149 lines
4.9 KiB
Diff
149 lines
4.9 KiB
Diff
From f578676705cfd5a2faed7544dcb2973c46bc2c71 Mon Sep 17 00:00:00 2001
|
|
Message-Id: <f578676705cfd5a2faed7544dcb2973c46bc2c71.1601675151.git.zanussi@kernel.org>
|
|
In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
|
|
References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
|
|
From: Ingo Molnar <mingo@elte.hu>
|
|
Date: Fri, 3 Jul 2009 08:30:13 -0500
|
|
Subject: [PATCH 079/333] mm/vmstat: Protect per cpu variables with preempt
|
|
disable on RT
|
|
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz
|
|
|
|
Disable preemption on -RT for the vmstat code. On vanila the code runs in
|
|
IRQ-off regions while on -RT it is not. "preempt_disable" ensures that the
|
|
same ressources is not updated in parallel due to preemption.
|
|
|
|
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
---
|
|
include/linux/vmstat.h | 4 ++++
|
|
mm/vmstat.c | 12 ++++++++++++
|
|
2 files changed, 16 insertions(+)
|
|
|
|
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
|
|
index f25cef84b41d..febee8649220 100644
|
|
--- a/include/linux/vmstat.h
|
|
+++ b/include/linux/vmstat.h
|
|
@@ -54,7 +54,9 @@ DECLARE_PER_CPU(struct vm_event_state, vm_event_states);
|
|
*/
|
|
static inline void __count_vm_event(enum vm_event_item item)
|
|
{
|
|
+ preempt_disable_rt();
|
|
raw_cpu_inc(vm_event_states.event[item]);
|
|
+ preempt_enable_rt();
|
|
}
|
|
|
|
static inline void count_vm_event(enum vm_event_item item)
|
|
@@ -64,7 +66,9 @@ static inline void count_vm_event(enum vm_event_item item)
|
|
|
|
static inline void __count_vm_events(enum vm_event_item item, long delta)
|
|
{
|
|
+ preempt_disable_rt();
|
|
raw_cpu_add(vm_event_states.event[item], delta);
|
|
+ preempt_enable_rt();
|
|
}
|
|
|
|
static inline void count_vm_events(enum vm_event_item item, long delta)
|
|
diff --git a/mm/vmstat.c b/mm/vmstat.c
|
|
index ce81b0a7d018..cfa2a3bbdf91 100644
|
|
--- a/mm/vmstat.c
|
|
+++ b/mm/vmstat.c
|
|
@@ -320,6 +320,7 @@ void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
|
|
long x;
|
|
long t;
|
|
|
|
+ preempt_disable_rt();
|
|
x = delta + __this_cpu_read(*p);
|
|
|
|
t = __this_cpu_read(pcp->stat_threshold);
|
|
@@ -329,6 +330,7 @@ void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
|
|
x = 0;
|
|
}
|
|
__this_cpu_write(*p, x);
|
|
+ preempt_enable_rt();
|
|
}
|
|
EXPORT_SYMBOL(__mod_zone_page_state);
|
|
|
|
@@ -340,6 +342,7 @@ void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
|
|
long x;
|
|
long t;
|
|
|
|
+ preempt_disable_rt();
|
|
x = delta + __this_cpu_read(*p);
|
|
|
|
t = __this_cpu_read(pcp->stat_threshold);
|
|
@@ -349,6 +352,7 @@ void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
|
|
x = 0;
|
|
}
|
|
__this_cpu_write(*p, x);
|
|
+ preempt_enable_rt();
|
|
}
|
|
EXPORT_SYMBOL(__mod_node_page_state);
|
|
|
|
@@ -381,6 +385,7 @@ void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
|
|
s8 __percpu *p = pcp->vm_stat_diff + item;
|
|
s8 v, t;
|
|
|
|
+ preempt_disable_rt();
|
|
v = __this_cpu_inc_return(*p);
|
|
t = __this_cpu_read(pcp->stat_threshold);
|
|
if (unlikely(v > t)) {
|
|
@@ -389,6 +394,7 @@ void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
|
|
zone_page_state_add(v + overstep, zone, item);
|
|
__this_cpu_write(*p, -overstep);
|
|
}
|
|
+ preempt_enable_rt();
|
|
}
|
|
|
|
void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
|
|
@@ -397,6 +403,7 @@ void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
|
|
s8 __percpu *p = pcp->vm_node_stat_diff + item;
|
|
s8 v, t;
|
|
|
|
+ preempt_disable_rt();
|
|
v = __this_cpu_inc_return(*p);
|
|
t = __this_cpu_read(pcp->stat_threshold);
|
|
if (unlikely(v > t)) {
|
|
@@ -405,6 +412,7 @@ void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
|
|
node_page_state_add(v + overstep, pgdat, item);
|
|
__this_cpu_write(*p, -overstep);
|
|
}
|
|
+ preempt_enable_rt();
|
|
}
|
|
|
|
void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
|
|
@@ -425,6 +433,7 @@ void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
|
|
s8 __percpu *p = pcp->vm_stat_diff + item;
|
|
s8 v, t;
|
|
|
|
+ preempt_disable_rt();
|
|
v = __this_cpu_dec_return(*p);
|
|
t = __this_cpu_read(pcp->stat_threshold);
|
|
if (unlikely(v < - t)) {
|
|
@@ -433,6 +442,7 @@ void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
|
|
zone_page_state_add(v - overstep, zone, item);
|
|
__this_cpu_write(*p, overstep);
|
|
}
|
|
+ preempt_enable_rt();
|
|
}
|
|
|
|
void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
|
|
@@ -441,6 +451,7 @@ void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
|
|
s8 __percpu *p = pcp->vm_node_stat_diff + item;
|
|
s8 v, t;
|
|
|
|
+ preempt_disable_rt();
|
|
v = __this_cpu_dec_return(*p);
|
|
t = __this_cpu_read(pcp->stat_threshold);
|
|
if (unlikely(v < - t)) {
|
|
@@ -449,6 +460,7 @@ void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
|
|
node_page_state_add(v - overstep, pgdat, item);
|
|
__this_cpu_write(*p, overstep);
|
|
}
|
|
+ preempt_enable_rt();
|
|
}
|
|
|
|
void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
|
|
--
|
|
2.17.1
|
|
|