Messages in this thread | | | Date | Fri, 21 May 2010 18:00:14 +0200 | From | Jan Kara <> | Subject | Re: RFC: dirty_ratio back to 40% |
| |
On Fri 21-05-10 10:11:59, KOSAKI Motohiro wrote: > > > So, I'd prefer to restore the default rather than both Redhat and SUSE apply exactly > > > same distro specific patch. because we can easily imazine other users will face the same > > > issue in the future. > > > > On desktop systems the low dirty limits help maintain interactive feel. > > Users expect applications that are saving data to be slow. They do not > > like it when every application in the system randomly comes to a halt > > because of one program stuffing data up to the dirty limit. > > really? > Do you mean our per-task dirty limit wouldn't works? > > If so, I think we need fix it. IOW sane per-task dirty limitation seems > independent issue from per-system dirty limit. Well, I don't know about any per-task dirty limits. What function implements them? Any application that dirties a single page can be caught and forced to call balance_dirty_pages() and do writeback. But generally what we observe on a desktop with lots of dirty memory is that application needs to allocate memory (either private one or for page cache) and that triggers direct reclaim so the allocation takes a long time to finish and thus the application is sluggish...
Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR
| |