Re: Low TCP throughput due to vmpressure with swap enabled

On Mon, Nov 21, 2022 at 5:53 PM Ivan Babrou [off-list ref] wrote:

Hello,

We have observed a negative TCP throughput behavior from the following commit:

* 8e8ae645249b mm: memcontrol: hook up vmpressure to socket pressure

It landed back in 2016 in v4.5, so it's not exactly a new issue.

The crux of the issue is that in some cases with swap present the
workload can be unfairly throttled in terms of TCP throughput.

I am able to reproduce this issue in a VM locally on v6.1-rc6 with 8
GiB of RAM with zram enabled.

Hi Ivan,

If it's not too much trouble, could you try again with the following?
  CONFIG_LRU_GEN=y
  CONFIG_LRU_GEN_ENABLED=y

I haven't tried it myself. But I'll fix whatever doesn't work for you,
since your team is on the top of my customer list :)

Thanks.