Messages in this thread | | | Date | Wed, 12 Dec 2018 20:26:39 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH 1/8] perf: Allow to block process in syscall tracepoints |
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On Thu, 13 Dec 2018 03:39:38 +0300 "Dmitry V. Levin" <ldv@altlinux.org> wrote:
> btw, I didn't ask for the implementation to be ugly. > You don't have to introduce polling into the kernel if you don't want to, > userspace is perfectly capable of invoking wait4(2) in a loop. > Just block the tracee, notify the tracer, and let it pick up the pieces.
Note, there's been some discussion offlist to only have perf set a flag when it dropped an event and have the ptrace code do the heavy lifting of blocking the task and waking it back up. I think that would be a cleaner solution and wont muck with perf as badly.
-- Steve
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