Re: [PATCH 3/3] x86/ftrace: Use text_poke()

From: Masami Hiramatsu
Date: Thu Oct 03 2019 - 01:52:44 EST


On Wed, 2 Oct 2019 18:35:26 +0200
Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> wrote:

> ftrace was already batching the updates, for instance, causing 3 IPIs to enable
> all functions. The text_poke() batching also works. But because of the limited
> buffer [ see the reply to the patch 2/3 ], it is flushing the buffer during the
> operation, causing more IPIs than the previous code. Using the 5.4-rc1 in a VM,
> when enabling the function tracer, I see 250+ intermediate text_poke_finish()
> because of a full buffer...

Would you have any performance numbers of the previous code and applying this?

Thank you,


--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>