From 4b22a63233e445b8f910023b6f21436c5fa1bf82 Mon Sep 17 00:00:00 2001
From: Frankie Chang <frankie.chang@mediatek.com>
Date: Tue, 12 Jan 2021 14:07:38 +0800
Subject: [PATCH] ANDROID: cgroup: Add vendor hook to the cgroup

Add a vendor hook after attaching a task to a cgroup to
recognize the group_id for performance tuning

Bug: 181917687

Signed-off-by: Frankie Chang <frankie.chang@mediatek.com>
Change-Id: I603afa3d893dd575a7dcb97f83bd9eacb8315bab
(cherry picked from commit bed1e2a75b0000d99a00177272b93e5c8430308b)
---
 drivers/android/vendor_hooks.c |  2 ++
 include/trace/hooks/cgroup.h   | 17 +++++++++++++++++
 kernel/cgroup/cgroup-v1.c      |  2 ++
 3 files changed, 21 insertions(+)
 create mode 100644 include/trace/hooks/cgroup.h

diff --git a/drivers/android/vendor_hooks.c b/drivers/android/vendor_hooks.c
index 6686dbc0f1af..b13367deba9d 100644
--- a/drivers/android/vendor_hooks.c
+++ b/drivers/android/vendor_hooks.c
@@ -20,6 +20,7 @@
 #include <trace/hooks/minidump.h>
 #include <trace/hooks/wqlockup.h>
 #include <trace/hooks/sysrqcrash.h>
+#include <trace/hooks/cgroup.h>
 
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
@@ -69,3 +70,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_sysrq_crash);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_find_busiest_group);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_map_util_freq);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_em_pd_energy);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_cgroup_set_task);
diff --git a/include/trace/hooks/cgroup.h b/include/trace/hooks/cgroup.h
new file mode 100644
index 000000000000..cc44ccf9e109
--- /dev/null
+++ b/include/trace/hooks/cgroup.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM cgroup
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH trace/hooks
+#if !defined(_TRACE_HOOK_CGROUP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HOOK_CGROUP_H
+#include <linux/tracepoint.h>
+#include <trace/hooks/vendor_hooks.h>
+
+struct task_struct;
+DECLARE_HOOK(android_vh_cgroup_set_task,
+	TP_PROTO(int ret, struct task_struct *task),
+	TP_ARGS(ret, task));
+#endif
+
+#include <trace/define_trace.h>
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 7b9ee484abab..c91f8a1e012b 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -17,6 +17,7 @@
 #include <linux/fs_parser.h>
 
 #include <trace/events/cgroup.h>
+#include <trace/hooks/cgroup.h>
 
 #define cg_invalf(fc, fmt, ...) invalf(fc, fmt, ## __VA_ARGS__)
 
@@ -522,6 +523,7 @@ static ssize_t __cgroup1_procs_write(struct kernfs_open_file *of,
 		goto out_finish;
 
 	ret = cgroup_attach_task(cgrp, task, threadgroup);
+	trace_android_vh_cgroup_set_task(ret, task);
 
 out_finish:
 	cgroup_procs_write_finish(task);