Messages in this thread | | | Date | Tue, 6 Feb 2018 00:14:28 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH 00/18] [ANNOUNCE] Dynamically created function based events |
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(Note that I also agree with Linus's opinion that this is like a debugger, since I already did it in perf-probe :))
On Sun, 4 Feb 2018 11:39:39 -0800 Linus Torvalds <torvalds@linux-foundation.org> wrote:
> (Obviously it's not entirely black-and-white, but I do think there is > a pretty big difference between the two groups. And the first group > will obviously use the explicit trace points _too_, generally to > narrow down where they want to go with the function-based one). > > We'll see. Maybe I'm entirely wrong. But I'm hoping that the > function-based one will end up being helpful.
BTW, if the function-based tracing is helpful for both of them, they can start using it back in 2010 because kprobe-based tracer already supported it.
It was less announced, I must admit that I was lazy at that point. Also, since I moved usability effort on perf-probe, kprobe-based event syntax is not so funcy.
"SyS_openat(int dfd, string path, x32 flags, x16 mode)"
is equal to
"p SyS_openat dfd=%di:x64 path=%si:string flags=%dx:x32 mode=%cx:x16"
in kprobe probe definition syntax, but with perf-probe and CONFIG_DEBUG_INFO,
perf probe -a 'sys_openat $params'
will setup the event correctly.
So, we need to clarify what will attract more "2nd group" people to function based events. E.g. the events for EXPORT_SYMBOL_GPL() symbols already defined and easily on/off.
Thank you,
-- Masami Hiramatsu <mhiramat@kernel.org>
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