Re: [PATCH 0/4] writeback: tracing and wbc->nr_to_write fixes

Richard Kennedy
2010-04-20T12:00:53Z

On 20/04/10 03:41, Dave Chinner wrote:
> This series contains the initial writeback tracing patches from
> Jens, as well as the extensions I added to provide visibility into
> writeback control structures as the are used by the writeback code.
> The visibility given is sufficient to understand what is happening
> in the writeback path - what path is writing data, what path is
> blocking on congestion, etc, and to determine the differences in
> behaviour for different sync modes and calling contexts. This
> tracing really needs to be integrated into mainline so that anyone
> can improve the tracing as they use it to track down problems
> in our convoluted writeback paths.
>
> The remaining patches are fixes to problems that the new tracing
> highlighted.
>

Hi Dave,

Thanks for adding tracing to this, it will be really useful.

The fix to write_cache_pages looks really interesting, I'm going to test
it on my machine. Maybe it should be a separate patch to get more
visibility?

Ext4 also multiplies nr_to_write, so will that need fixing too?

regards
Richard