On 12/26/23 10:01, Steven Rostedt wrote: > From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx> > > When the buffer_percent file was added to the kernel, the documentation > should have been updated to document what that file does. > > Fixes: 03329f9939781 ("tracing: Add tracefs file buffer_percentage") > Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> > --- > Changes since v1: https://lore.kernel.org/all/20231226123525.71a6d0fb@xxxxxxxxxxxxxxxxxx/ > > - Fixed some grammar issues. > > Documentation/trace/ftrace.rst | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst > index 933e7efb9f1b..84b810a6cf76 100644 > --- a/Documentation/trace/ftrace.rst > +++ b/Documentation/trace/ftrace.rst > @@ -180,6 +180,21 @@ of ftrace. Here is a list of some of the key files: > Only active when the file contains a number greater than 0. > (in microseconds) > > + buffer_percent: > + > + This is the water-mark for how much the ring buffer needs to be filled watermark please > + before a waiter is woken up. That is, if an application calls a > + blocking read syscall on one of the per_cpu trace_pipe_raw files, it > + will block until the given amount of data specified by buffer_percent > + is in the ring buffer before it wakes the reader up. This also > + controls how the splice system calls are blocked on this file. > + > + 0 - means to wake up as soon as there is any data in the ring buffer. > + 50 - means to wake up when roughly half of the ring buffer sub-buffers > + are full. > + 100 - means to block until the ring buffer is totally full and is > + about to start overwriting the older data. > + > buffer_size_kb: > > This sets or displays the number of kilobytes each CPU -- #Randy https://people.kernel.org/tglx/notes-about-netiquette https://subspace.kernel.org/etiquette.html