On Thu, Jan 26, 2017 at 12:47:39PM -0500, Johannes Weiner wrote: > On Thu, Jan 26, 2017 at 09:57:45AM +0000, Mel Gorman wrote: > > On Mon, Jan 23, 2017 at 01:16:38PM -0500, Johannes Weiner wrote: > > > Memory pressure can put dirty pages at the end of the LRU without > > > anybody running into dirty limits. Don't start writing individual > > > pages from kswapd while the flushers might be asleep. > > > > > > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> > > > > I don't understand the motivation for checking the wb_reason name. Maybe > > it was easier to eyeball while reading ftraces. The comment about the > > flusher not doing its job could also be as simple as the writes took > > place and clean pages were reclaimed before dirty_expire was reached. > > Not impossible if there was a light writer combined with a heavy reader > > or a large number of anonymous faults. > > The name change was only because try_to_free_pages() wasn't the only > function doing this flusher wakeup anymore. Ah, ok. I was thinking of it in terms of "we are trying to free pages" and not the specific name of the direct reclaim function. > I associate that name with > direct reclaim rather than reclaim in general, so I figured this makes > more sense. No strong feelings either way, but I doubt this will break > anything in userspace. > Doubtful, maybe some tracing analysis scripts but they routinely have to adapt. > The comment on dirty expiration is a good point. Let's add this to the > list of reasons why reclaim might run into dirty data. Fixlet below. > Looks good. -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
