* [PATCH 1/3] mm/mmu_notifier: Rename struct mmu_notifier_mm to mmu_notifier_subscriptions
2020-01-16 16:39 [PATCH 0/3] Rename variables in mmu_notifier.c Jason Gunthorpe
@ 2020-01-16 16:39 ` Jason Gunthorpe
2020-01-16 16:39 ` [PATCH 2/3] mm/mmu_notifiers: Use 'subscription' as the variable name for mmu_notifier Jason Gunthorpe
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Jason Gunthorpe @ 2020-01-16 16:39 UTC (permalink / raw)
To: linux-mm, Daniel Vetter, Jerome Glisse, Ralph Campbell
Cc: linux-rdma, Jason Gunthorpe
From: Jason Gunthorpe <jgg@mellanox.com>
The name mmu_notifier_mm implies that the thing is a mm_struct pointer,
and is difficult to abbreviate. The struct is actually holding the
interval tree and hlist containing the notifiers subscribed to a mm.
Use 'subscriptions' as the variable name for this struct instead of the
really terrible and misleading 'mmn_mm'.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---
include/linux/mm_types.h | 2 +-
include/linux/mmu_notifier.h | 18 +-
kernel/fork.c | 4 +-
mm/debug.c | 4 +-
mm/mmu_notifier.c | 326 ++++++++++++++++++-----------------
5 files changed, 184 insertions(+), 170 deletions(-)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 270aa8fd2800b4..e87bb864bdb29a 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -490,7 +490,7 @@ struct mm_struct {
/* store ref to file /proc/<pid>/exe symlink points to */
struct file __rcu *exe_file;
#ifdef CONFIG_MMU_NOTIFIER
- struct mmu_notifier_mm *mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *notifier_subscriptions;
#endif
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
pgtable_t pmd_huge_pte; /* protected by page_table_lock */
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 9e6caa8ecd1938..a302925fbc6177 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -8,7 +8,7 @@
#include <linux/srcu.h>
#include <linux/interval_tree.h>
-struct mmu_notifier_mm;
+struct mmu_notifier_subscriptions;
struct mmu_notifier;
struct mmu_notifier_range;
struct mmu_interval_notifier;
@@ -265,7 +265,7 @@ struct mmu_notifier_range {
static inline int mm_has_notifiers(struct mm_struct *mm)
{
- return unlikely(mm->mmu_notifier_mm);
+ return unlikely(mm->notifier_subscriptions);
}
struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
@@ -364,7 +364,7 @@ static inline bool mmu_interval_check_retry(struct mmu_interval_notifier *mni,
return READ_ONCE(mni->invalidate_seq) != seq;
}
-extern void __mmu_notifier_mm_destroy(struct mm_struct *mm);
+extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm);
extern void __mmu_notifier_release(struct mm_struct *mm);
extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
unsigned long start,
@@ -480,15 +480,15 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
__mmu_notifier_invalidate_range(mm, start, end);
}
-static inline void mmu_notifier_mm_init(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
{
- mm->mmu_notifier_mm = NULL;
+ mm->notifier_subscriptions = NULL;
}
-static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_mm_destroy(mm);
+ __mmu_notifier_subscriptions_destroy(mm);
}
@@ -692,11 +692,11 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
{
}
-static inline void mmu_notifier_mm_init(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
{
}
-static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
{
}
diff --git a/kernel/fork.c b/kernel/fork.c
index 2508a4f238a3f3..047865086cdf74 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -692,7 +692,7 @@ void __mmdrop(struct mm_struct *mm)
WARN_ON_ONCE(mm == current->active_mm);
mm_free_pgd(mm);
destroy_context(mm);
- mmu_notifier_mm_destroy(mm);
+ mmu_notifier_subscriptions_destroy(mm);
check_mm(mm);
put_user_ns(mm->user_ns);
free_mm(mm);
@@ -1025,7 +1025,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
mm_init_aio(mm);
mm_init_owner(mm, p);
RCU_INIT_POINTER(mm->exe_file, NULL);
- mmu_notifier_mm_init(mm);
+ mmu_notifier_subscriptions_init(mm);
init_tlb_flush_pending(mm);
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
mm->pmd_huge_pte = NULL;
diff --git a/mm/debug.c b/mm/debug.c
index 0461df1207cb09..74ee73cf7079a5 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -153,7 +153,7 @@ void dump_mm(const struct mm_struct *mm)
#endif
"exe_file %px\n"
#ifdef CONFIG_MMU_NOTIFIER
- "mmu_notifier_mm %px\n"
+ "notifier_subscriptions %px\n"
#endif
#ifdef CONFIG_NUMA_BALANCING
"numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
@@ -185,7 +185,7 @@ void dump_mm(const struct mm_struct *mm)
#endif
mm->exe_file,
#ifdef CONFIG_MMU_NOTIFIER
- mm->mmu_notifier_mm,
+ mm->notifier_subscriptions,
#endif
#ifdef CONFIG_NUMA_BALANCING
mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index f76ea05b1cb011..a409abfb9f2652 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -29,12 +29,12 @@ struct lockdep_map __mmu_notifier_invalidate_range_start_map = {
#endif
/*
- * The mmu notifier_mm structure is allocated and installed in
- * mm->mmu_notifier_mm inside the mm_take_all_locks() protected
+ * The mmu_notifier_subscriptions structure is allocated and installed in
+ * mm->notifier_subscriptions inside the mm_take_all_locks() protected
* critical section and it's released only when mm_count reaches zero
* in mmdrop().
