Re: [PATCH v14 072/138] mm/writeback: Add folio_account_cleaned()

[Matthew Wilcox]

On Thu, Aug 12, 2021 at 06:14:22PM +0200, Vlastimil Babka wrote:
> On 7/15/21 5:35 AM, Matthew Wilcox (Oracle) wrote:
> > Get the statistics right; compound pages were being accounted as a
> > single page.  This didn't matter before now as no filesystem which
> > supported compound pages did writeback.  Also move the declaration
> > to filemap.h since this is part of the page cache.  Add a wrapper for
> 
> Seems to be pagemap.h :)

Ugh, right.  filemap.c.  pagemap.h.  obviously.

> > +		wb_stat_mod(wb, WB_RECLAIMABLE, -nr);
> > +		task_io_account_cancelled_write(folio_size(folio));
> 
> In "mm/writeback: Add __folio_mark_dirty()" you used nr*PAGE_SIZE. Consistency?

We don't have any ;-)  I'll change that.  Some places we use <<
PAGE_SHIFT, some places we use * PAGE_SIZE ... either are better than
calling folio_size() unnecessarily.