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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-01-28 20:51:45 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-01-28 20:51:45 +0100 |
commit | 624441927ff6af871d793dfa49fa347c8450e250 (patch) | |
tree | e86adaab9e82eb357d243b0e27201972a3fbd37b | |
parent | Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/ke... (diff) | |
parent | sched/core: Fix cpu.max vs. cpuhotplug deadlock (diff) | |
download | linux-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.h | 7 | ||||
-rw-r--r-- | kernel/jump_label.c | 12 | ||||
-rw-r--r-- | kernel/sched/fair.c | 4 |
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) |