*/
-struct mmu_notifier_mm {
+struct mmu_notifier_subscriptions {
/* all mmu notifiers registered in this mm are queued in this list */
struct hlist_head list;
bool has_itree;
@@ -65,17 +65,17 @@ struct mmu_notifier_mm {
*
* The write side has two states, fully excluded:
* - mm->active_invalidate_ranges != 0
- * - mnn->invalidate_seq & 1 == True (odd)
+ * - subscriptions->invalidate_seq & 1 == True (odd)
* - some range on the mm_struct is being invalidated
* - the itree is not allowed to change
*
* And partially excluded:
* - mm->active_invalidate_ranges != 0
- * - mnn->invalidate_seq & 1 == False (even)
+ * - subscriptions->invalidate_seq & 1 == False (even)
* - some range on the mm_struct is being invalidated
* - the itree is allowed to change
*
- * Operations on mmu_notifier_mm->invalidate_seq (under spinlock):
+ * Operations on notifier_subscriptions->invalidate_seq (under spinlock):
* seq |= 1 # Begin writing
* seq++ # Release the writing state
* seq & 1 # True if a writer exists
@@ -83,32 +83,33 @@ struct mmu_notifier_mm {
* The later state avoids some expensive work on inv_end in the common case of
* no mni monitoring the VA.
*/
-static bool mn_itree_is_invalidating(struct mmu_notifier_mm *mmn_mm)
+static bool
+mn_itree_is_invalidating(struct mmu_notifier_subscriptions *subscriptions)
{
- lockdep_assert_held(&mmn_mm->lock);
- return mmn_mm->invalidate_seq & 1;
+ lockdep_assert_held(&subscriptions->lock);
+ return subscriptions->invalidate_seq & 1;
}
static struct mmu_interval_notifier *
-mn_itree_inv_start_range(struct mmu_notifier_mm *mmn_mm,
+mn_itree_inv_start_range(struct mmu_notifier_subscriptions *subscriptions,
const struct mmu_notifier_range *range,
unsigned long *seq)
{
struct interval_tree_node *node;
struct mmu_interval_notifier *res = NULL;
- spin_lock(&mmn_mm->lock);
- mmn_mm->active_invalidate_ranges++;
- node = interval_tree_iter_first(&mmn_mm->itree, range->start,
+ spin_lock(&subscriptions->lock);
+ subscriptions->active_invalidate_ranges++;
+ node = interval_tree_iter_first(&subscriptions->itree, range->start,
range->end - 1);
if (node) {
- mmn_mm->invalidate_seq |= 1;
+ subscriptions->invalidate_seq |= 1;
res = container_of(node, struct mmu_interval_notifier,
interval_tree);
}
- *seq = mmn_mm->invalidate_seq;
- spin_unlock(&mmn_mm->lock);
+ *seq = subscriptions->invalidate_seq;
+ spin_unlock(&subscriptions->lock);
return res;
}
@@ -125,20 +126,20 @@ mn_itree_inv_next(struct mmu_interval_notifier *mni,
return container_of(node, struct mmu_interval_notifier, interval_tree);
}
-static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
+static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
{
struct mmu_interval_notifier *mni;
struct hlist_node *next;
- spin_lock(&mmn_mm->lock);
- if (--mmn_mm->active_invalidate_ranges ||
- !mn_itree_is_invalidating(mmn_mm)) {
- spin_unlock(&mmn_mm->lock);
+ spin_lock(&subscriptions->lock);
+ if (--subscriptions->active_invalidate_ranges ||
+ !mn_itree_is_invalidating(subscriptions)) {
+ spin_unlock(&subscriptions->lock);
return;
}
/* Make invalidate_seq even */
- mmn_mm->invalidate_seq++;
+ subscriptions->invalidate_seq++;
/*
* The inv_end incorporates a deferred mechanism like rtnl_unlock().
@@ -146,19 +147,19 @@ static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
* they are progressed. This arrangement for tree updates is used to
* avoid using a blocking lock during invalidate_range_start.
*/
- hlist_for_each_entry_safe(mni, next, &mmn_mm->deferred_list,
+ hlist_for_each_entry_safe(mni, next, &subscriptions->deferred_list,
deferred_item) {
if (RB_EMPTY_NODE(&mni->interval_tree.rb))
interval_tree_insert(&mni->interval_tree,
- &mmn_mm->itree);
+ &subscriptions->itree);
else
interval_tree_remove(&mni->interval_tree,
- &mmn_mm->itree);
+ &subscriptions->itree);
hlist_del(&mni->deferred_item);
}
- spin_unlock(&mmn_mm->lock);
+ spin_unlock(&subscriptions->lock);
- wake_up_all(&mmn_mm->wq);
+ wake_up_all(&subscriptions->wq);
}
/**
@@ -182,7 +183,8 @@ static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
*/
unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
{
- struct mmu_notifier_mm *mmn_mm = mni->mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ mni->mm->notifier_subscriptions;
unsigned long seq;
bool is_invalidating;
@@ -190,17 +192,18 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
* If the mni has a different seq value under the user_lock than we
* started with then it has collided.
*
- * If the mni currently has the same seq value as the mmn_mm seq, then
- * it is currently between invalidate_start/end and is colliding.
+ * If the mni currently has the same seq value as the subscriptions
+ * seq, then it is currently between invalidate_start/end and is
+ * colliding.
