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* [PATCH v2] mm/damon/dbgfs: remove unnecessary variables
@ 2021-10-14  2:03 Rongwei Wang
  2021-10-14  7:21 ` SeongJae Park
  0 siblings, 1 reply; 3+ messages in thread
From: Rongwei Wang @ 2021-10-14  2:03 UTC (permalink / raw)
  To: sj, akpm; +Cc: linux-kernel, linux-mm

In some functions, it's unnecessary to declare 'err'
and 'ret' variables at the same time. This patch mainly
to simplify the issue of such declarations by reusing
one variable.

Signed-off-by: Rongwei Wang <rongwei.wang@linux.alibaba.com>
---
 mm/damon/dbgfs.c | 66 +++++++++++++++++++++++-------------------------
 1 file changed, 31 insertions(+), 35 deletions(-)

diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index 28d6abf27763..5cd4932800df 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -69,8 +69,7 @@ static ssize_t dbgfs_attrs_write(struct file *file,
 	struct damon_ctx *ctx = file->private_data;
 	unsigned long s, a, r, minr, maxr;
 	char *kbuf;
-	ssize_t ret = count;
-	int err;
+	ssize_t ret;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
@@ -88,9 +87,9 @@ static ssize_t dbgfs_attrs_write(struct file *file,
 		goto unlock_out;
 	}
 
-	err = damon_set_attrs(ctx, s, a, r, minr, maxr);
-	if (err)
-		ret = err;
+	ret = damon_set_attrs(ctx, s, a, r, minr, maxr);
+	if (!ret)
+		ret = count;
 unlock_out:
 	mutex_unlock(&ctx->kdamond_lock);
 out:
@@ -220,14 +219,13 @@ static ssize_t dbgfs_schemes_write(struct file *file, const char __user *buf,
 	struct damon_ctx *ctx = file->private_data;
 	char *kbuf;
 	struct damos **schemes;
-	ssize_t nr_schemes = 0, ret = count;
-	int err;
+	ssize_t nr_schemes = 0, ret;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
 		return PTR_ERR(kbuf);
 
-	schemes = str_to_schemes(kbuf, ret, &nr_schemes);
+	schemes = str_to_schemes(kbuf, count, &nr_schemes);
 	if (!schemes) {
 		ret = -EINVAL;
 		goto out;
@@ -239,11 +237,12 @@ static ssize_t dbgfs_schemes_write(struct file *file, const char __user *buf,
 		goto unlock_out;
 	}
 
-	err = damon_set_schemes(ctx, schemes, nr_schemes);
-	if (err)
-		ret = err;
-	else
+	ret = damon_set_schemes(ctx, schemes, nr_schemes);
+	if (!ret) {
+		ret = count;
 		nr_schemes = 0;
+	}
+
 unlock_out:
 	mutex_unlock(&ctx->kdamond_lock);
 	free_schemes_arr(schemes, nr_schemes);
@@ -342,9 +341,8 @@ static ssize_t dbgfs_target_ids_write(struct file *file,
 	char *kbuf, *nrs;
 	unsigned long *targets;
 	ssize_t nr_targets;
-	ssize_t ret = count;
+	ssize_t ret;
 	int i;
-	int err;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
@@ -352,7 +350,7 @@ static ssize_t dbgfs_target_ids_write(struct file *file,
 
 	nrs = kbuf;
 
-	targets = str_to_target_ids(nrs, ret, &nr_targets);
+	targets = str_to_target_ids(nrs, count, &nr_targets);
 	if (!targets) {
 		ret = -ENOMEM;
 		goto out;
@@ -378,11 +376,12 @@ static ssize_t dbgfs_target_ids_write(struct file *file,
 		goto unlock_out;
 	}
 
-	err = damon_set_targets(ctx, targets, nr_targets);
-	if (err) {
+	ret = damon_set_targets(ctx, targets, nr_targets);
+	if (ret) {
 		if (targetid_is_pid(ctx))
 			dbgfs_put_pids(targets, nr_targets);
-		ret = err;
+	} else {
+		ret = count;
 	}
 
 unlock_out:
@@ -548,8 +547,7 @@ static ssize_t dbgfs_mk_context_write(struct file *file,
 {
 	char *kbuf;
 	char *ctx_name;
-	ssize_t ret = count;
-	int err;
+	ssize_t ret;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
@@ -567,9 +565,9 @@ static ssize_t dbgfs_mk_context_write(struct file *file,
 	}
 
 	mutex_lock(&damon_dbgfs_lock);
-	err = dbgfs_mk_context(ctx_name);
-	if (err)
-		ret = err;
+	ret = dbgfs_mk_context(ctx_name);
+	if (!ret)
+		ret = count;
 	mutex_unlock(&damon_dbgfs_lock);
 
 out:
@@ -638,8 +636,7 @@ static ssize_t dbgfs_rm_context_write(struct file *file,
 		const char __user *buf, size_t count, loff_t *ppos)
 {
 	char *kbuf;
-	ssize_t ret = count;
-	int err;
+	ssize_t ret;
 	char *ctx_name;
 
