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cgroup: Delete unnecessary if statement in css_visible()

PATCH In review Hao Lee 1 participant 3 messages Aug 29, 2020 – Oct 1, 2020 cgroup

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Hao Lee

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#0 lore raw

PATCH 1/1 cgroup: Delete unnecessary if statement in css_visible()

css_visible() is called in either cgroup_apply_control_enable() or cgroup_apply_control_disable().
In cgroup_apply_control_enable(), we have checked ss_mask before calling css_visible(), so there is no need to do the same thing again. In cgroup_apply_control_disable():
- If css->parent is not NULL, we have checked ss_mask in the second condition, so there is no need to do the same thing again.
- If css->parent is NULL, dsct is root cgroup so the deleted if statement is always false and there is no need to keep it.

---
 kernel/cgroup/cgroup.c | 2 --
 1 file changed, 2 deletions(-)
kernel/cgroup/cgroup.c +0 -2
index dd247747ec14..b6714166106d 100644
@@ -3023,8 +3023,6 @@ static bool css_visible(struct cgroup_subsys_state *css)
 
 	if (cgroup_control(cgrp) & (1 << ss->id))
 		return true;
-	if (!(cgroup_ss_mask(cgrp) & (1 << ss->id)))
-		return false;
 	return cgroup_on_dfl(cgrp) && ss->implicit_on_dfl;
 }
 
Signature · 1 line
2.24.1
author
#1 lore raw

Hello,

ping

Quoted 31 lines · Hao Lee

css_visible() is called in either cgroup_apply_control_enable() or cgroup_apply_control_disable().
In cgroup_apply_control_enable(), we have checked ss_mask before calling css_visible(), so there is no need to do the same thing again. In cgroup_apply_control_disable():
- If css->parent is not NULL, we have checked ss_mask in the second condition, so there is no need to do the same thing again.
- If css->parent is NULL, dsct is root cgroup so the deleted if statement is always false and there is no need to keep it.

---
 kernel/cgroup/cgroup.c | 2 --
 1 file changed, 2 deletions(-)
kernel/cgroup/cgroup.c +0 -2
index dd247747ec14..b6714166106d 100644
@@ -3023,8 +3023,6 @@ static bool css_visible(struct cgroup_subsys_state *css)
 
 	if (cgroup_control(cgrp) & (1 << ss->id))
 		return true;
-	if (!(cgroup_ss_mask(cgrp) & (1 << ss->id)))
-		return false;
 	return cgroup_on_dfl(cgrp) && ss->implicit_on_dfl;
 }
 
Signature · 1 line
2.24.1
author
#2 lore raw
In reply to Hao Lee

Hi, ping...

Quoted 31 lines · Hao Lee

css_visible() is called in either cgroup_apply_control_enable() or cgroup_apply_control_disable().
In cgroup_apply_control_enable(), we have checked ss_mask before calling css_visible(), so there is no need to do the same thing again. In cgroup_apply_control_disable():
- If css->parent is not NULL, we have checked ss_mask in the second condition, so there is no need to do the same thing again.
- If css->parent is NULL, dsct is root cgroup so the deleted if statement is always false and there is no need to keep it.

---
 kernel/cgroup/cgroup.c | 2 --
 1 file changed, 2 deletions(-)
kernel/cgroup/cgroup.c +0 -2
index dd247747ec14..b6714166106d 100644
@@ -3023,8 +3023,6 @@ static bool css_visible(struct cgroup_subsys_state *css)
 
 	if (cgroup_control(cgrp) & (1 << ss->id))
 		return true;
-	if (!(cgroup_ss_mask(cgrp) & (1 << ss->id)))
-		return false;
 	return cgroup_on_dfl(cgrp) && ss->implicit_on_dfl;
 }
 
Signature · 1 line
2.24.1