Re: [PATCH] cgroup: Remove unnecessary call to strstrip()
On Thu, Jan 14, 2021 at 01:44:27PM +0100, Michal Koutný wrote:
> Hello.
>
> On Sun, Jan 03, 2021 at 02:50:01AM +, Hao Lee
> wrote:
> > The string buf will be stripped in cgroup_procs_write_start() before it
> > is converted to int, so remove this unnecessary call to strstrip().
> Good catch, Hao.
>
> Perhaps the code be then simplified a bit
>
> -- >8 --
> From: =?UTF-8?q?Michal=20Koutn=C3=BD?=
> Date: Thu, 14 Jan 2021 13:23:39 +0100
> Subject: [PATCH] cgroup: cgroup.{procs,threads} factor out common parts
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
>
> The functions cgroup_threads_start and cgroup_procs_start are almost
> identical. In order to reduce duplication, factor out the common code in
> similar fashion we already do for other threadgroup/task functions. No
> functional changes are intended.
>
> Suggested-by: Hao Lee
> Signed-off-by: Michal Koutný
Applied to cgroup/for-5.12 w/ minor description update suggested by Daniel.
Thanks.
--
tejun
Re: [PATCH] cgroup: Remove unnecessary call to strstrip()
> Perhaps the code be then simplified a bit
>
> -- >8 --
> From: =?UTF-8?q?Michal=20Koutn=C3=BD?=
> Date: Thu, 14 Jan 2021 13:23:39 +0100
> Subject: [PATCH] cgroup: cgroup.{procs,threads} factor out common parts
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
>
> The functions cgroup_threads_start and cgroup_procs_start are almost
> identical. In order to reduce duplication, factor out the common code in
> similar fashion we already do for other threadgroup/task functions. No
> functional changes are intended.
Nice work. I didn't realize this simplification :)
Regards,
Hao Lee
Re: [PATCH] cgroup: Remove unnecessary call to strstrip()
Hello Michal,
Michal Koutný writes:
> On Sun, Jan 03, 2021 at 02:50:01AM +, Hao Lee
> wrote:
>> The string buf will be stripped in cgroup_procs_write_start() before it
>> is converted to int, so remove this unnecessary call to strstrip().
> Good catch, Hao.
>
> Perhaps the code be then simplified a bit
>
> -- >8 --
> From: =?UTF-8?q?Michal=20Koutn=C3=BD?=
> Date: Thu, 14 Jan 2021 13:23:39 +0100
> Subject: [PATCH] cgroup: cgroup.{procs,threads} factor out common parts
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
>
> The functions cgroup_threads_start and cgroup_procs_start are almost
You meant cgroup_threads_write and cgroup_procs_write.
> kernel/cgroup/cgroup.c | 55 +++---
> 1 file changed, 14 insertions(+), 41 deletions(-)
Ok, sure, that's a good thing.
Reviewed-by: Daniel Jordan
Re: [PATCH] cgroup: Remove unnecessary call to strstrip()
Hello.
On Sun, Jan 03, 2021 at 02:50:01AM +, Hao Lee
wrote:
> The string buf will be stripped in cgroup_procs_write_start() before it
> is converted to int, so remove this unnecessary call to strstrip().
Good catch, Hao.
Perhaps the code be then simplified a bit
-- >8 --
From: =?UTF-8?q?Michal=20Koutn=C3=BD?=
Date: Thu, 14 Jan 2021 13:23:39 +0100
Subject: [PATCH] cgroup: cgroup.{procs,threads} factor out common parts
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
The functions cgroup_threads_start and cgroup_procs_start are almost
identical. In order to reduce duplication, factor out the common code in
similar fashion we already do for other threadgroup/task functions. No
functional changes are intended.
