ifpps: warn about increase -t when high speed

Collecting device statistics on high speed every second can be very
costly, so warn about this in ncurses mode.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/ifpps.8 b/ifpps.8
index c45f6f8..16bbf6d 100644
--- a/ifpps.8
+++ b/ifpps.8
@@ -70,6 +70,10 @@ is only available, if option \[lq]\-c\[rq] is given. For \[lq]\-l\[rq] it is
 usually recommended to redirect the output into a file that is to be be
 processed later with gnuplot(1).
 .PP
+.SS -W, --no-warn
+Suppress possible warnings in the ncurses output, e.g. about a too low sampling
+interval that could cause performance regression.
+.PP
 .SS -v, --version
 Show version information.
 .PP