4 ms·
It will show up like CPU usage - the hyperthread that is waiting for memory will appear busy executing. perf can record hardware counter events - use "perf lis
by caf 11y ago
It will show up like CPU usage - the hyperthread that is waiting for memory will appear busy executing.
perf can record hardware counter events - use "perf list" to see the list - including those that count frontend and backend stalls (stalls in the instruction decoding and execution stages respectively). A high stall ratio / low instructions per cycle throughput is an indicator that you're running into memory bandwidth limitations.
- odaymansour 11y agoYou've also reminded me that while they do show up as CPU time, they wouldn't be 'user' time (for example in the output of the command 'time')
- brendangregg 11y agoIf it's user-mode loads and stores, which for applications is pretty common, it is user time. Easy to test.
- odaymansour 11y agoThanks for that, I'll take another look at it and see what I've been missing then.