this. sles9 had a partial
solution for the mmap deadlock, I think it was to dirty the inode at a
later time. For some reason, I thought this workload was passing in
later kernels...

-chris