Re: [Qemu-devel] How to measure guest memory access (qemu_ld/qemu_st) time?

[Stefan Hajnoczi]

On Wed, Jun 13, 2012 at 4:14 AM, 陳韋任 (Wei-Ren Chen)
<address@hidden> wrote:
>  I suspect that guest memory access (qemu_ld/qemu_st) account for the major of
> time spent in system mode. I would like to know precisely how much (if 
> possible).
> We use tools like perf [1] before, but since the logic of guest memory access 
> aslo
> embedded in the host binary not only helper functions, the result cannot be
> relied. The current idea is adding helper functions before/after guest memory
> access logic. Take ARM guest on x86_64 host for example, should I add the 
> helper
> functions before/after tcg_gen_qemu_{ld,st} in target-arm/translate.c or
> tcg_out_qemu_{ld,st} in tcg/i386/tcg-target.c? Or there is a better way to 
> know
> how much time QEMU spend on handling guest memory access?

Lluís: Can the instrumentation you've been working on do this?

Stefan