From 640b2404695cc7d903e56f9426bc1455957c5563 Mon Sep 17 00:00:00 2001
From: Alban Crequy <alban@kinvolk.io>
Date: Fri, 21 Apr 2017 15:02:51 +0200
Subject: [PATCH] proc walker: optimize open file counter

Golang's ReadDirNames is expensive and better avoided when we don't care
about the names.
---
 probe/process/walker_linux.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/probe/process/walker_linux.go b/probe/process/walker_linux.go
index 6c7d1f09c..a748d2bee 100644
--- a/probe/process/walker_linux.go
+++ b/probe/process/walker_linux.go
@@ -102,7 +102,7 @@ func (w *walker) Walk(f func(Process, Process)) error {
 			continue
 		}
 
-		openFiles, err := fs.ReadDirNames(path.Join(w.procRoot, filename, "fd"))
+		openFilesCount, err := fs.ReadDirCount(path.Join(w.procRoot, filename, "fd"))
 		if err != nil {
 			continue
 		}
@@ -139,7 +139,7 @@ func (w *walker) Walk(f func(Process, Process)) error {
 			Jiffies:        jiffies,
 			RSSBytes:       rss,
 			RSSBytesLimit:  rssLimit,
-			OpenFilesCount: len(openFiles),
+			OpenFilesCount: openFilesCount,
 			OpenFilesLimit: openFilesLimit,
 		}, Process{})
 	}