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authorLinus Torvalds <torvalds@linux-foundation.org>2018-01-28 20:51:45 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-28 20:51:45 +0100
commit624441927ff6af871d793dfa49fa347c8450e250 (patch)
treee86adaab9e82eb357d243b0e27201972a3fbd37b
parentMerge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/ke... (diff)
parentsched/core: Fix cpu.max vs. cpuhotplug deadlock (diff)
downloadlinux-624441927ff6af871d793dfa49fa347c8450e250.tar.xz
linux-624441927ff6af871d793dfa49fa347c8450e250.zip
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner: "A single bug fix to prevent a subtle deadlock in the scheduler core code vs cpu hotplug" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Fix cpu.max vs. cpuhotplug deadlock
-rw-r--r--include/linux/jump_label.h7
-rw-r--r--kernel/jump_label.c12
-rw-r--r--kernel/sched/fair.c4
3 files changed, 18 insertions, 5 deletions
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index c7b368c734af..e0340ca08d98 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -160,6 +160,8 @@ extern void arch_jump_label_transform_static(struct jump_entry *entry,
extern int jump_label_text_reserved(void *start, void *end);
extern void static_key_slow_inc(struct static_key *key);
extern void static_key_slow_dec(struct static_key *key);
+extern void static_key_slow_inc_cpuslocked(struct static_key *key);
+extern void static_key_slow_dec_cpuslocked(struct static_key *key);
extern void jump_label_apply_nops(struct module *mod);
extern int static_key_count(struct static_key *key);
extern void static_key_enable(struct static_key *key);
@@ -222,6 +224,9 @@ static inline void static_key_slow_dec(struct static_key *key)
atomic_dec(&key->enabled);
}
+#define static_key_slow_inc_cpuslocked(key) static_key_slow_inc(key)
+#define static_key_slow_dec_cpuslocked(key) static_key_slow_dec(key)
+
static inline int jump_label_text_reserved(void *start, void *end)
{
return 0;
@@ -416,6 +421,8 @@ extern bool ____wrong_branch_error(void);
#define static_branch_inc(x) static_key_slow_inc(&(x)->key)
#define static_branch_dec(x) static_key_slow_dec(&(x)->key)
+#define static_branch_inc_cpuslocked(x) static_key_slow_inc_cpuslocked(&(x)->key)
+#define static_branch_dec_cpuslocked(x) static_key_slow_dec_cpuslocked(&(x)->key)
/*
* Normal usage; boolean enable/disable.
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 8594d24e4adc..b4517095db6a 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -79,7 +79,7 @@ int static_key_count(struct static_key *key)
}
EXPORT_SYMBOL_GPL(static_key_count);
-static void static_key_slow_inc_cpuslocked(struct static_key *key)
+void static_key_slow_inc_cpuslocked(struct static_key *key)
{
int v, v1;
@@ -180,7 +180,7 @@ void static_key_disable(struct static_key *key)
}
EXPORT_SYMBOL_GPL(static_key_disable);
-static void static_key_slow_dec_cpuslocked(struct static_key *key,
+static void __static_key_slow_dec_cpuslocked(struct static_key *key,
unsigned long rate_limit,
struct delayed_work *work)
{
@@ -211,7 +211,7 @@ static void __static_key_slow_dec(struct static_key *key,
struct delayed_work *work)
{
cpus_read_lock();
- static_key_slow_dec_cpuslocked(key, rate_limit, work);
+ __static_key_slow_dec_cpuslocked(key, rate_limit, work);
cpus_read_unlock();
}
@@ -229,6 +229,12 @@ void static_key_slow_dec(struct static_key *key)
}
EXPORT_SYMBOL_GPL(static_key_slow_dec);
+void static_key_slow_dec_cpuslocked(struct static_key *key)
+{
+ STATIC_KEY_CHECK_USE(key);
+ __static_key_slow_dec_cpuslocked(key, 0, NULL);
+}
+
void static_key_slow_dec_deferred(struct static_key_deferred *key)
{
STATIC_KEY_CHECK_USE(key);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 2fe3aa853e4d..26a71ebcd3c2 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4365,12 +4365,12 @@ static inline bool cfs_bandwidth_used(void)
void cfs_bandwidth_usage_inc(void)
{
- static_key_slow_inc(&__cfs_bandwidth_used);
+ static_key_slow_inc_cpuslocked(&__cfs_bandwidth_used);
}
void cfs_bandwidth_usage_dec(void)
{
- static_key_slow_dec(&__cfs_bandwidth_used);
+ static_key_slow_dec_cpuslocked(&__cfs_bandwidth_used);
}
#else /* HAVE_JUMP_LABEL */
static bool cfs_bandwidth_used(void)