*
* The locking looks broadly like this:
* mn_tree_invalidate_start(): mmu_interval_read_begin():
* spin_lock
* seq = READ_ONCE(mni->invalidate_seq);
- * seq == mmn_mm->invalidate_seq
+ * seq == subs->invalidate_seq
* spin_unlock
* spin_lock
- * seq = ++mmn_mm->invalidate_seq
+ * seq = ++subscriptions->invalidate_seq
* spin_unlock
* op->invalidate_range():
* user_lock
@@ -212,7 +215,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
*
* mn_itree_inv_end():
* spin_lock
- * seq = ++mmn_mm->invalidate_seq
+ * seq = ++subscriptions->invalidate_seq
* spin_unlock
*
* user_lock
@@ -224,24 +227,24 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
* eventual mmu_interval_read_retry(), which provides a barrier via the
* user_lock.
*/
- spin_lock(&mmn_mm->lock);
+ spin_lock(&subscriptions->lock);
/* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
seq = READ_ONCE(mni->invalidate_seq);
- is_invalidating = seq == mmn_mm->invalidate_seq;
- spin_unlock(&mmn_mm->lock);
+ is_invalidating = seq == subscriptions->invalidate_seq;
+ spin_unlock(&subscriptions->lock);
/*
* mni->invalidate_seq must always be set to an odd value via
* mmu_interval_set_seq() using the provided cur_seq from
* mn_itree_inv_start_range(). This ensures that if seq does wrap we
* will always clear the below sleep in some reasonable time as
- * mmn_mm->invalidate_seq is even in the idle state.
+ * subscriptions->invalidate_seq is even in the idle state.
*/
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
if (is_invalidating)
- wait_event(mmn_mm->wq,
- READ_ONCE(mmn_mm->invalidate_seq) != seq);
+ wait_event(subscriptions->wq,
+ READ_ONCE(subscriptions->invalidate_seq) != seq);
/*
* Notice that mmu_interval_read_retry() can already be true at this
@@ -253,7 +256,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
}
EXPORT_SYMBOL_GPL(mmu_interval_read_begin);
-static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
+static void mn_itree_release(struct mmu_notifier_subscriptions *subscriptions,
struct mm_struct *mm)
{
struct mmu_notifier_range range = {
@@ -267,13 +270,13 @@ static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
unsigned long cur_seq;
bool ret;
- for (mni = mn_itree_inv_start_range(mmn_mm, &range, &cur_seq); mni;
- mni = mn_itree_inv_next(mni, &range)) {
+ for (mni = mn_itree_inv_start_range(subscriptions, &range, &cur_seq);
+ mni; mni = mn_itree_inv_next(mni, &range)) {
ret = mni->ops->invalidate(mni, &range, cur_seq);
WARN_ON(!ret);
}
- mn_itree_inv_end(mmn_mm);
+ mn_itree_inv_end(subscriptions);
}
/*
@@ -283,12 +286,12 @@ static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
* in parallel despite there being no task using this mm any more,
* through the vmas outside of the exit_mmap context, such as with
* vmtruncate. This serializes against mmu_notifier_unregister with
- * the mmu_notifier_mm->lock in addition to SRCU and it serializes
- * against the other mmu notifiers with SRCU. struct mmu_notifier_mm
+ * the notifier_subscriptions->lock in addition to SRCU and it serializes
+ * against the other mmu notifiers with SRCU. struct mmu_notifier_subscriptions
* can't go away from under us as exit_mmap holds an mm_count pin
* itself.
*/
-static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
+static void mn_hlist_release(struct mmu_notifier_subscriptions *subscriptions,
struct mm_struct *mm)
{
struct mmu_notifier *mn;
@@ -299,7 +302,7 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
* ->release returns.
*/
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist)
+ hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist)
/*
* If ->release runs before mmu_notifier_unregister it must be
* handled, as it's the only way for the driver to flush all
@@ -309,9 +312,9 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
if (mn->ops->release)
mn->ops->release(mn, mm);
- spin_lock(&mmn_mm->lock);
- while (unlikely(!hlist_empty(&mmn_mm->list))) {
- mn = hlist_entry(mmn_mm->list.first, struct mmu_notifier,
+ spin_lock(&subscriptions->lock);
+ while (unlikely(!hlist_empty(&subscriptions->list))) {
+ mn = hlist_entry(subscriptions->list.first, struct mmu_notifier,
hlist);
/*
* We arrived before mmu_notifier_unregister so
@@ -321,7 +324,7 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
*/
hlist_del_init_rcu(&mn->hlist);
}
- spin_unlock(&mmn_mm->lock);
+ spin_unlock(&subscriptions->lock);
srcu_read_unlock(&srcu, id);
/*
@@ -330,21 +333,22 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
* until the ->release method returns, if it was invoked by
* mmu_notifier_unregister.
*
- * The mmu_notifier_mm can't go away from under us because one mm_count
- * is held by exit_mmap.
+ * The notifier_subscriptions can't go away from under us because
+ * one mm_count is held by exit_mmap.
