Messages in this thread | | | Date | Tue, 4 Oct 2011 03:17:51 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH 01/10] cgroups: Add res_counter_write_u64() API |
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On Mon, Oct 03, 2011 at 09:07:03PM +0200, Frederic Weisbecker wrote: > Extend the resource counter API with a mirror of > res_counter_read_u64() to make it handy to update a resource > counter value from a cgroup subsystem u64 value file. > > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > Acked-by: Paul Menage <paul@paulmenage.org> > Cc: Li Zefan <lizf@cn.fujitsu.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Aditya Kali <adityakali@google.com> > Cc: Oleg Nesterov <oleg@redhat.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Kay Sievers <kay.sievers@vrfy.org> > Cc: Tim Hockin <thockin@hockin.org> > Cc: Tejun Heo <tj@kernel.org> > Cc: Kirill A. Shutemov <kirill@shutemov.name> > Cc: Containers <containers@lists.linux-foundation.org> > --- > include/linux/res_counter.h | 2 ++ > kernel/res_counter.c | 25 +++++++++++++++++++------ > 2 files changed, 21 insertions(+), 6 deletions(-) > > diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h > index c9d625c..1b3fe05 100644 > --- a/include/linux/res_counter.h > +++ b/include/linux/res_counter.h > @@ -82,6 +82,8 @@ int res_counter_memparse_write_strategy(const char *buf, > int res_counter_write(struct res_counter *counter, int member, > const char *buffer, write_strategy_fn write_strategy); > > +void res_counter_write_u64(struct res_counter *counter, int member, u64 val); > + > /* > * the field descriptors. one for each member of res_counter > */ > diff --git a/kernel/res_counter.c b/kernel/res_counter.c > index 34683ef..0faafcc 100644 > --- a/kernel/res_counter.c > +++ b/kernel/res_counter.c > @@ -168,12 +168,26 @@ int res_counter_memparse_write_strategy(const char *buf, > return 0; > } > > +void res_counter_write_u64(struct res_counter *counter, int member, u64 val) > +{ > + unsigned long long *target; > + unsigned long flags; > + > + /* > + * We need the lock to protect against concurrent add/dec on 32 bits. > + * No need to ifdef it's seldom used. > + */
Should we hace two version of res_counter_write_u64() for 32/64 bit host? As with res_counter_read_u64().
> + spin_lock_irqsave(&counter->lock, flags); > + target = res_counter_member(counter, member); > + *target = val; > + spin_unlock_irqrestore(&counter->lock, flags); > +} > + > int res_counter_write(struct res_counter *counter, int member, > const char *buf, write_strategy_fn write_strategy) > { > char *end; > - unsigned long flags; > - unsigned long long tmp, *val; > + unsigned long long tmp; > > if (write_strategy) { > if (write_strategy(buf, &tmp)) > @@ -183,9 +197,8 @@ int res_counter_write(struct res_counter *counter, int member, > if (*end != '\0') > return -EINVAL; > } > - spin_lock_irqsave(&counter->lock, flags); > - val = res_counter_member(counter, member); > - *val = tmp; > - spin_unlock_irqrestore(&counter->lock, flags); > + > + res_counter_write_u64(counter, member, tmp); > + > return 0; > } > -- > 1.7.5.4 >
-- Kirill A. Shutemov
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