perf: add page (#1561)

pages/linux/perf.md

@@ -0,0 +1,19 @@
+# perf
+
+> Framework for linux performance counter measurements.
+
+- Display basic performance counter stats for a command:
+
+`perf stat {{gcc hello.c}}`
+
+- Display system-wide real time performance counter profile:
+
+`sudo perf top`
+
+- Run a command and record its profile into "perf.data":
+
+`sudo perf record {{command}}`
+
+- Read "perf.data" (created by `perf record`) and display the profile:
+
+`sudo perf report`