Re: [PATCH v2 1/5] cgroups: Refactor children cgroups in memcg tests

From: Roman Gushchin
Date: Mon Apr 25 2022 - 21:56:21 EST


On Sat, Apr 23, 2022 at 08:56:17AM -0700, David Vernet wrote:
> In test_memcg_min() and test_memcg_low(), there is an array of four sibling
> cgroups. All but one of these sibling groups does a 50MB allocation, and
> the group that does no allocation is the third of four in the array. This
> is not a problem per se, but makes it a bit tricky to do some assertions in
> test_memcg_low(), as we want to make assertions on the siblings based on
> whether or not they performed allocations. Having a static index before
> which all groups have performed an allocation makes this cleaner.
>
> This patch therefore reorders the sibling groups so that the group that
> performs no allocations is the last in the array. A follow-on patch will
> leverage this to fix a bug in the test that incorrectly asserts that a
> sibling group that had performed an allocation, but only had protection
> from its parent, will not observe any memory.events.low events during
> reclaim.
>
> Signed-off-by: David Vernet <void@xxxxxxxxxxxxx>

Acked-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>

Thanks!