On Tue, 16 Oct 2012 14:16:38 +0400 Glauber Costa <glommer@xxxxxxxxxxxxx> wrote: > From: Suleiman Souhlal <ssouhlal@xxxxxxxxxxx> > > We currently have a percpu stock cache scheme that charges one page at a > time from memcg->res, the user counter. When the kernel memory > controller comes into play, we'll need to charge more than that. > > This is because kernel memory allocations will also draw from the user > counter, and can be bigger than a single page, as it is the case with > the stack (usually 2 pages) or some higher order slabs. > > ... > > -/* > - * Try to consume stocked charge on this cpu. If success, one page is consumed > - * from local stock and true is returned. If the stock is 0 or charges from a > - * cgroup which is not current target, returns false. This stock will be > - * refilled. > +/** > + * consume_stock: Try to consume stocked charge on this cpu. > + * @memcg: memcg to consume from. > + * @nr_pages: how many pages to charge. > + * > + * The charges will only happen if @memcg matches the current cpu's memcg > + * stock, and at least @nr_pages are available in that stock. Failure to > + * service an allocation will refill the stock. > + * > + * returns true if succesfull, false otherwise. spello. > */ > -static bool consume_stock(struct mem_cgroup *memcg) > +static bool consume_stock(struct mem_cgroup *memcg, int nr_pages) I don't believe there is a case for nr_pages < 0 here? If not then I suggest that it would be clearer to use an unsigned type, like memcg_stock_pcp.stock. > > ... > -- 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>