Re: [PATCH] memcg: replace in_interrupt() with !in_task()

From: Michal Hocko
Date: Fri Jan 28 2022 - 07:23:37 EST


On Thu 27-01-22 08:26:36, Shakeel Butt wrote:
> Replace the deprecated in_interrupt() with !in_task() because
> in_interrupt() returns true for BH disabled even if the call happens in
> the task context. in_task() is the right interface to differentiate
> task context from NMI, hard IRQ and softirq contexts.

Makes sense. I do not think this will have any visible effect. Except
for removing a deprecated call, right?

> Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

Thanks!

> ---
> mm/memcontrol.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index d067366002e6..215dfe325e9d 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2688,7 +2688,7 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
> READ_ONCE(memcg->swap.high);
>
> /* Don't bother a random interrupted task */
> - if (in_interrupt()) {
> + if (!in_task()) {
> if (mem_high) {
> schedule_work(&memcg->high_work);
> break;
> @@ -6968,7 +6968,7 @@ void mem_cgroup_sk_alloc(struct sock *sk)
> return;
>
> /* Do not associate the sock with unrelated interrupted task's memcg. */
> - if (in_interrupt())
> + if (!in_task())
> return;
>
> rcu_read_lock();
> --
> 2.35.0.rc0.227.g00780c9af4-goog

--
Michal Hocko
SUSE Labs