Re: [RFC] changes to buffer.c (was Test12 ll_rw_block error)

Marcelo Tosatti
2000-12-22T03:02:14Z

On Thu, 21 Dec 2000, Andreas Dilger wrote:

> Marcelo Tosatti writes:
> > It seems your code has a problem with bh flush time.
> >
> > In flush_dirty_buffers(), a buffer may (if being called from kupdate) only
> > be written in case its old enough. (bh->b_flushtime)
> >
> > If the flush happens for an anonymous buffer, you'll end up writing all
> > buffers which are sitting on the same page (with block_write_anon_page),
> > but these other buffers are not necessarily old enough to be flushed.
>
> This isn't really a "problem" however. The page is the _maximum_ age of
> the buffer before it needs to be written. If we can efficiently write it
> out with another buffer

> (essentially for free if they are on the same spot on disk)

Are you sure this is true for buffer pages in most cases?