3 ms·
How big of an issue is context switching in the middle of a sequence of AMX operations?
by im3w1l 6y ago
How big of an issue is context switching in the middle of a sequence of AMX operations?
- jcranmer 6y agoThe AMX extensions drop 2 more components into XSAVE: XTILECFG (which is 64 bytes) and XTILEDATA (8192 bytes). Interestingly, there does seem to be a new extension (see §3.2.6 of https://software.intel.com/content/www/us/en/develop/download/intel-architecture-instruction-set-extensions-programming-reference.html https://software.intel.com/content/www/us/en/develop/downloa...) that, on first glance, looks to be a per-thread enable/disable bit for using these registers, which suggests that an OS could make a process-level capability to enable/disable AMX and thereby not bother saving these registers on context switches if it's switching to a process without AMX.