Messages in this thread | | | Subject | Re: Re: [PATCH 1/5] ftrace: Synchronize variable setting with breakpoints | From | Steven Rostedt <> | Date | Fri, 01 Jun 2012 07:37:07 -0400 |
| |
On Fri, 2012-06-01 at 13:53 +0900, Masami Hiramatsu wrote:
> Hmm, why don't we have two text_poke interfaces for single and > batch? As like dyn_ftrace, since modifying massive points takes > a lot time, so we may have additional kconfig something like > CONFIG_QUICK_BATCH_TEXT_POKE which switches text area to rw while > batch text_poke. >
I'll be working on patches to consolidate the two after I get everything else working :-) I still need to work on the ftrace kprobe stuff too.
I hate having a config option to switch between the two, except for something that can be there if we find the new approach is buggy (like we have with lockdep). That may be a solution for this if we don't agree on one now. That is, bring back stop_machine() when LOCKDEP is enabled. But that should only be a temporary work around not a true fix.
I have no problem with having most of the modifying code be shared between text_poke and ftrace. I guess the question is, do we want to do it only with the FIXMAP or do we want text_poke and ftrace to use the rw method for large batches. Heck, we can set a limit. If we are going to update more that 100 locations, we switch the kernel to rw, otherwise we do the FIXMAP update.
-- Steve
| |