Re: Lockless uidinfo.

John Baldwin wrote:

Memory barriers on another CPU don't mean anything about the CPU thread 2 is on.

Of course they do. Otherwise they would be completely useless.

> Memory barriers do not flush caches on other CPUs, etc.

Membars are not about caches, but about visibility and ordering. Cache is transparent and that is guaranteed by hardware - there is no need to involve any software tricks to make cache work correctly. You can influence their performance, but not correctness.

--
Maciej Sobczak : http://www.msobczak.com/
Programming : http://www.msobczak.com/prog/
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