Suggested-by: Hao Lee
Signed-off-by: Michal Koutný
---
kernel/cgroup/cgroup.c | 55 +++---
1 file changed, 14 insertions(+), 41 deletions(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 613845769103c..f6279df507f4b 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -4726,8 +4726,8 @@ static int cgroup_attach_permissions(struct cgroup
*src_cgrp,
return ret;
}
-static ssize_t cgroup_procs_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
+static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
+ bool threadgroup)
{
struct cgroup *src_cgrp, *dst_cgrp;
struct task_struct *task;
@@ -4738,7 +4738,7 @@ static ssize_t cgroup_procs_write(struct kernfs_open_file
*of,
if (!dst_cgrp)
return -ENODEV;
- task = cgroup_procs_write_start(buf, true, &locked);
+ task = cgroup_procs_write_start(buf, threadgroup, &locked);
ret = PTR_ERR_OR_ZERO(task);
if (ret)
goto out_unlock;
@@ -4748,19 +4748,26 @@ static ssize_t cgroup_procs_write(struct
kernfs_open_file *of,
src_cgrp = task_cgroup_from_root(task, &cgrp_dfl_root);
spin_unlock_irq(&css_set_lock);
+ /* process and thread migrations follow same delegation rule */
ret = cgroup_attach_permissions(src_cgrp, dst_cgrp,
- of->file->f_path.dentry->d_sb, true);
+ of->file->f_path.dentry->d_sb,
threadgroup);
if (ret)
goto out_finish;
- ret = cgroup_attach_task(dst_cgrp, task, true);
+ ret = cgroup_attach_task(dst_cgrp, task, threadgroup);
out_finish:
cgroup_procs_write_finish(task, locked);
out_unlock:
cgroup_kn_unlock(of->kn);
- return ret ?: nbytes;
+ return ret;
+}
+
+static ssize_t cgroup_procs_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ return __cgroup_procs_write(of, buf, true) ?: nbytes;
}
static void *cgroup_threads_start(struct seq_file *s, loff_t *pos)
@@ -4771,41 +4778,7 @@ static void *cgroup_threads_start(struct seq_file *s,
loff_t *pos)
static ssize_t cgroup_threads_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
- struct cgroup *src_cgrp, *dst_cgrp;
- struct task_struct *task;
- ssize_t ret;
- bool locked;
-
- buf = strstrip(buf);
-
- dst_cgrp = cgroup_kn_lock_live(of->kn, false);
- if (!dst_cgrp)
- return -ENODEV;
-
- task = cgroup_procs_write_start(buf, false, &locked);
- ret = PTR_ERR_OR_ZERO(task);
- if (ret)
- goto out_unlock;
-
- /* find the source cgroup */
- spin_lock_irq(&css_set_lock);
- src_cgrp = task_cgroup_from_root(task, &cgrp_dfl_root);
- spin_unlock_irq(&css_set_lock);
-
- /* thread migrations follow the cgroup.procs delegation rule */
- ret = cgroup_attach_permissions(src_cgrp, dst_cgrp,
- of->file->f_path.dentry->d_sb, false);
- if (ret)
- goto out_finish;
-
- ret = cgroup_attach_task(dst_cgrp, task, false);
-
-out_finish:
- cgroup_procs_write_finish(task, locked);
-out_unlock:
- cgroup_kn_unlock(of->kn);
-
- return ret ?: nbytes;
+ return __cgroup_procs_write(of, buf, false) ?: nbytes;
}
/* cgroup core interface files for the default hierarchy */
--
2.29.2
[PATCH] cgroup: Remove unnecessary call to strstrip()
The string buf will be stripped in cgroup_procs_write_start() before it is converted to int, so remove this unnecessary call to strstrip(). Signed-off-by: Hao Lee --- kernel/cgroup/cgroup.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 5e9cb81c088a..8b3554c1113a 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4774,8 +4774,6 @@ static ssize_t cgroup_threads_write(struct kernfs_open_file *of, ssize_t ret; bool locked; - buf = strstrip(buf); - dst_cgrp = cgroup_kn_lock_live(of->kn, false); if (!dst_cgrp) return -ENODEV; -- 2.24.1
Re: [PATCH] cgroup: Remove unnecessary call to strstrip()
Ping. Thanks.
On Tue, Sep 08, 2020 at 01:33:50PM +, Hao Lee wrote:
> The string buf will be stripped in cgroup_procs_write_start() before it
> is converted to int, so remove this unnecessary call to strstrip().
>
> Signed-off-by: Hao Lee
> ---
> kernel/cgroup/cgroup.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
> index b6714166106d..90ee7e73eb2e 100644
> --- a/kernel/cgroup/cgroup.c
> +++ b/kernel/cgroup/cgroup.c
> @@ -4772,14 +4772,12 @@ static ssize_t cgroup_threads_write(struct
> kernfs_open_file *of,
> {
> struct cgroup *src_cgrp, *dst_cgrp;
> struct task_struct *task;
> ssize_t ret;
> bool locked;
>
> - buf = strstrip(buf);
> -
> dst_cgrp = cgroup_kn_lock_live(of->kn, false);
> if (!dst_cgrp)
> return -ENODEV;
>
> task = cgroup_procs_write_start(buf, false, &locked);
> ret = PTR_ERR_OR_ZERO(task);
> --
> 2.24.1
>
[PATCH] cgroup: Remove unnecessary call to strstrip()
The string buf will be stripped in cgroup_procs_write_start() before it
is converted to int, so remove this unnecessary call to strstrip().
Signed-off-by: Hao Lee
---
kernel/cgroup/cgroup.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index b6714166106d..90ee7e73eb2e 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -4772,14 +4772,12 @@ static ssize_t cgroup_threads_write(struct
kernfs_open_file *of,
{
struct cgroup *src_cgrp, *dst_cgrp;
struct task_struct *task;
ssize_t ret;
bool locked;
- buf = strstrip(buf);
-
dst_cgrp = cgroup_kn_lock_live(of->kn, false);
if (!dst_cgrp)
return -ENODEV;
task = cgroup_procs_write_start(buf, false, &locked);
ret = PTR_ERR_OR_ZERO(task);
--
2.24.1
