Bruno Prémont writes:
On Thu, 9 Apr 2020 16:24:17 +0100 wrote:
Bruno Prémont writes:
>Could it be that cache is being prevented from being reclaimed by a task
>in another cgroup?
>
>e.g.
> cgroup/system/backup
> first reads $files (reads each once)
> cgroup/workload/bla
> second&more reads $files
>
>Would $files remain associated to cgroup/system/backup and not
>reclaimed there instead of being reassigned to cgroup/workload/bla?
Yes, that's entirely possible. The first cgroup to fault in the pages is
charged for the memory. Other cgroups may use them, but they are not accounted
for as part of that other cgroup. They may also still be "active" as a result
of use by another cgroup.
But the memory would then be 'active' in the original cgroup? which is
not the case here I feel.
Yes, that's correct. I don't think it's the case here (since active_file is not
that large in the affected cgroup), but it's certainly generally a possibility.
