Messages in this thread | | | Date | Wed, 12 Nov 2008 13:22:19 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [RFC][PATCH 4/6] memcg: swap cgroup for remembering account |
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On Wed, 12 Nov 2008 13:17:01 +0900 Daisuke Nishimura <d-nishimura@mtf.biglobe.ne.jp> wrote:
> > +/** > > + * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry > > + * @ent: swap entry to be looked up. > > + * > > + * Returns pointer to mem_cgroup at success. NULL at failure. > > + */ > > +struct mem_cgroup *lookup_swap_cgroup(swp_entry_t ent) > > +{ > > + int type = swp_type(ent); > > + unsigned long flags; > > + unsigned long offset = swp_offset(ent); > > + unsigned long idx = offset / SC_PER_PAGE; > > + unsigned long pos = offset & SC_POS_MASK; > > + struct swap_cgroup_ctrl *ctrl; > > + struct page *mappage; > > + struct swap_cgroup *sc; > > + struct mem_cgroup *ret; > > + > > + if (!do_swap_account) > > + return NULL; > > + > > + ctrl = &swap_cgroup_ctrl[type]; > > + > > + mappage = ctrl->map[idx]; > > + > > + spin_lock_irqsave(&ctrl->lock, flags); > > + sc = kmap_atomic(mappage, KM_USER0); > > + sc += pos; > > + ret = sc->val; > > + kunmap_atomic(mapppage, KM_USER0); > s/mapppage/mappage > > I don't know why I didn't notice this while testing previous version. > Ah...kmap_atomic() doesn't check its argument if HIGHMEM=n. and mapppage disappears by macro.
I'm now preparing x86-32 test enviroment before goint further.
Thanks, -Kame
> > Thanks, > Daisuke Nishimura. > > > + spin_unlock_irqrestore(&ctrl->lock, flags); > > + return ret; > > +} > > + >
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