Messages in this thread |  | | Date | Tue, 17 Jun 2008 13:05:04 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH 1/2] memcg: res counter set limit |
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On Tue, 17 Jun 2008 09:10:38 +0530 Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
> KAMEZAWA Hiroyuki wrote: > > Helper function of res_counter for reducing usage in subsys(memcg). > > > > Changelog xxx -> v5. > > - new file. > > > > Background: > > In v3, I was asked to implement generic ones to res_counter. > > In v4. I was asked not to implement generic ones because memcg is only > > controller which can reduce usage by the kernel. Okay, maybe make sense. > > In this version, adds only necessary helpers to res_counter in > > not-invasive manner. > > > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > > > > --- > > include/linux/res_counter.h | 7 +++++++ > > kernel/res_counter.c | 24 ++++++++++++++++++++++++ > > 2 files changed, 31 insertions(+) > > > > Index: mm-2.6.26-rc5-mm3/include/linux/res_counter.h > > =================================================================== > > --- mm-2.6.26-rc5-mm3.orig/include/linux/res_counter.h > > +++ mm-2.6.26-rc5-mm3/include/linux/res_counter.h > > @@ -136,6 +136,12 @@ static inline bool res_counter_check_und > > return ret; > > } > > > > +/* > > + * set new limit to the val. if usage > val, returns -EBUSY. > > + * returns 0 at success. > > + */ > > +int res_counter_set_limit(struct res_counter *cnt, unsigned long long limit); > > + > > static inline void res_counter_reset_max(struct res_counter *cnt) > > { > > unsigned long flags; > > @@ -153,4 +159,5 @@ static inline void res_counter_reset_fai > > cnt->failcnt = 0; > > spin_unlock_irqrestore(&cnt->lock, flags); > > } > > + > > I don't understand this extra newline here > Sorry. I'll remove this ;)
Thanks, -Kame
> > #endif > > Index: mm-2.6.26-rc5-mm3/kernel/res_counter.c > > =================================================================== > > --- mm-2.6.26-rc5-mm3.orig/kernel/res_counter.c > > +++ mm-2.6.26-rc5-mm3/kernel/res_counter.c > > @@ -143,3 +143,27 @@ out_free: > > out: > > return ret; > > } > > + > > + > > +/** > > + * res_counter_set_limit - set limit of res_counter. > > + * @cnt: the res_counter > > + * @limit: the new limit > > + * > > + * Note that res_coutner_write() allows the same kind of operation. > > + * But this returns -EBUSY when new limit < usage. If you want strict control > > + * of limit, please use this. > > + */ > > +int res_counter_set_limit(struct res_counter *cnt, unsigned long long limit) > > +{ > > + unsigned long flags; > > + int ret = -EBUSY; > > + > > + spin_lock_irqsave(&cnt->lock, flags); > > + if (cnt->usage <= limit) { > > + cnt->limit = limit; > > + ret = 0; > > + } > > + spin_unlock_irqrestore(&cnt->lock, flags); > > + return ret; > > +} > > Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com> > > -- > Warm Regards, > Balbir Singh > Linux Technology Center > IBM, ISTL >
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