[ltt-dev] [PATCH] Fix dirty page accounting in redirty_page_for_writepage()

[Christoph Lameter]

On Thu, 30 Apr 2009, Ingo Molnar wrote:

> nice. Do these all get called with irqs off, all the time?

In most cases yes. The VMstat patch includes an example were we may not
care too much about a event counter missing a beat once in a while for
platforms not supporting atomic per cpu ops. I know this affects IA64. The
cost of an atomic operations for an event counter update (which would have
avoided the potential of a concurrent update) was not justifiable.