*/
synchronize_srcu(&srcu);
}
void __mmu_notifier_release(struct mm_struct *mm)
{
- struct mmu_notifier_mm *mmn_mm = mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ mm->notifier_subscriptions;
- if (mmn_mm->has_itree)
- mn_itree_release(mmn_mm, mm);
+ if (subscriptions->has_itree)
+ mn_itree_release(subscriptions, mm);
- if (!hlist_empty(&mmn_mm->list))
- mn_hlist_release(mmn_mm, mm);
+ if (!hlist_empty(&subscriptions->list))
+ mn_hlist_release(subscriptions, mm);
}
/*
@@ -360,7 +364,7 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
int young = 0, id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
if (mn->ops->clear_flush_young)
young |= mn->ops->clear_flush_young(mn, mm, start, end);
}
@@ -377,7 +381,7 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
int young = 0, id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
if (mn->ops->clear_young)
young |= mn->ops->clear_young(mn, mm, start, end);
}
@@ -393,7 +397,7 @@ int __mmu_notifier_test_young(struct mm_struct *mm,
int young = 0, id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
if (mn->ops->test_young) {
young = mn->ops->test_young(mn, mm, address);
if (young)
@@ -412,21 +416,22 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list,
+ hlist) {
if (mn->ops->change_pte)
mn->ops->change_pte(mn, mm, address, pte);
}
srcu_read_unlock(&srcu, id);
}
-static int mn_itree_invalidate(struct mmu_notifier_mm *mmn_mm,
+static int mn_itree_invalidate(struct mmu_notifier_subscriptions *subscriptions,
const struct mmu_notifier_range *range)
{
struct mmu_interval_notifier *mni;
unsigned long cur_seq;
- for (mni = mn_itree_inv_start_range(mmn_mm, range, &cur_seq); mni;
- mni = mn_itree_inv_next(mni, range)) {
+ for (mni = mn_itree_inv_start_range(subscriptions, range, &cur_seq);
+ mni; mni = mn_itree_inv_next(mni, range)) {
bool ret;
ret = mni->ops->invalidate(mni, range, cur_seq);
@@ -443,19 +448,20 @@ static int mn_itree_invalidate(struct mmu_notifier_mm *mmn_mm,
* On -EAGAIN the non-blocking caller is not allowed to call
* invalidate_range_end()
*/
- mn_itree_inv_end(mmn_mm);
+ mn_itree_inv_end(subscriptions);
return -EAGAIN;
}
-static int mn_hlist_invalidate_range_start(struct mmu_notifier_mm *mmn_mm,
- struct mmu_notifier_range *range)
+static int mn_hlist_invalidate_range_start(
+ struct mmu_notifier_subscriptions *subscriptions,
+ struct mmu_notifier_range *range)
{
struct mmu_notifier *mn;
int ret = 0;
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist) {
if (mn->ops->invalidate_range_start) {
int _ret;
@@ -481,28 +487,29 @@ static int mn_hlist_invalidate_range_start(struct mmu_notifier_mm *mmn_mm,
int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
{
- struct mmu_notifier_mm *mmn_mm = range->mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ range->mm->notifier_subscriptions;
int ret;
- if (mmn_mm->has_itree) {
- ret = mn_itree_invalidate(mmn_mm, range);
+ if (subscriptions->has_itree) {
+ ret = mn_itree_invalidate(subscriptions, range);
if (ret)
return ret;
}
- if (!hlist_empty(&mmn_mm->list))
- return mn_hlist_invalidate_range_start(mmn_mm, range);
+ if (!hlist_empty(&subscriptions->list))
+ return mn_hlist_invalidate_range_start(subscriptions, range);
return 0;
}
-static void mn_hlist_invalidate_end(struct mmu_notifier_mm *mmn_mm,
- struct mmu_notifier_range *range,
- bool only_end)
+static void
+mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions,
+ struct mmu_notifier_range *range, bool only_end)
{
struct mmu_notifier *mn;
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist) {
/*
* Call invalidate_range here too to avoid the need for the
* subsystem of having to register an invalidate_range_end
@@ -534,14 +541,15 @@ static void mn_hlist_invalidate_end(struct mmu_notifier_mm *mmn_mm,
void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range,
bool only_end)
{
- struct mmu_notifier_mm *mmn_mm = range->mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ range->mm->notifier_subscriptions;
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
- if (mmn_mm->has_itree)
- mn_itree_inv_end(mmn_mm);
+ if (subscriptions->has_itree)
+ mn_itree_inv_end(subscriptions);
- if (!hlist_empty(&mmn_mm->list))
- mn_hlist_invalidate_end(mmn_mm, range, only_end);
+ if (!hlist_empty(&subscriptions->list))
+ mn_hlist_invalidate_end(subscriptions, range, only_end);
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
}
@@ -552,7 +560,7 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm,
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
if (mn->ops->invalidate_range)
mn->ops->invalidate_range(mn, mm, start, end);
}
@@ -566,7 +574,7 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm,
*/
int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
{
- struct mmu_notifier_mm *mmu_notifier_mm = NULL;
+ struct mmu_notifier_subscriptions *subscriptions = NULL;
int ret;
lockdep_assert_held_write(&mm->mmap_sem);
@@ -579,23 +587,23 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
fs_reclaim_release(GFP_KERNEL);
}
- if (!mm->mmu_notifier_mm) {
+ if (!mm->notifier_subscriptions) {
/*
* kmalloc cannot be called under mm_take_all_locks(), but we
- * know that mm->mmu_notifier_mm can't change while we hold
- * the write side of the mmap_sem.
+ * know that mm->notifier_subscriptions can't change while we
+ * hold the write side of the mmap_sem.
*/
- mmu_notifier_mm =
- kzalloc(sizeof(struct mmu_notifier_mm), GFP_KERNEL);
- if (!mmu_notifier_mm)
+ subscriptions = kzalloc(
+ sizeof(struct mmu_notifier_subscriptions), GFP_KERNEL);
+ if (!subscriptions)
return -ENOMEM;
- INIT_HLIST_HEAD(&mmu_notifier_mm->list);
- spin_lock_init(&mmu_notifier_mm->lock);
- mmu_notifier_mm->invalidate_seq = 2;
- mmu_notifier_mm->itree = RB_ROOT_CACHED;
- init_waitqueue_head(&mmu_notifier_mm->wq);
- INIT_HLIST_HEAD(&mmu_notifier_mm->deferred_list);
+ INIT_HLIST_HEAD(&subscriptions->list);
+ spin_lock_init(&subscriptions->lock);
+ subscriptions->invalidate_seq = 2;
+ subscriptions->itree = RB_ROOT_CACHED;
+ init_waitqueue_head(&subscriptions->wq);
+ INIT_HLIST_HEAD(&subscriptions->deferred_list);
}
ret = mm_take_all_locks(mm);
@@ -610,15 +618,16 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
* We can't race against any other mmu notifier method either
* thanks to mm_take_all_locks().
