Replace num_cpus with std::thread::available_parallelism
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I think this might help startup time a little bit, since it looks like on linux at least the std implementation uses syscalls to determine the parallelism, whereas num_cpus was processing the /proc/cpuinfo file. It also removes another dependency.
tavianator
changed the title
std::thread::available_parallelism
tavianator
reviewed
Oct 25, 2023
| fn default_num_threads() -> usize { | ||
| // If we can't get the amount of parallelism for some reason, then | ||
| // default to a single thread, because that is safe. | ||
| const FALLBACK_PARALLELISM: NonZeroUsize = NonZeroUsize::MIN; |
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This is a long-winded way of writing 1, right?
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Indeed. Maybe it would be more readable if I changed this to just 1, and used a pattern match?
I debated having the threads method return a NonZeroUsize, but wasn't sure if there was any benefit.
Merged
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I think this might help startup time a little bit, since it looks like on linux at least the std implementation uses syscalls to determine the parallelism, whereas num_cpus was processing the /proc/cpuinfo file.
It also removes another dependency.