 	kbuf = user_input_str(buf, count, ppos);
@@ -658,9 +655,9 @@ static ssize_t dbgfs_rm_context_write(struct file *file,
 	}
 
 	mutex_lock(&damon_dbgfs_lock);
-	err = dbgfs_rm_context(ctx_name);
-	if (err)
-		ret = err;
+	ret = dbgfs_rm_context(ctx_name);
+	if (!ret)
+		ret = count;
 	mutex_unlock(&damon_dbgfs_lock);
 
 out:
@@ -684,9 +681,8 @@ static ssize_t dbgfs_monitor_on_read(struct file *file,
 static ssize_t dbgfs_monitor_on_write(struct file *file,
 		const char __user *buf, size_t count, loff_t *ppos)
 {
-	ssize_t ret = count;
+	ssize_t ret;
 	char *kbuf;
-	int err;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
@@ -699,14 +695,14 @@ static ssize_t dbgfs_monitor_on_write(struct file *file,
 	}
 
 	if (!strncmp(kbuf, "on", count))
-		err = damon_start(dbgfs_ctxs, dbgfs_nr_ctxs);
+		ret = damon_start(dbgfs_ctxs, dbgfs_nr_ctxs);
 	else if (!strncmp(kbuf, "off", count))
-		err = damon_stop(dbgfs_ctxs, dbgfs_nr_ctxs);
+		ret = damon_stop(dbgfs_ctxs, dbgfs_nr_ctxs);
 	else
-		err = -EINVAL;
+		ret = -EINVAL;
 
-	if (err)
-		ret = err;
+	if (!ret)
+		ret = count;
 	kfree(kbuf);
 	return ret;
 }
-- 
2.27.0



^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] mm/damon/dbgfs: remove unnecessary variables
  2021-10-14  2:03 [PATCH v2] mm/damon/dbgfs: remove unnecessary variables Rongwei Wang
@ 2021-10-14  7:21 ` SeongJae Park
  2021-10-14  7:30   ` [PATCH v3] " SeongJae Park
  0 siblings, 1 reply; 3+ messages in thread
From: SeongJae Park @ 2021-10-14  7:21 UTC (permalink / raw)
  To: Rongwei Wang; +Cc: sj, akpm, linux-kernel, linux-mm

On Thu, 14 Oct 2021 10:03:33 +0800 Rongwei Wang <rongwei.wang@linux.alibaba.com> wrote:

> In some functions, it's unnecessary to declare 'err'
> and 'ret' variables at the same time. This patch mainly
> to simplify the issue of such declarations by reusing
> one variable.
> 
> Signed-off-by: Rongwei Wang <rongwei.wang@linux.alibaba.com>

Looks good to me.  However, this doesn't cleanly applicable on latest -mm tree.
I will post a rebased version as a reply to this.


Thanks,
SJ

[...]


^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH v3] mm/damon/dbgfs: remove unnecessary variables
  2021-10-14  7:21 ` SeongJae Park
@ 2021-10-14  7:30   ` SeongJae Park
  0 siblings, 0 replies; 3+ messages in thread
From: SeongJae Park @ 2021-10-14  7:30 UTC (permalink / raw)
  Cc: akpm, linux-kernel, linux-mm, Rongwei Wang, SeongJae Park

From: Rongwei Wang <rongwei.wang@linux.alibaba.com>

In some functions, it's unnecessary to declare 'err'
and 'ret' variables at the same time. This patch mainly
to simplify the issue of such declarations by reusing
one variable.

Signed-off-by: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
---
Changes from v2
(https://lore.kernel.org/linux-mm/20211014020333.10330-1-rongwei.wang@linux.alibaba.com/)
- Rebased on latest -mm tree (v5.15-rc5-mmots-2021-10-13-19-55)

 mm/damon/dbgfs.c | 66 +++++++++++++++++++++++-------------------------
 1 file changed, 31 insertions(+), 35 deletions(-)

diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index 38188347d8ab..c90988a20fa4 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -69,8 +69,7 @@ static ssize_t dbgfs_attrs_write(struct file *file,
 	struct damon_ctx *ctx = file->private_data;
 	unsigned long s, a, r, minr, maxr;
 	char *kbuf;
-	ssize_t ret = count;
-	int err;
+	ssize_t ret;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
@@ -88,9 +87,9 @@ static ssize_t dbgfs_attrs_write(struct file *file,
 		goto unlock_out;
 	}
 
-	err = damon_set_attrs(ctx, s, a, r, minr, maxr);
-	if (err)
-		ret = err;
+	ret = damon_set_attrs(ctx, s, a, r, minr, maxr);
+	if (!ret)
+		ret = count;
 unlock_out:
 	mutex_unlock(&ctx->kdamond_lock);
 out:
@@ -220,14 +219,13 @@ static ssize_t dbgfs_schemes_write(struct file *file, const char __user *buf,
 	struct damon_ctx *ctx = file->private_data;
 	char *kbuf;
 	struct damos **schemes;
-	ssize_t nr_schemes = 0, ret = count;
-	int err;
+	ssize_t nr_schemes = 0, ret;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
 		return PTR_ERR(kbuf);
 
