From c4c2825c46a89b43ae13154bdb7cc5b5415066b4 Mon Sep 17 00:00:00 2001
From: jichen <jichenjc@cn.ibm.com>
Date: Mon, 30 Oct 2023 07:14:08 +0000
Subject: [PATCH] fix: add page hit

Signed-off-by: jichen <jichenjc@cn.ibm.com>
---
 docs/design/ebpf_in_kepler.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/docs/design/ebpf_in_kepler.md b/docs/design/ebpf_in_kepler.md
index 20d03636..86d34f8e 100644
--- a/docs/design/ebpf_in_kepler.md
+++ b/docs/design/ebpf_in_kepler.md
@@ -130,6 +130,10 @@ HZ = 1000
 
 This value is stored in array `cpu_freq_array`
 
+## Calculate 'page cache hit'
+
+The probe function in kepler `kprobe__set_page_dirty` and `kprobe__mark_page_accessed` are used to track page cache hit for write and read action respectively.
+
 ## Process Table
 
 The bpf program maintains a bpf hash named `processes`. This hash maintains data calculated for a process. Kepler reads values from this hash ( known as a `Table` in bcc ) and generates metrics.