3 ms·
It probably isn’t worth digging too much into what was essentially a joke. I think the claim is that one would sufficiently trust the safety guarantees of the c
by dan-robertson 3y ago
It probably isn’t worth digging too much into what was essentially a joke. I think the claim is that one would sufficiently trust the safety guarantees of the compiler/runtime to not need any runtime memory protection (software or hardware).
The hardware mmu does have costs: tlbs are quite small and looking things up in a several-layer tree adds a lot of latency. If vm were fine, no one would care much about hugepages, and yet people do care about them. (Larger pages means fewer tlb misses and fewer levels in the tree to look up when there is a miss)
- dist1ll 3y agoI wouldn't call TLBs small: > Consequently, modern processors have extremely large and highly associative two-level TLBs per CPU — for example, Intel’s Skylake chip uses 64-entry level-1 (L1) TLBs and 12-way, 1,536-entry level-2 (L2) TLBs. These structures require almost as much area as L1 caches today, and can consume as much as 10 to 15 percent of the chip energy. Bhattacharjee, Abhishek. "Preserving virtual memory by mitigating the address translation wall." IEEE Micro 37.5 (2017): 6-10.