3 ms·
It's not clear to me this fix will have any performance impact. I strongly suspect it will be negligible or zero. This seems like a "simple" bug of the type th
by arp242 3y ago
It's not clear to me this fix will have any performance impact. I strongly suspect it will be negligible or zero.
This seems like a "simple" bug of the type that people write every day, not deep architectural problems like Spectre and the like, which also affected AMD (in roughly equal measure if I recall correctly).
- kmeisthax 3y agoParent commenter might be thinking of Meltdown, a related architectural bug that only bit Intel and IBM PPC. Everything with speculative execution has Spectre[0], but you only have Meltdown if you speculate across security boundaries. The reason why Meltdown has a more dramatic name than Spectre, despite being the same vulnerability, is that hardware privilege boundaries are the only defensible boundary against timing attacks. We already expect context switches to be expensive, so we're allowed to make them a little more expensive. It'd be prohibitively expensive to avoid leaking timing from, say, one executable library to a block of JIT compiled JavaScript code within the same browser content process. [0] https://randomascii.wordpress.com/2018/01/07/finding-a-cpu-design-bug-in-the-xbox-360/ https://randomascii.wordpress.com/2018/01/07/finding-a-cpu-d...