On Thu, 30 Apr 2015, Luis R. Rodriguez wrote: > > But for every param declared this way? I'm not sure we want that... > > I'm glad you bring this up, Christoph can you or anyone else can you provide > advise since you added __read_mostly ?
Well it should be reseved for data that is actually used frequently in hot paths. Initially we only moved variables into __read_mostly after we saw in performance traces that there was contention on an item because a neighboring variable was frequently written to. You want the __read_mostly data to be tighly packed. In the best case multiple frequently read variables for a hot path will be next to each other in order to reduce the number of cachelines needed to execute a critical path. That means being selective and aware of which variables actually benefit. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