*
- * release semantics on the initialization of the mmu_notifier_mm's
- * contents are provided for unlocked readers. acquire can only be
- * used while holding the mmgrab or mmget, and is safe because once
- * created the mmu_notififer_mm is not freed until the mm is
- * destroyed. As above, users holding the mmap_sem or one of the
+ * release semantics on the initialization of the
+ * mmu_notifier_subscriptions's contents are provided for unlocked
+ * readers. acquire can only be used while holding the mmgrab or
+ * mmget, and is safe because once created the
+ * mmu_notifier_subscriptions is not freed until the mm is destroyed.
+ * As above, users holding the mmap_sem or one of the
* mm_take_all_locks() do not need to use acquire semantics.
*/
- if (mmu_notifier_mm)
- smp_store_release(&mm->mmu_notifier_mm, mmu_notifier_mm);
+ if (subscriptions)
+ smp_store_release(&mm->notifier_subscriptions, subscriptions);
if (mn) {
/* Pairs with the mmdrop in mmu_notifier_unregister_* */
@@ -626,18 +635,19 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
mn->mm = mm;
mn->users = 1;
- spin_lock(&mm->mmu_notifier_mm->lock);
- hlist_add_head_rcu(&mn->hlist, &mm->mmu_notifier_mm->list);
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_lock(&mm->notifier_subscriptions->lock);
+ hlist_add_head_rcu(&mn->hlist,
+ &mm->notifier_subscriptions->list);
+ spin_unlock(&mm->notifier_subscriptions->lock);
} else
- mm->mmu_notifier_mm->has_itree = true;
+ mm->notifier_subscriptions->has_itree = true;
mm_drop_all_locks(mm);
BUG_ON(atomic_read(&mm->mm_users) <= 0);
return 0;
out_clean:
- kfree(mmu_notifier_mm);
+ kfree(subscriptions);
return ret;
}
EXPORT_SYMBOL_GPL(__mmu_notifier_register);
@@ -677,8 +687,9 @@ find_get_mmu_notifier(struct mm_struct *mm, const struct mmu_notifier_ops *ops)
{
struct mmu_notifier *mn;
- spin_lock(&mm->mmu_notifier_mm->lock);
- hlist_for_each_entry_rcu (mn, &mm->mmu_notifier_mm->list, hlist) {
+ spin_lock(&mm->notifier_subscriptions->lock);
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list,
+ hlist) {
if (mn->ops != ops)
continue;
@@ -686,10 +697,10 @@ find_get_mmu_notifier(struct mm_struct *mm, const struct mmu_notifier_ops *ops)
mn->users++;
else
mn = ERR_PTR(-EOVERFLOW);
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
return mn;
}
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
return NULL;
}
@@ -718,7 +729,7 @@ struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
lockdep_assert_held_write(&mm->mmap_sem);
- if (mm->mmu_notifier_mm) {
+ if (mm->notifier_subscriptions) {
mn = find_get_mmu_notifier(mm, ops);
if (mn)
return mn;
@@ -739,11 +750,11 @@ struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
EXPORT_SYMBOL_GPL(mmu_notifier_get_locked);
/* this is called after the last mmu_notifier_unregister() returned */
-void __mmu_notifier_mm_destroy(struct mm_struct *mm)
+void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
{
- BUG_ON(!hlist_empty(&mm->mmu_notifier_mm->list));
- kfree(mm->mmu_notifier_mm);
- mm->mmu_notifier_mm = LIST_POISON1; /* debug */
+ BUG_ON(!hlist_empty(&mm->notifier_subscriptions->list));
+ kfree(mm->notifier_subscriptions);
+ mm->notifier_subscriptions = LIST_POISON1; /* debug */
}
/*
@@ -776,13 +787,13 @@ void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm)
mn->ops->release(mn, mm);
srcu_read_unlock(&srcu, id);
- spin_lock(&mm->mmu_notifier_mm->lock);
+ spin_lock(&mm->notifier_subscriptions->lock);
/*
* Can not use list_del_rcu() since __mmu_notifier_release
* can delete it before we hold the lock.
