[PATCH tip/core/rcu 12/17] rcu: Rename *_kfree_callback/*_kfree_rcu_offset/kfree_call_*

paulmck
2020-06-24T20:13:10Z

From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>

The following changes are introduced:

1. Rename rcu_invoke_kfree_callback() to rcu_invoke_kvfree_callback(),
as well as the associated trace events, so the rcu_kfree_callback(),
becomes rcu_kvfree_callback(). The reason is to be aligned with kvfree()
notation.

2. Rename __is_kfree_rcu_offset to __is_kvfree_rcu_offset. All RCU
paths use kvfree() now instead of kfree(), thus rename it.

3. Rename kfree_call_rcu() to the kvfree_call_rcu(). The reason is,
it is capable of freeing vmalloc() memory now. Do the same with
__kfree_rcu() macro, it becomes __kvfree_rcu(), the goal is the
same.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Co-developed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
include/linux/rcupdate.h | 14 +++++++-------
include/linux/rcutiny.h | 2 +-
include/linux/rcutree.h | 2 +-
include/trace/events/rcu.h | 8 ++++----
kernel/rcu/tiny.c | 4 ++--
kernel/rcu/tree.c | 16 ++++++++--------
6 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 659cbfa..b344fc8 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -828,17 +828,17 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)

/*
* Does the specified offset indicate that the corresponding rcu_head
- * structure can be handled by kfree_rcu()?
+ * structure can be handled by kvfree_rcu()?
*/
-#define __is_kfree_rcu_offset(offset) ((offset) < 4096)
+#define __is_kvfree_rcu_offset(offset) ((offset) < 4096)

/*
* Helper macro for kfree_rcu() to prevent argument-expansion eyestrain.
*/
-#define __kfree_rcu(head, offset) \
+#define __kvfree_rcu(head, offset) \
do { \
- BUILD_BUG_ON(!__is_kfree_rcu_offset(offset)); \
- kfree_call_rcu(head, (rcu_callback_t)(unsigned long)(offset)); \
+ BUILD_BUG_ON(!__is_kvfree_rcu_offset(offset)); \
+ kvfree_call_rcu(head, (rcu_callback_t)(unsigned long)(offset)); \
} while (0)

/**
@@ -857,7 +857,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
* Because the functions are not allowed in the low-order 4096 bytes of
* kernel virtual memory, offsets up to 4095 bytes can be accommodated.
* If the offset is larger than 4095 bytes, a compile-time error will
- * be generated in __kfree_rcu(). If this error is triggered, you can
+ * be generated in __kvfree_rcu(). If this error is triggered, you can
* either fall back to use of call_rcu() or rearrange the structure to
* position the rcu_head structure into the first 4096 bytes.
*
@@ -872,7 +872,7 @@ do { \
typeof (ptr) ___p = (ptr); \
\
if (___p) \
- __kfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \
+ __kvfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \
} while (0)

/*
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 8512cae..fb2eb39 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -34,7 +34,7 @@ static inline void synchronize_rcu_expedited(void)
synchronize_rcu();
}

-static inline void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
+static inline void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
{
call_rcu(head, func);
}
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index d5cc9d67..d2f4064 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -33,7 +33,7 @@ static inline void rcu_virt_note_context_switch(int cpu)
}

void synchronize_rcu_expedited(void);
-void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func);
+void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func);

void rcu_barrier(void);
bool rcu_eqs_special_set(int cpu);
diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index f9a7811..0ee93d0 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -506,13 +506,13 @@ TRACE_EVENT_RCU(rcu_callback,

/*
* Tracepoint for the registration of a single RCU callback of the special
- * kfree() form. The first argument is the RCU type, the second argument
+ * kvfree() form. The first argument is the RCU type, the second argument
* is a pointer to the RCU callback, the third argument is the offset
* of the callback within the enclosing RCU-protected data structure,
* the fourth argument is the number of lazy callbacks queued, and the
* fifth argument is the total number of callbacks queued.
*/
-TRACE_EVENT_RCU(rcu_kfree_callback,
+TRACE_EVENT_RCU(rcu_kvfree_callback,

