From de253786000cc3960f19d9852863a8ab5a63f438 Mon Sep 17 00:00:00 2001
From: "Yichun Zhang (agentzh)" <yichun@openresty.com>
Date: Fri, 3 Jan 2020 16:09:07 -0800
Subject: [PATCH] Tapset: proc_mem_rss() now includes resident shared mem
 pages.

The return value finally matches the VmRSS field in /proc/PID/status
now.

The old behavior can be restored by the --compatible=4.2 option
on the command line.

Thanks Dejiang Zhu for reporting this issue.
---
 NEWS                      |  4 ++++
 tapset/linux/proc_mem.stp | 19 +++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index aabace6a1..313d35a5e 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,10 @@
 - The process(EXE).begin probe handlers are now always triggered for
   already-running target processes.
 
+- The proc_mem_rss() tapset function now includes the resident shared
+  memory pages as expected. The old behavior can be restored by the
+  --compatible=4.2 option on the command line.
+
 * What's new in version 4.2, 2019-11-18
 
 - Initial support for multi-dimensional supports has been added to
diff --git a/tapset/linux/proc_mem.stp b/tapset/linux/proc_mem.stp
index 2b152f6ae..1208a2287 100644
--- a/tapset/linux/proc_mem.stp
+++ b/tapset/linux/proc_mem.stp
@@ -71,6 +71,13 @@ enum {
 	return @const("MM_ANONPAGES")
 }
 
+%(systemtap_v > "4.2" %?
+@__private30 function _MM_SHMEMPAGES:long()
+{
+	return @const("MM_SHMEMPAGES")
+}
+%)
+
 @__private30 function _stp_get_mm_counter:long(mm_ptr:long, member:long)
 {
     mm = & @mm(mm_ptr)
@@ -167,7 +174,11 @@ function proc_mem_rss:long ()
     mm = @task(task)->mm
     if (mm != 0)
       return (_stp_get_mm_counter(mm, _MM_FILEPAGES())
-	      + _stp_get_mm_counter(mm, _MM_ANONPAGES()))
+	      + _stp_get_mm_counter(mm, _MM_ANONPAGES())
+%(systemtap_v > "4.2" %?
+	      + _stp_get_mm_counter(mm, _MM_SHMEMPAGES())
+%)
+              )
   }
   return 0
 }
@@ -188,7 +199,11 @@ function proc_mem_rss:long (pid:long)
     mm = @task(task)->mm
     if (mm != 0)
         return (_stp_get_mm_counter(mm, _MM_FILEPAGES())
-                + _stp_get_mm_counter(mm, _MM_ANONPAGES()))
+                + _stp_get_mm_counter(mm, _MM_ANONPAGES())
+%(systemtap_v > "4.2" %?
+	      + _stp_get_mm_counter(mm, _MM_SHMEMPAGES())
+%)
+                )
   }
   return 0
 }
-- 
2.43.5