Re: [PATCH v7 2/8] selftests/cgroup: avoid OOM in test_swapin_nozswap

[Michal Koutný]

On Fri, Apr 24, 2026 at 12:00:53PM +0800, Li Wang <li.wang@xxxxxxxxx> wrote:
> test_swapin_nozswap can hit OOM before reaching its assertions on some
> setups.

Is it because of differences in available IO or what does it depend on?

> The test currently sets memory.max=8M and then allocates/reads
> 32M with memory.zswap.max=0, which may over-constrain reclaim and kill
> the workload process.
> 
> Replace hardcoded sizes with PAGE_SIZE-based values:
>   - control_allocation_size = PAGE_SIZE * 512
>   - memory.max = control_allocation_size * 3 / 4
>   - minimum expected swap = control_allocation_size / 4
> 
> This keeps the test pressure model intact (allocate/read beyond memory.max to
> force swap-in/out) while making it more robust across different environments.

I see you used allocation value that is preserve absolute values from 64k systems
test is differnt on 4k ones. Any specific reason for that?


Thanks,
Michal

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