On Mon, 31 Jan 2011 15:03:54 +0100
Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
> +static inline bool res_counter_check_margin(struct res_counter *cnt,
> + unsigned long bytes)
> +{
> + bool ret;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&cnt->lock, flags);
> + ret = cnt->limit - cnt->usage >= bytes;
> + spin_unlock_irqrestore(&cnt->lock, flags);
> + return ret;
> +}
> +
> static inline bool res_counter_check_under_soft_limit(struct res_counter *cnt)
> {
> bool ret;
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 73ea323..c28072f 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -1111,6 +1111,15 @@ static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
> return false;
> }
>
> +static bool mem_cgroup_check_margin(struct mem_cgroup *mem, unsigned long bytes)
> +{
> + if (!res_counter_check_margin(&mem->res, bytes))
> + return false;
> + if (do_swap_account && !res_counter_check_margin(&mem->memsw, bytes))
> + return false;
> + return true;
> +}
argh.
If you ever have a function with the string "check" in its name, it's a
good sign that you did something wrong.
Check what? Against what? Returning what?
mem_cgroup_check_under_limit() isn't toooo bad - the name tells you
what's being checked and tells you what to expect the return value to
mean.
But "res_counter_check_margin" and "mem_cgroup_check_margin" are just
awful. Something like
bool res_counter_may_charge(counter, bytes)
would be much clearer.
If we really want to stick with the "check" names (perhaps as an ironic
reference to res_counter's past mistakes) then please at least document
the sorry things?
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>