*/
hlist_del_init_rcu(&mn->hlist);
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
}
/*
@@ -833,23 +844,23 @@ void mmu_notifier_put(struct mmu_notifier *mn)
{
struct mm_struct *mm = mn->mm;
- spin_lock(&mm->mmu_notifier_mm->lock);
+ spin_lock(&mm->notifier_subscriptions->lock);
if (WARN_ON(!mn->users) || --mn->users)
goto out_unlock;
hlist_del_init_rcu(&mn->hlist);
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
call_srcu(&srcu, &mn->rcu, mmu_notifier_free_rcu);
return;
out_unlock:
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
}
EXPORT_SYMBOL_GPL(mmu_notifier_put);
static int __mmu_interval_notifier_insert(
struct mmu_interval_notifier *mni, struct mm_struct *mm,
- struct mmu_notifier_mm *mmn_mm, unsigned long start,
+ struct mmu_notifier_subscriptions *subscriptions, unsigned long start,
unsigned long length, const struct mmu_interval_notifier_ops *ops)
{
mni->mm = mm;
@@ -884,29 +895,30 @@ static int __mmu_interval_notifier_insert(
* In all cases the value for the mni->invalidate_seq should be
* odd, see mmu_interval_read_begin()
*/
- spin_lock(&mmn_mm->lock);
- if (mmn_mm->active_invalidate_ranges) {
- if (mn_itree_is_invalidating(mmn_mm))
+ spin_lock(&subscriptions->lock);
+ if (subscriptions->active_invalidate_ranges) {
+ if (mn_itree_is_invalidating(subscriptions))
hlist_add_head(&mni->deferred_item,
- &mmn_mm->deferred_list);
+ &subscriptions->deferred_list);
else {
- mmn_mm->invalidate_seq |= 1;
+ subscriptions->invalidate_seq |= 1;
interval_tree_insert(&mni->interval_tree,
- &mmn_mm->itree);
+ &subscriptions->itree);
}
- mni->invalidate_seq = mmn_mm->invalidate_seq;
+ mni->invalidate_seq = subscriptions->invalidate_seq;
} else {
- WARN_ON(mn_itree_is_invalidating(mmn_mm));
+ WARN_ON(mn_itree_is_invalidating(subscriptions));
/*
* The starting seq for a mni not under invalidation should be
* odd, not equal to the current invalidate_seq and
* invalidate_seq should not 'wrap' to the new seq any time
* soon.
*/
- mni->invalidate_seq = mmn_mm->invalidate_seq - 1;
- interval_tree_insert(&mni->interval_tree, &mmn_mm->itree);
+ mni->invalidate_seq = subscriptions->invalidate_seq - 1;
+ interval_tree_insert(&mni->interval_tree,
+ &subscriptions->itree);
}
- spin_unlock(&mmn_mm->lock);
+ spin_unlock(&subscriptions->lock);
return 0;
}
@@ -930,20 +942,20 @@ int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
unsigned long length,
const struct mmu_interval_notifier_ops *ops)
{
- struct mmu_notifier_mm *mmn_mm;
+ struct mmu_notifier_subscriptions *subscriptions;
int ret;
might_lock(&mm->mmap_sem);
- mmn_mm = smp_load_acquire(&mm->mmu_notifier_mm);
- if (!mmn_mm || !mmn_mm->has_itree) {
+ subscriptions = smp_load_acquire(&mm->notifier_subscriptions);
+ if (!subscriptions || !subscriptions->has_itree) {
ret = mmu_notifier_register(NULL, mm);
if (ret)
return ret;
- mmn_mm = mm->mmu_notifier_mm;
+ subscriptions = mm->notifier_subscriptions;
}
- return __mmu_interval_notifier_insert(mni, mm, mmn_mm, start, length,
- ops);
+ return __mmu_interval_notifier_insert(mni, mm, subscriptions, start,
+ length, ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert);
@@ -952,20 +964,20 @@ int mmu_interval_notifier_insert_locked(
unsigned long start, unsigned long length,
const struct mmu_interval_notifier_ops *ops)
{
- struct mmu_notifier_mm *mmn_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ mm->notifier_subscriptions;
int ret;
lockdep_assert_held_write(&mm->mmap_sem);
- mmn_mm = mm->mmu_notifier_mm;
- if (!mmn_mm || !mmn_mm->has_itree) {
+ if (!subscriptions || !subscriptions->has_itree) {
ret = __mmu_notifier_register(NULL, mm);
if (ret)
return ret;
- mmn_mm = mm->mmu_notifier_mm;
+ subscriptions = mm->notifier_subscriptions;
}
- return __mmu_interval_notifier_insert(mni, mm, mmn_mm, start, length,
- ops);
+ return __mmu_interval_notifier_insert(mni, mm, subscriptions, start,
+ length, ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked);
@@ -982,13 +994,14 @@ EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked);
void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
{
struct mm_struct *mm = mni->mm;
- struct mmu_notifier_mm *mmn_mm = mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ mm->notifier_subscriptions;
unsigned long seq = 0;
might_sleep();
- spin_lock(&mmn_mm->lock);
- if (mn_itree_is_invalidating(mmn_mm)) {
+ spin_lock(&subscriptions->lock);
+ if (mn_itree_is_invalidating(subscriptions)) {
/*
* remove is being called after insert put this on the
* deferred list, but before the deferred list was processed.
@@ -997,14 +1010,15 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
hlist_del(&mni->deferred_item);
} else {
hlist_add_head(&mni->deferred_item,
- &mmn_mm->deferred_list);
- seq = mmn_mm->invalidate_seq;
+ &subscriptions->deferred_list);
+ seq = subscriptions->invalidate_seq;
}
} else {
WARN_ON(RB_EMPTY_NODE(&mni->interval_tree.rb));
- interval_tree_remove(&mni->interval_tree, &mmn_mm->itree);
+ interval_tree_remove(&mni->interval_tree,
+ &subscriptions->itree);
}
- spin_unlock(&mmn_mm->lock);
+ spin_unlock(&subscriptions->lock);
/*
* The possible sleep on progress in the invalidation requires the
@@ -1013,8 +1027,8 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
if (seq)
- wait_event(mmn_mm->wq,
- READ_ONCE(mmn_mm->invalidate_seq) != seq);
+ wait_event(subscriptions->wq,
+ READ_ONCE(subscriptions->invalidate_seq) != seq);
/* pairs with mmgrab in mmu_interval_notifier_insert() */
mmdrop(mm);
--
2.24.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/3] mm/mmu_notifiers: Use 'subscription' as the variable name for mmu_notifier
2020-01-16 16:39 [PATCH 0/3] Rename variables in mmu_notifier.c Jason Gunthorpe
2020-01-16 16:39 ` [PATCH 1/3] mm/mmu_notifier: Rename struct mmu_notifier_mm to mmu_notifier_subscriptions Jason Gunthorpe
@ 2020-01-16 16:39 ` Jason Gunthorpe
2020-01-16 16:39 ` [PATCH 3/3] mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier Jason Gunthorpe
2020-01-27 20:52 ` [PATCH 0/3] Rename variables in mmu_notifier.c Jason Gunthorpe
3 siblings, 0 replies; 5+ messages in thread
From: Jason Gunthorpe @ 2020-01-16 16:39 UTC (permalink / raw)
To: linux-mm, Daniel Vetter, Jerome Glisse, Ralph Campbell
Cc: linux-rdma, Jason Gunthorpe
From: Jason Gunthorpe <jgg@mellanox.com>
The 'subscription' is placed on the 'notifier_subscriptions' list.
