Linus,
Please pull the latest rcu-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
rcu-urgent-for-linus
# HEAD: 8affb06737ae565722764c2b309eb0e892538344 Merge branch 'rcu/urgent'
of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into
rcu/urgent
Fix an SRCU bug affecting KVM IRQ injection.
Thanks,
Ingo
------------------>
Paolo Bonzini (2):
srcu: Allow use of Tiny/Tree SRCU from both process and interrupt context
srcu: Allow use of Classic SRCU from both process and interrupt context
include/linux/srcu.h | 2 --
kernel/rcu/srcu.c | 5 ++---
kernel/rcu/srcutiny.c | 7 ++++---
kernel/rcu/srcutree.c | 5 ++---
4 files changed, 8 insertions(+), 11 deletions(-)
diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index 167ad8831aaf..4c1d5f7e62c4 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -172,9 +172,7 @@ static inline int srcu_read_lock(struct srcu_struct *sp)
__acquires(sp)
{
int retval;
- preempt_disable();
retval = __srcu_read_lock(sp);
- preempt_enable();
rcu_lock_acquire(&(sp)->dep_map);
return retval;
}
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)
{
