Re: [PATCH 1/1] mm: vmscan: Reduce throttling due to a failure to make progress

[Alexey Avramov]

I tested this [1] patch on top of 5.16-rc2, the same tests.

- with noswap:

2021-12-02 19:41:19,279: Stall times for the last 146.5s:
2021-12-02 19:41:19,279: -----------
2021-12-02 19:41:19,279: some cpu     1.1s, avg 0.8%
2021-12-02 19:41:19,279: -----------
2021-12-02 19:41:19,279: some io      116.2s, avg 79.3%
2021-12-02 19:41:19,280: full io      109.6s, avg 74.8%
2021-12-02 19:41:19,280: -----------
2021-12-02 19:41:19,280: some memory  3.9s, avg 2.6%
2021-12-02 19:41:19,280: full memory  3.8s, avg 2.6%

Excellent!

psi log:
https://raw.githubusercontent.com/hakavlad/cache-tests/main/516-reclaim-throttle/516-rc2/patch6/noswap/psi

mem log:
https://raw.githubusercontent.com/hakavlad/cache-tests/main/516-reclaim-throttle/516-rc2/patch6/noswap/mem

- with swappiness=0

2021-12-02 19:46:04,860: Stall times for the last 144.5s:
2021-12-02 19:46:04,860: -----------
2021-12-02 19:46:04,860: some cpu     1.1s, avg 0.8%
2021-12-02 19:46:04,860: -----------
2021-12-02 19:46:04,860: some io      106.9s, avg 74.0%
2021-12-02 19:46:04,861: full io      101.3s, avg 70.1%
2021-12-02 19:46:04,861: -----------
2021-12-02 19:46:04,861: some memory  99.6s, avg 68.9%
2021-12-02 19:46:04,861: full memory  95.6s, avg 66.2%

PSI mem pressure was high, but there were no long stalls.

psi log:
https://raw.githubusercontent.com/hakavlad/cache-tests/main/516-reclaim-throttle/516-rc2/patch6/swappiness0/psi

mem log:
https://raw.githubusercontent.com/hakavlad/cache-tests/main/516-reclaim-throttle/516-rc2/patch6/swappiness0/mem

[1] https://lore.kernel.org/all/20211201140005.GU3366@xxxxxxxxxxxxxxxxxxx/