Re: [VM PATCH 2.6.6-rc3-bk5] Dirty balancing in the presence of mapped pages

[Nick Piggin <nickpiggin@yahoo.com.au>]

Andrew Morton wrote:
> Shantanu Goel <sgoel01@yahoo.com> wrote:
> 
>>Presently the kernel does not collection information
>>about the percentage of memory that processes have
>>dirtied via mmap until reclamation.  Nothing analogous
>>to balance_dirty_pages() is being done for mmap'ed
>>pages.  The attached patch adds collection of dirty
>>page information during kswapd() scans and initiation
>>of background writeback by waking up bdflush.
> 
> 
> And what were the effects of this patch?
> 

I havea modified patch from Nikita that does the
if (ptep_test_and_clear_dirty) set_page_dirty from
page_referenced, under the page_table_lock.

So it also picks up pages coming off the active list.

It doesn't do the wakeup_bdflush thing, but that sounds
like a good idea. What does wakeup_bdflush(-1) mean?