3 ms·
The kernel is a bit of a special case since very likely a syscall starts off with a cold I$, and also there's a lot of extra overhead if you insist on using SIM
by jabl 4y ago
The kernel is a bit of a special case since very likely a syscall starts off with a cold I$, and also there's a lot of extra overhead if you insist on using SIMD registers.
In general I agree with you though, optimizing memcpy implementations only against microbenchmarks is dumb.
- stncls 4y agoAlso, using SIMD registers is (generally) forbidden in kernel code, which heavily narrows down the competitors to "rep stosb".