On Fri, Jul 04, 2025 at 03:49:58PM +0900, Shashank Balaji <[email protected]> wrote: > > 1. We don't need to separately check user_usec because it'll always be > > less than user_usec^W usage_usec, and usage_usec is what's directly > > affected by throttling.
When kernel is not preemptible, I'd expect the system time may more easily excess the quota, so I considered the user_usage check less prone to false results. But... > > 2. I changed the >= to > because, not that it'll ever happen, but we can > > let usage_usec = expected_usage_usec pass. Afterall, it's called > > "expected" for a reason. > > Hmm, here is something interesting. The following patch adds printfs to the > existing code to see what user_usec, usage_usec, the expected_usage_usec used > in > the code, and the theoretical expected_usage_usec are. On running the > modified test > a couple of times, here is the output: ...thanks for checking. I was misled by the previous test implementation (the expected_usage_usec had no relation to actual throttled usage in there). What you observe is thus likely explained by the default sched_cfs_bandwidth_slice (5 times the tested quota) and CONFIG_HZ. So I'd say keep only the two-sided tolerant check. (I want to avoid the test to randomly fail when there's no gaping issue.) Thanks, Michal
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