From 95e3b2c00f82ee88f019dc504fa77baea0456614 Mon Sep 17 00:00:00 2001
From: lk_hauwei <liuke94@huawei.com>
Date: Thu, 23 Jun 2022 20:31:48 +0800
Subject: [PATCH] mm: optimize lowmem_debug code

ohos inclusion
category: bugfix
issue: #I5DUM4
CVE: NA

--------------------------------
Reduce surplus code ,optimize code logic

Signed-off-by: lk_hauwei <liuke94@huawei.com>
---
 mm/lmkd_dbg_trigger.c | 19 +++++++------------
 mm/lowmem_dbg.c       | 36 +++++-------------------------------
 2 files changed, 12 insertions(+), 43 deletions(-)

diff --git a/mm/lmkd_dbg_trigger.c b/mm/lmkd_dbg_trigger.c
index e845b14f5f02..c0b7a758c6b2 100644
--- a/mm/lmkd_dbg_trigger.c
+++ b/mm/lmkd_dbg_trigger.c
@@ -5,16 +5,14 @@
  * Copyright (c) 2020-2022 Huawei Technologies Co., Ltd.
  */
 #include <linux/atomic.h>
-#include <linux/fs.h>
 #include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
 #include <linux/oom.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
-#include <linux/uaccess.h>
 #include <linux/lowmem_dbg.h>
-#define PROC_NUMBUF 8
+
+#define PROC_NUMBUF 3
+#define STATE_BIT 1
 
 static int lmkd_oom_score_adj;
 static atomic64_t lmkd_no_cma_cnt = ATOMIC64_INIT(0);
@@ -61,14 +59,11 @@ static ssize_t lmkd_dbg_trigger_write(struct file *file, const char __user *buf,
 	if (err)
 		goto out;
 
-	if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
-		oom_score_adj > OOM_SCORE_ADJ_MAX) {
+	if (!(oom_score_adj >> STATE_BIT)) {
+		lmkd_oom_score_adj = oom_score_adj;
+		lowmem_dbg(oom_score_adj);
+	} else
 		err = -EINVAL;
-		goto out;
-	}
-
-	lmkd_oom_score_adj = oom_score_adj;
-	lowmem_dbg(oom_score_adj);
 
 out:
 	return err < 0 ? err : count;
diff --git a/mm/lowmem_dbg.c b/mm/lowmem_dbg.c
index fc548ce78fd2..f515d729efb8 100644
--- a/mm/lowmem_dbg.c
+++ b/mm/lowmem_dbg.c
@@ -6,30 +6,17 @@
  */
 #define pr_fmt(fmt) "lowmem:" fmt
 
-#include <linux/module.h>
-#include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/oom.h>
-#include <linux/sched.h>
 #include <linux/rcupdate.h>
-#include <linux/notifier.h>
 #include <linux/mutex.h>
-#include <linux/delay.h>
-#include <linux/swap.h>
-#include <linux/fs.h>
 #include <linux/jiffies.h>
 #include <linux/workqueue.h>
 #include <linux/freezer.h>
-#include <linux/ksm.h>
-#include <linux/io.h>
-#include <linux/version.h>
 #include <linux/lowmem_dbg.h>
 
-#define LMK_PRT_TSK_RSS 10000
 #define LMK_INTERVAL 3
 
-/* SERVICE_ADJ(5) * OOM_SCORE_ADJ_MAX / -OOM_DISABLE */
-#define LMK_SERVICE_ADJ 500
 /* defiine TASK STATE String */
 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPNn"
 
@@ -38,7 +25,6 @@ static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 static void lowmem_dump(struct work_struct *work);
 
 static DEFINE_MUTEX(lowmem_dump_mutex);
-static DECLARE_WORK(lowmem_dbg_wk, lowmem_dump);
 static DECLARE_WORK(lowmem_dbg_verbose_wk, lowmem_dump);
 
 static int task_state_char(unsigned long state)
@@ -48,7 +34,7 @@ static int task_state_char(unsigned long state)
 	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 }
 
-static void tasks_dump(bool verbose)
+static void tasks_dump(void)
 {
 	struct task_struct *p = NULL;
 	struct task_struct *task = NULL;
@@ -56,7 +42,8 @@ static void tasks_dump(bool verbose)
 	unsigned long tsk_nr_ptes = 0;
 	char frozen_mark = ' ';
 
-	pr_info("[ pid ]    uid  tgid total_vm    rss nptes  swap   adj s name\n");
+	pr_info("[%5s] %5s %5s %8s %6s %5s %5s %5s %s %s\n",
+		"pid", "uid", "tgid", "total_vm", "rss", "nptes", "swap", "adj", "s", "name");
 
 	rcu_read_lock();
 	for_each_process(p) {
@@ -71,12 +58,6 @@ static void tasks_dump(bool verbose)
 		}
 
 		tsk_oom_adj = task->signal->oom_score_adj;
-		if (!verbose && tsk_oom_adj &&
-		    (tsk_oom_adj <= LMK_SERVICE_ADJ) &&
-		    (get_mm_rss(task->mm) < LMK_PRT_TSK_RSS)) {
-			task_unlock(task);
-			continue;
-		}
 
 		tsk_nr_ptes = mm_pgtables_bytes(task->mm);
 
@@ -98,16 +79,9 @@ static void tasks_dump(bool verbose)
 
 static void lowmem_dump(struct work_struct *work)
 {
-	bool verbose = (work == &lowmem_dbg_verbose_wk) ? true : false;
-
 	mutex_lock(&lowmem_dump_mutex);
-#if defined(SHOW_MEM_FILTER_PAGE_COUNT)
-	show_mem(SHOW_MEM_FILTER_NODES |
-	    (verbose ? 0 : SHOW_MEM_FILTER_PAGE_COUNT));
-#else
 	show_mem(SHOW_MEM_FILTER_NODES, NULL);
-#endif
-	tasks_dump(verbose);
+	tasks_dump();
 	mutex_unlock(&lowmem_dump_mutex);
 }
 
@@ -119,7 +93,7 @@ void lowmem_dbg(short oom_score_adj)
 		schedule_work(&lowmem_dbg_verbose_wk);
 	} else if (time_after64(jiffs, (last_jiffs + LMK_INTERVAL * HZ))) {
 		last_jiffs = get_jiffies_64();
-		schedule_work(&lowmem_dbg_wk);
+		schedule_work(&lowmem_dbg_verbose_wk);
 	}
 }
 
-- 
Gitee