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author | Ingo Molnar <mingo@kernel.org> | 2017-06-09 09:17:10 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2017-06-09 09:17:10 +0300 |
commit | 8affb06737ae565722764c2b309eb0e892538344 (patch) | |
tree | 80ee0ce911755a2d30a18c7698ea1424764e8de6 /kernel | |
parent | b29794ec95c6856b316c2295904208bf11ffddd9 (diff) | |
parent | 1123a6041654e8f889014659593bad4168e542c2 (diff) | |
download | linux-8affb06737ae565722764c2b309eb0e892538344.tar.xz |
Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into rcu/urgent
Pull RCU fix from Paul E. McKenney:
" This series enables srcu_read_lock() and srcu_read_unlock() to be used from
interrupt handlers, which fixes a bug in KVM's use of SRCU in delivery
of interrupts to guest OSes. "
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/rcu/srcu.c | 5 | ||||
-rw-r--r-- | kernel/rcu/srcutiny.c | 7 | ||||
-rw-r--r-- | kernel/rcu/srcutree.c | 5 |
3 files changed, 8 insertions, 9 deletions
diff --git a/kernel/rcu/srcu.c b/kernel/rcu/srcu.c index 584d8a983883..dea03614263f 100644 --- a/kernel/rcu/srcu.c +++ b/kernel/rcu/srcu.c @@ -263,7 +263,7 @@ EXPORT_SYMBOL_GPL(cleanup_srcu_struct); /* * Counts the new reader in the appropriate per-CPU element of the - * srcu_struct. Must be called from process context. + * srcu_struct. * Returns an index that must be passed to the matching srcu_read_unlock(). */ int __srcu_read_lock(struct srcu_struct *sp) @@ -271,7 +271,7 @@ int __srcu_read_lock(struct srcu_struct *sp) int idx; idx = READ_ONCE(sp->completed) & 0x1; - __this_cpu_inc(sp->per_cpu_ref->lock_count[idx]); + this_cpu_inc(sp->per_cpu_ref->lock_count[idx]); smp_mb(); /* B */ /* Avoid leaking the critical section. */ return idx; } @@ -281,7 +281,6 @@ EXPORT_SYMBOL_GPL(__srcu_read_lock); * Removes the count for the old reader from the appropriate per-CPU * element of the srcu_struct. Note that this may well be a different * CPU than that which was incremented by the corresponding srcu_read_lock(). - * Must be called from process context. */ void __srcu_read_unlock(struct srcu_struct *sp, int idx) { diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 36e1f82faed1..32798eb14853 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -97,8 +97,9 @@ EXPORT_SYMBOL_GPL(cleanup_srcu_struct); /* * Counts the new reader in the appropriate per-CPU element of the - * srcu_struct. Must be called from process context. - * Returns an index that must be passed to the matching srcu_read_unlock(). + * srcu_struct. Can be invoked from irq/bh handlers, but the matching + * __srcu_read_unlock() must be in the same handler instance. Returns an + * index that must be passed to the matching srcu_read_unlock(). */ int __srcu_read_lock(struct srcu_struct *sp) { @@ -112,7 +113,7 @@ EXPORT_SYMBOL_GPL(__srcu_read_lock); /* * Removes the count for the old reader from the appropriate element of - * the srcu_struct. Must be called from process context. + * the srcu_struct. */ void __srcu_read_unlock(struct srcu_struct *sp, int idx) { diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 3ae8474557df..157654fa436a 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -357,7 +357,7 @@ EXPORT_SYMBOL_GPL(cleanup_srcu_struct); /* * Counts the new reader in the appropriate per-CPU element of the - * srcu_struct. Must be called from process context. + * srcu_struct. * Returns an index that must be passed to the matching srcu_read_unlock(). */ int __srcu_read_lock(struct srcu_struct *sp) @@ -365,7 +365,7 @@ int __srcu_read_lock(struct srcu_struct *sp) int idx; idx = READ_ONCE(sp->srcu_idx) & 0x1; - __this_cpu_inc(sp->sda->srcu_lock_count[idx]); + this_cpu_inc(sp->sda->srcu_lock_count[idx]); smp_mb(); /* B */ /* Avoid leaking the critical section. */ return idx; } @@ -375,7 +375,6 @@ EXPORT_SYMBOL_GPL(__srcu_read_lock); * Removes the count for the old reader from the appropriate per-CPU * element of the srcu_struct. Note that this may well be a different * CPU than that which was incremented by the corresponding srcu_read_lock(). - * Must be called from process context. */ void __srcu_read_unlock(struct srcu_struct *sp, int idx) { |