-	schemes = str_to_schemes(kbuf, ret, &nr_schemes);
+	schemes = str_to_schemes(kbuf, count, &nr_schemes);
 	if (!schemes) {
 		ret = -EINVAL;
 		goto out;
@@ -239,11 +237,12 @@ static ssize_t dbgfs_schemes_write(struct file *file, const char __user *buf,
 		goto unlock_out;
 	}
 
-	err = damon_set_schemes(ctx, schemes, nr_schemes);
-	if (err)
-		ret = err;
-	else
+	ret = damon_set_schemes(ctx, schemes, nr_schemes);
+	if (!ret) {
+		ret = count;
 		nr_schemes = 0;
+	}
+
 unlock_out:
 	mutex_unlock(&ctx->kdamond_lock);
 	free_schemes_arr(schemes, nr_schemes);
@@ -343,9 +342,8 @@ static ssize_t dbgfs_target_ids_write(struct file *file,
 	char *kbuf, *nrs;
 	unsigned long *targets;
 	ssize_t nr_targets;
-	ssize_t ret = count;
+	ssize_t ret;
 	int i;
-	int err;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
@@ -358,7 +356,7 @@ static ssize_t dbgfs_target_ids_write(struct file *file,
 		scnprintf(kbuf, count, "42    ");
 	}
 
-	targets = str_to_target_ids(nrs, ret, &nr_targets);
+	targets = str_to_target_ids(nrs, count, &nr_targets);
 	if (!targets) {
 		ret = -ENOMEM;
 		goto out;
@@ -393,11 +391,12 @@ static ssize_t dbgfs_target_ids_write(struct file *file,
 	else
 		damon_pa_set_primitives(ctx);
 
-	err = damon_set_targets(ctx, targets, nr_targets);
-	if (err) {
+	ret = damon_set_targets(ctx, targets, nr_targets);
+	if (ret) {
 		if (id_is_pid)
 			dbgfs_put_pids(targets, nr_targets);
-		ret = err;
+	} else {
+		ret = count;
 	}
 
 unlock_out:
@@ -715,8 +714,7 @@ static ssize_t dbgfs_mk_context_write(struct file *file,
 {
 	char *kbuf;
 	char *ctx_name;
-	ssize_t ret = count;
-	int err;
+	ssize_t ret;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
@@ -734,9 +732,9 @@ static ssize_t dbgfs_mk_context_write(struct file *file,
 	}
 
 	mutex_lock(&damon_dbgfs_lock);
-	err = dbgfs_mk_context(ctx_name);
-	if (err)
-		ret = err;
+	ret = dbgfs_mk_context(ctx_name);
+	if (!ret)
+		ret = count;
 	mutex_unlock(&damon_dbgfs_lock);
 
 out:
@@ -805,8 +803,7 @@ static ssize_t dbgfs_rm_context_write(struct file *file,
 		const char __user *buf, size_t count, loff_t *ppos)
 {
 	char *kbuf;
-	ssize_t ret = count;
-	int err;
+	ssize_t ret;
 	char *ctx_name;
 
 	kbuf = user_input_str(buf, count, ppos);
@@ -825,9 +822,9 @@ static ssize_t dbgfs_rm_context_write(struct file *file,
 	}
 
 	mutex_lock(&damon_dbgfs_lock);
-	err = dbgfs_rm_context(ctx_name);
-	if (err)
-		ret = err;
+	ret = dbgfs_rm_context(ctx_name);
+	if (!ret)
+		ret = count;
 	mutex_unlock(&damon_dbgfs_lock);
 
 out:
@@ -851,9 +848,8 @@ static ssize_t dbgfs_monitor_on_read(struct file *file,
 static ssize_t dbgfs_monitor_on_write(struct file *file,
 		const char __user *buf, size_t count, loff_t *ppos)
 {
-	ssize_t ret = count;
+	ssize_t ret;
 	char *kbuf;
-	int err;
 
 	kbuf = user_input_str(buf, count, ppos);
 	if (IS_ERR(kbuf))
@@ -866,14 +862,14 @@ static ssize_t dbgfs_monitor_on_write(struct file *file,
 	}
 
 	if (!strncmp(kbuf, "on", count))
-		err = damon_start(dbgfs_ctxs, dbgfs_nr_ctxs);
+		ret = damon_start(dbgfs_ctxs, dbgfs_nr_ctxs);
 	else if (!strncmp(kbuf, "off", count))
-		err = damon_stop(dbgfs_ctxs, dbgfs_nr_ctxs);
+		ret = damon_stop(dbgfs_ctxs, dbgfs_nr_ctxs);
 	else
-		err = -EINVAL;
+		ret = -EINVAL;
 
-	if (err)
-		ret = err;
+	if (!ret)
+		ret = count;
 	kfree(kbuf);
 	return ret;
 }
-- 
2.17.1



^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-10-14  7:30 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-10-14  2:03 [PATCH v2] mm/damon/dbgfs: remove unnecessary variables Rongwei Wang
2021-10-14  7:21 ` SeongJae Park
2021-10-14  7:30   ` [PATCH v3] " SeongJae Park

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