TP_PROTO(const char *rcuname, struct rcu_head *rhp, unsigned long offset,
long qlen),
@@ -596,12 +596,12 @@ TRACE_EVENT_RCU(rcu_invoke_callback,

/*
* Tracepoint for the invocation of a single RCU callback of the special
- * kfree() form. The first argument is the RCU flavor, the second
+ * kvfree() form. The first argument is the RCU flavor, the second
* argument is a pointer to the RCU callback, and the third argument
* is the offset of the callback within the enclosing RCU-protected
* data structure.
*/
-TRACE_EVENT_RCU(rcu_invoke_kfree_callback,
+TRACE_EVENT_RCU(rcu_invoke_kvfree_callback,

TP_PROTO(const char *rcuname, struct rcu_head *rhp, unsigned long offset),

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 4b99f7b8..aa897c3 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -85,8 +85,8 @@ static inline bool rcu_reclaim_tiny(struct rcu_head *head)
unsigned long offset = (unsigned long)head->func;

rcu_lock_acquire(&rcu_callback_map);
- if (__is_kfree_rcu_offset(offset)) {
- trace_rcu_invoke_kfree_callback("", head, offset);
+ if (__is_kvfree_rcu_offset(offset)) {
+ trace_rcu_invoke_kvfree_callback("", head, offset);
kvfree((void *)head - offset);
rcu_lock_release(&rcu_callback_map);
return true;
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 659f67b..07fb5a36 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2887,8 +2887,8 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func)
return; // Enqueued onto ->nocb_bypass, so just leave.
// If no-CBs CPU gets here, rcu_nocb_try_bypass() acquired ->nocb_lock.
rcu_segcblist_enqueue(&rdp->cblist, head);
- if (__is_kfree_rcu_offset((unsigned long)func))
- trace_rcu_kfree_callback(rcu_state.name, head,
+ if (__is_kvfree_rcu_offset((unsigned long)func))
+ trace_rcu_kvfree_callback(rcu_state.name, head,
(unsigned long)func,
rcu_segcblist_n_cbs(&rdp->cblist));
else
@@ -3128,7 +3128,7 @@ static void kfree_rcu_work(struct work_struct *work)
bkvhead[i]->records);
} else { // vmalloc() / vfree().
for (j = 0; j < bkvhead[i]->nr_records; j++) {
- trace_rcu_invoke_kfree_callback(
+ trace_rcu_invoke_kvfree_callback(
rcu_state.name,
bkvhead[i]->records[j], 0);

@@ -3161,9 +3161,9 @@ static void kfree_rcu_work(struct work_struct *work)
next = head->next;
debug_rcu_head_unqueue((struct rcu_head *)ptr);
rcu_lock_acquire(&rcu_callback_map);
- trace_rcu_invoke_kfree_callback(rcu_state.name, head, offset);
+ trace_rcu_invoke_kvfree_callback(rcu_state.name, head, offset);

- if (!WARN_ON_ONCE(!__is_kfree_rcu_offset(offset)))
+ if (!WARN_ON_ONCE(!__is_kvfree_rcu_offset(offset)))
kvfree(ptr);

rcu_lock_release(&rcu_callback_map);
@@ -3326,12 +3326,12 @@ kvfree_call_rcu_add_ptr_to_bulk(struct kfree_rcu_cpu *krcp, void *ptr)
* one, that is used only when the main path can not be maintained temporary,
* due to memory pressure.
*
- * Each kfree_call_rcu() request is added to a batch. The batch will be drained
+ * Each kvfree_call_rcu() request is added to a batch. The batch will be drained
* every KFREE_DRAIN_JIFFIES number of jiffies. All the objects in the batch will
* be free'd in workqueue context. This allows us to: batch requests together to
* reduce the number of grace periods during heavy kfree_rcu()/kvfree_rcu() load.
*/
-void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
+void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
{
unsigned long flags;
struct kfree_rcu_cpu *krcp;
@@ -3370,7 +3370,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
unlock_return:
krc_this_cpu_unlock(krcp, flags);
}
-EXPORT_SYMBOL_GPL(kfree_call_rcu);
+EXPORT_SYMBOL_GPL(kvfree_call_rcu);

static unsigned long
kfree_rcu_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
--
2.9.5