This eliminates the poor name 'mn' for this variable.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---
include/linux/mmu_notifier.h | 30 +++---
mm/mmu_notifier.c | 183 +++++++++++++++++++----------------
2 files changed, 117 insertions(+), 96 deletions(-)
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index a302925fbc6177..4342fa75dc24cd 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -73,7 +73,7 @@ struct mmu_notifier_ops {
* through the gart alias address, so leading to memory
* corruption.
*/
- void (*release)(struct mmu_notifier *mn,
+ void (*release)(struct mmu_notifier *subscription,
struct mm_struct *mm);
/*
@@ -85,7 +85,7 @@ struct mmu_notifier_ops {
* Start-end is necessary in case the secondary MMU is mapping the page
* at a smaller granularity than the primary MMU.
*/
- int (*clear_flush_young)(struct mmu_notifier *mn,
+ int (*clear_flush_young)(struct mmu_notifier *subscription,
struct mm_struct *mm,
unsigned long start,
unsigned long end);
@@ -95,7 +95,7 @@ struct mmu_notifier_ops {
* latter, it is supposed to test-and-clear the young/accessed bitflag
* in the secondary pte, but it may omit flushing the secondary tlb.
*/
- int (*clear_young)(struct mmu_notifier *mn,
+ int (*clear_young)(struct mmu_notifier *subscription,
struct mm_struct *mm,
unsigned long start,
unsigned long end);
@@ -106,7 +106,7 @@ struct mmu_notifier_ops {
* frequently used without actually clearing the flag or tearing
* down the secondary mapping on the page.
*/
- int (*test_young)(struct mmu_notifier *mn,
+ int (*test_young)(struct mmu_notifier *subscription,
struct mm_struct *mm,
unsigned long address);
@@ -114,7 +114,7 @@ struct mmu_notifier_ops {
* change_pte is called in cases that pte mapping to page is changed:
* for example, when ksm remaps pte to point to a new shared page.
*/
- void (*change_pte)(struct mmu_notifier *mn,
+ void (*change_pte)(struct mmu_notifier *subscription,
struct mm_struct *mm,
unsigned long address,
pte_t pte);
@@ -169,9 +169,9 @@ struct mmu_notifier_ops {
* invalidate_range_end.
*
*/
- int (*invalidate_range_start)(struct mmu_notifier *mn,
+ int (*invalidate_range_start)(struct mmu_notifier *subscription,
const struct mmu_notifier_range *range);
- void (*invalidate_range_end)(struct mmu_notifier *mn,
+ void (*invalidate_range_end)(struct mmu_notifier *subscription,
const struct mmu_notifier_range *range);
/*
@@ -192,8 +192,10 @@ struct mmu_notifier_ops {
* of what was passed to invalidate_range_start()/end(), if
* called between those functions.
*/
- void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm,
- unsigned long start, unsigned long end);
+ void (*invalidate_range)(struct mmu_notifier *subscription,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end);
/*
* These callbacks are used with the get/put interface to manage the
@@ -206,7 +208,7 @@ struct mmu_notifier_ops {
* and cannot sleep.
*/
struct mmu_notifier *(*alloc_notifier)(struct mm_struct *mm);
- void (*free_notifier)(struct mmu_notifier *mn);
+ void (*free_notifier)(struct mmu_notifier *subscription);
};
/*
@@ -280,14 +282,14 @@ mmu_notifier_get(const struct mmu_notifier_ops *ops, struct mm_struct *mm)
up_write(&mm->mmap_sem);
return ret;
}
-void mmu_notifier_put(struct mmu_notifier *mn);
+void mmu_notifier_put(struct mmu_notifier *subscription);
void mmu_notifier_synchronize(void);
-extern int mmu_notifier_register(struct mmu_notifier *mn,
+extern int mmu_notifier_register(struct mmu_notifier *subscription,
struct mm_struct *mm);
-extern int __mmu_notifier_register(struct mmu_notifier *mn,
+extern int __mmu_notifier_register(struct mmu_notifier *subscription,
struct mm_struct *mm);
-extern void mmu_notifier_unregister(struct mmu_notifier *mn,
+extern void mmu_notifier_unregister(struct mmu_notifier *subscription,
struct mm_struct *mm);
unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni);
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index a409abfb9f2652..12b35d8b444a4e 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -294,7 +294,7 @@ static void mn_itree_release(struct mmu_notifier_subscriptions *subscriptions,
static void mn_hlist_release(struct mmu_notifier_subscriptions *subscriptions,
struct mm_struct *mm)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
int id;
/*
@@ -302,27 +302,27 @@ static void mn_hlist_release(struct mmu_notifier_subscriptions *subscriptions,
* ->release returns.
