Re: [PATCH] mm: memcontrol: don't throttle dying tasks on memory.high

From: Michal Hocko
Date: Fri Jan 12 2024 - 12:07:13 EST


On Thu 11-01-24 14:28:07, Johannes Weiner wrote:
[...]
> @@ -2867,11 +2882,17 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
> }
> } while ((memcg = parent_mem_cgroup(memcg)));
>
> + /*
> + * Reclaim is set up above to be called from the userland
> + * return path. But also attempt synchronous reclaim to avoid
> + * excessive overrun while the task is still inside the
> + * kernel. If this is successful, the return path will see it
> + * when it rechecks the overage and simply bail out.
> + */
> if (current->memcg_nr_pages_over_high > MEMCG_CHARGE_BATCH &&
> !(current->flags & PF_MEMALLOC) &&
> - gfpflags_allow_blocking(gfp_mask)) {
> + gfpflags_allow_blocking(gfp_mask))
> mem_cgroup_handle_over_high(gfp_mask);

Have you lost the check for the dying task here?

Other than that looks good to me.
--
Michal Hocko
SUSE Labs