On Tue, 08 Jan 2008 12:05:16 +0100 Mike Galbraith <[EMAIL PROTECTED]> wrote:
> > On Sun, 2008-01-06 at 12:29 -0800, Andrew Morton wrote: > > On Sun, 06 Jan 2008 19:01:10 +0100 Mike Galbraith <[EMAIL PROTECTED]> wrote: > > > > > > > > On Sun, 2008-01-06 at 10:42 +0100, Mike Galbraith wrote: > > > > FWIW, here's box having same seizure writing to /dev/pktcdvd/sr0. > > > > > > Ugh, horrid device IO ==> horrid VM AFIKT. I'll continue rummaging, but > > > I wonder, am I doing something _so_ stupid as to warrant zero response? > > > > > > > Copying linux-mm might have helped. Bad time of year, too. > > > > >From the traces it looks like all IO has stopped and everyone is waiting > > (directly or indirectly) for certain IO completions. Is that really true, > > or is IO still dribbling along? > > > > >From the kswapd0 trace it would appear that UDF is doing synchronous writes > > (udf_update_inode->sync_dirty_buffer) which perhaps is making things > > mightily slow. > > This is a pretty uninteresting thread except for the VM aspect, but > rather than leave it dangling, I'll laugh at my naivety and close. > > Seeks on DVD drives are apparently far FAR more horrible that I ever > imagined, so writing to a filesystem on a DVD+RW in effect constitutes > the stupid thing I was worried about above. Make an image, populate it, > write it instead... sure to be a truckload faster, and due to the VM > connection, much safer too. Oh well. > Well. From your earlier trace it appeared that something was causing the filesystem to perform synchronous inode writes - sync_dirty_buffer() was called. This will cause many more seeks than would occur if we were doing full delayed writing, with obvious throughput implications. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
