[lkml]   [2001]   [Aug]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Write drop behind logic with used-once patch

On Thu, 16 Aug 2001, Daniel Phillips wrote:

> On August 16, 2001 09:43 am, Marcelo Tosatti wrote:
> > Hi Daniel,
> >
> > As far as I can see, the write drop behind logic with the used-once patch
> > is partly "gone" now: "check_used_once()" at generic_file_write() will set
> > all "write()n" pages to have age == PAGE_AGE_START (in case those pages
> > were not in cache before), which means they will be moved to the active
> > list later by page_launder(), effectively causing excessive pressure on
> > the current "active" pages since we have exponential page aging.
> >
> > I'm I overlooking some here or my thinking is correct ?
> The initial page create sets age=0 which serves as a "new" flag when the
> page is on the inactive list. When the page is actually touched the
> first time it transitions from age=0 to age=START, again the age is
> simply a state flag. When the page is touched the second time it's
> immediately activated, doing whatever activate does. I didn't touch
> activate.
> So any generic_read/write[1] page that gets used twice never gets to the
> end of the inactive queue, was that your question?


I'm afraid the new page_launder() logic will block tasks (kswapd mainly,
of course) on writeout of those "deactivated" pages (which are potentially

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 12:57    [W:0.042 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site