Re: [PATCH v3 0/4] Some new features for the latency tracers
From: Steven Rostedt
Date: Tue May 14 2019 - 12:52:47 EST
On Mon, 13 May 2019 23:50:04 +0200
Viktor Rosendahl <viktor.rosendahl@xxxxxxxxx> wrote:
> Hello all,
Note, as the merge window is open and I'm also currently at a
conference, it may be a while before I can take a look at this. If you
don't hear something from me in 10 days, feel free to send me a ping.
> Changes in v3:
> - [PATCH 1/4]:
> * I have generalized this to send the fsnotify() notifications for all
> tracers that use tracing_max_latency.
> * There are large additions of code to prevent queue_work() from being
> called while we are in __schedule() or do_idle(). This was a bug also
> in the previous version but had gone unnoticed. It became very visible
> when I tried to make it work with the wakeup tracers because they are
> always invoked from the sched_switch tracepoint.
> * The fsnotify notification is issued for tracing_max_latency, not trace.
> * I got rid of the kernel config option. The facility is always compiled
> when CONFIG_FSNOTIFY is enabled and any of the latency tracers are
> - [PATCH 2/4]:
> * No significant changes.
> - [PATCH 3/4]:
> * The latency-collector help messages have been tuned to the fact that it
> can be used also with wakeup and hwlat tracers.
> * I increased the size of the buffer for reading from
> * Adapted it to monitor tracing_max_latency instead of trace
> - [PATCH 4/4]:
> * I converted this from a kernel config option to a trace config option
> that can be changed at runtime.