4 ms·
You want the kernel to be able to collect the trace as fast as possible. You don't want to add half a million context switches to your trace.
by rwmj 4y ago
You want the kernel to be able to collect the trace as fast as possible. You don't want to add half a million context switches to your trace.
- quotemstr 4y agoWhere are the extra "context switches"? Can you count them for me? Under my proposal, we defer stack collection until we're going to return to user space anyway. The user stack of a thread cannot change while that thread is running in user mode.
- rwmj 4y agoSo after looking at this, I do now agree [can't edit my original comment]. Are you planning to implement anything like this? I think similar to the suggestion to fix DWARF, enabling frame pointers may not be the best solution, it may be reversed in future when we get something better, but it's the one that actually works right now.