Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage!

From: Andi Kleen
Date: Mon Nov 21 2016 - 15:44:51 EST


> > http://halobates.de/tracepoint-trace
>
> There's a lot of push and pop regs due to function calling. There's
> places that inlines can still improve things, and perhaps even some
> likely unlikelys well placed.

Assuming you avoid all the push/pop and all the call/ret this would only be
~25% of the total instructions. There is just far too much logic and
computation in there.

% awk ' { print $5 } ' tracepoint-trace | sort | uniq -c | sort -rn
222 mov
57 push
57 pop
35 test
34 cmp
32 and
28 jz
25 jnz
21 ret
20 call
16 lea
11 add

-Andi