Re: [PATCH] mm/damon/sysfs: change few functions execute order

From: haoxin
Date: Fri Sep 09 2022 - 21:04:44 EST



在 2022/9/10 上午6:44, Andrew Morton 写道:
On Thu, 8 Sep 2022 22:16:53 +0000 SeongJae Park <sj@xxxxxxxxxx> wrote:

Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
Cool. I rewrote the changelog significantly:

Thanks for all of your hard work and detailed review !


From: Xin Hao <xhao@xxxxxxxxxxxxxxxxx>
Subject: mm/damon/sysfs: change few functions execute order
Date: Thu, 8 Sep 2022 16:19:32 +0800

There's no need to run container_of() as early as we do.

The compiler figures this out, but the resulting code is more readable.

Link: https://lkml.kernel.org/r/20220908081932.77370-1-xhao@xxxxxxxxxxxxxxxxx
Signed-off-by: Xin Hao <xhao@xxxxxxxxxxxxxxxxx>
Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

mm/damon/sysfs.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)

--- a/mm/damon/sysfs.c~mm-damon-sysfs-change-few-functions-execute-order
+++ a/mm/damon/sysfs.c
@@ -1031,8 +1031,7 @@ static ssize_t nr_schemes_show(struct ko
static ssize_t nr_schemes_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
- struct damon_sysfs_schemes *schemes = container_of(kobj,
- struct damon_sysfs_schemes, kobj);
+ struct damon_sysfs_schemes *schemes;
int nr, err = kstrtoint(buf, 0, &nr);
if (err)
@@ -1040,6 +1039,8 @@ static ssize_t nr_schemes_store(struct k
if (nr < 0)
return -EINVAL;
+ schemes = container_of(kobj, struct damon_sysfs_schemes, kobj);
+
if (!mutex_trylock(&damon_sysfs_lock))
return -EBUSY;
err = damon_sysfs_schemes_add_dirs(schemes, nr);
@@ -1237,8 +1238,7 @@ static ssize_t nr_regions_show(struct ko
static ssize_t nr_regions_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
- struct damon_sysfs_regions *regions = container_of(kobj,
- struct damon_sysfs_regions, kobj);
+ struct damon_sysfs_regions *regions;
int nr, err = kstrtoint(buf, 0, &nr);
if (err)
@@ -1246,6 +1246,8 @@ static ssize_t nr_regions_store(struct k
if (nr < 0)
return -EINVAL;
+ regions = container_of(kobj, struct damon_sysfs_regions, kobj);
+
if (!mutex_trylock(&damon_sysfs_lock))
return -EBUSY;
err = damon_sysfs_regions_add_dirs(regions, nr);
@@ -1440,8 +1442,7 @@ static ssize_t nr_targets_show(struct ko
static ssize_t nr_targets_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
- struct damon_sysfs_targets *targets = container_of(kobj,
- struct damon_sysfs_targets, kobj);
+ struct damon_sysfs_targets *targets;
int nr, err = kstrtoint(buf, 0, &nr);
if (err)
@@ -1449,6 +1450,8 @@ static ssize_t nr_targets_store(struct k
if (nr < 0)
return -EINVAL;
+ targets = container_of(kobj, struct damon_sysfs_targets, kobj);
+
if (!mutex_trylock(&damon_sysfs_lock))
return -EBUSY;
err = damon_sysfs_targets_add_dirs(targets, nr);
@@ -1962,8 +1965,7 @@ static ssize_t nr_contexts_show(struct k
static ssize_t nr_contexts_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
- struct damon_sysfs_contexts *contexts = container_of(kobj,
- struct damon_sysfs_contexts, kobj);
+ struct damon_sysfs_contexts *contexts;
int nr, err;
err = kstrtoint(buf, 0, &nr);
@@ -1973,6 +1975,7 @@ static ssize_t nr_contexts_store(struct
if (nr < 0 || 1 < nr)
return -EINVAL;
+ contexts = container_of(kobj, struct damon_sysfs_contexts, kobj);
if (!mutex_trylock(&damon_sysfs_lock))
return -EBUSY;
err = damon_sysfs_contexts_add_dirs(contexts, nr);
@@ -2737,8 +2740,7 @@ static ssize_t nr_kdamonds_show(struct k
static ssize_t nr_kdamonds_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
- struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,
- struct damon_sysfs_kdamonds, kobj);
+ struct damon_sysfs_kdamonds *kdamonds;
int nr, err;
err = kstrtoint(buf, 0, &nr);
@@ -2747,6 +2749,8 @@ static ssize_t nr_kdamonds_store(struct
if (nr < 0)
return -EINVAL;
+ kdamonds = container_of(kobj, struct damon_sysfs_kdamonds, kobj);
+
if (!mutex_trylock(&damon_sysfs_lock))
return -EBUSY;
err = damon_sysfs_kdamonds_add_dirs(kdamonds, nr);
_