Re: [PATCH 0/6] writeback: moving expire targets for background/kupdate works

Wu Fengguang
2011-04-21T05:50:37Z

Hi Christoph,

On Thu, Apr 21, 2011 at 12:34:50PM +0800, Christoph Hellwig wrote:
> Hi Wu,
>
> if you're queueing up writeback changes can you look into splitting
> inode_wb_list_lock as it was done in earlier versions of the inode
> scalability patches? Especially if we don't get the I/O less
> balance_dirty_pages in ASAP it'll at least allows us to scale the
> busy waiting for the list manipulationes to one CPU per BDI.

Do you mean to split inode_wb_list_lock into struct bdi_writeback?
So as to improve at least the JBOD case now and hopefully benefit the
1-bdi case when switching to multiple bdi_writeback per bdi in future?

I've not touched any locking code before, but it looks like some dumb
code replacement. Let me try it :)

Thanks,
Fengguang