arcstat: flush stdout / outfile after each line

Otherwise, if arcstat gets interrupted before the desired number of
iterations is reached, the output file will be empty (both if set via
'-o' or via shell redirection).

Reviewed-by: George Melikov <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Giuseppe Di Natale <[email protected]>
Signed-off-by: Fabian Grünbichler <[email protected]>
Closes #6775 

1 files changed, 1 insertions, 0 deletions

diff --git a/cmd/arcstat/arcstat.py b/cmd/arcstat/arcstat.py
index d969da8d4..aa54ee87a 100755
--- a/cmd/arcstat/arcstat.py
+++ b/cmd/arcstat/arcstat.py
@@ -219,6 +219,7 @@ def print_values():
             sep
         ))
     sys.stdout.write("\n")
+    sys.stdout.flush()
 
 
 def print_header():