On Thu, Jun 06, 2013 at 01:37:42PM +1000, Dave Chinner wrote: > On Wed, Jun 05, 2013 at 04:08:15PM -0700, Andrew Morton wrote: > > On Mon, 3 Jun 2013 23:29:42 +0400 Glauber Costa <glommer@xxxxxxxxxx> wrote: > > > > > We already keep per-node LRU lists for objects being shrunk, but the > > > work that is deferred from one run to another is kept global. This > > > creates an impedance problem, where upon node pressure, work deferred > > > will accumulate and end up being flushed in other nodes. > > > > This changelog would be more useful if it had more specificity. Where > > do we keep these per-node LRU lists (names of variables?). > > In the per-node LRU lists the shrinker walks ;) > > > Where do we > > keep the global data? > > In the struct shrinker > > > In what function does this other-node flushing > > happen? > > Any shrinker that is run on a different node. > > > Generally so that readers can go and look at the data structures and > > functions which you're talking about. > > > > > In large machines, many nodes can accumulate at the same time, all > > > adding to the global counter. > > > > What global counter? > > shrinker->nr > > > > As we accumulate more and more, we start > > > to ask for the caches to flush even bigger numbers. > > > > Where does this happen? > > The shrinker scan loop ;) Answers which doesn't really tell you more than you already knew :/ To give you more background, Andrew, here's a pointer to the discussion where we analysed the problem that lead to this patch: http://marc.info/?l=linux-fsdevel&m=136852512724091&w=4 Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