*/
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist)
+ hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist)
/*
* If ->release runs before mmu_notifier_unregister it must be
* handled, as it's the only way for the driver to flush all
* existing sptes and stop the driver from establishing any more
* sptes before all the pages in the mm are freed.
*/
- if (mn->ops->release)
- mn->ops->release(mn, mm);
+ if (subscription->ops->release)
+ subscription->ops->release(subscription, mm);
spin_lock(&subscriptions->lock);
while (unlikely(!hlist_empty(&subscriptions->list))) {
- mn = hlist_entry(subscriptions->list.first, struct mmu_notifier,
- hlist);
+ subscription = hlist_entry(subscriptions->list.first,
+ struct mmu_notifier, hlist);
/*
* We arrived before mmu_notifier_unregister so
* mmu_notifier_unregister will do nothing other than to wait
* for ->release to finish and for mmu_notifier_unregister to
* return.
*/
- hlist_del_init_rcu(&mn->hlist);
+ hlist_del_init_rcu(&subscription->hlist);
}
spin_unlock(&subscriptions->lock);
srcu_read_unlock(&srcu, id);
@@ -360,13 +360,15 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
unsigned long start,
unsigned long end)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
int young = 0, id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
- if (mn->ops->clear_flush_young)
- young |= mn->ops->clear_flush_young(mn, mm, start, end);
+ hlist_for_each_entry_rcu(subscription,
+ &mm->notifier_subscriptions->list, hlist) {
+ if (subscription->ops->clear_flush_young)
+ young |= subscription->ops->clear_flush_young(
+ subscription, mm, start, end);
}
srcu_read_unlock(&srcu, id);
@@ -377,13 +379,15 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
unsigned long start,
unsigned long end)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
int young = 0, id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
- if (mn->ops->clear_young)
- young |= mn->ops->clear_young(mn, mm, start, end);
+ hlist_for_each_entry_rcu(subscription,
+ &mm->notifier_subscriptions->list, hlist) {
+ if (subscription->ops->clear_young)
+ young |= subscription->ops->clear_young(subscription,
+ mm, start, end);
}
srcu_read_unlock(&srcu, id);
@@ -393,13 +397,15 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
int __mmu_notifier_test_young(struct mm_struct *mm,
unsigned long address)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
int young = 0, id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
- if (mn->ops->test_young) {
- young = mn->ops->test_young(mn, mm, address);
+ hlist_for_each_entry_rcu(subscription,
+ &mm->notifier_subscriptions->list, hlist) {
+ if (subscription->ops->test_young) {
+ young = subscription->ops->test_young(subscription, mm,
+ address);
if (young)
break;
}
@@ -412,14 +418,15 @@ int __mmu_notifier_test_young(struct mm_struct *mm,
void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
pte_t pte)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list,
- hlist) {
- if (mn->ops->change_pte)
- mn->ops->change_pte(mn, mm, address, pte);
+ hlist_for_each_entry_rcu(subscription,
+ &mm->notifier_subscriptions->list, hlist) {
+ if (subscription->ops->change_pte)
+ subscription->ops->change_pte(subscription, mm, address,
+ pte);
}
srcu_read_unlock(&srcu, id);
}
@@ -456,24 +463,28 @@ static int mn_hlist_invalidate_range_start(
struct mmu_notifier_subscriptions *subscriptions,
struct mmu_notifier_range *range)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
int ret = 0;
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist) {
- if (mn->ops->invalidate_range_start) {
+ hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist) {
+ const struct mmu_notifier_ops *ops = subscription->ops;
+
+ if (ops->invalidate_range_start) {
int _ret;
if (!mmu_notifier_range_blockable(range))
non_block_start();
- _ret = mn->ops->invalidate_range_start(mn, range);
+ _ret = ops->invalidate_range_start(subscription, range);
if (!mmu_notifier_range_blockable(range))
non_block_end();
if (_ret) {
pr_info("%pS callback failed with %d in %sblockable context.\n",
- mn->ops->invalidate_range_start, _ret,
- !mmu_notifier_range_blockable(range) ? "non-" : "");
+ ops->invalidate_range_start, _ret,
+ !mmu_notifier_range_blockable(range) ?
+ "non-" :
+ "");
WARN_ON(mmu_notifier_range_blockable(range) ||
_ret != -EAGAIN);
ret = _ret;
@@ -505,11 +516,11 @@ static void
mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions,
struct mmu_notifier_range *range, bool only_end)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist) {
+ hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist) {
/*
* Call invalidate_range here too to avoid the need for the
* subsystem of having to register an invalidate_range_end
@@ -523,14 +534,16 @@ mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions,
* is safe to do when we know that a call to invalidate_range()
* already happen under page table lock.
*/
- if (!only_end && mn->ops->invalidate_range)
- mn->ops->invalidate_range(mn, range->mm,
- range->start,
- range->end);
- if (mn->ops->invalidate_range_end) {
+ if (!only_end && subscription->ops->invalidate_range)
+ subscription->ops->invalidate_range(subscription,
+ range->mm,
+ range->start,
+ range->end);
+ if (subscription->ops->invalidate_range_end) {
if (!mmu_notifier_range_blockable(range))
non_block_start();
- mn->ops->invalidate_range_end(mn, range);
+ subscription->ops->invalidate_range_end(subscription,
+ range);
if (!mmu_notifier_range_blockable(range))
non_block_end();
}
@@ -556,13 +569,15 @@ void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range,
void __mmu_notifier_invalidate_range(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
- if (mn->ops->invalidate_range)
- mn->ops->invalidate_range(mn, mm, start, end);
+ hlist_for_each_entry_rcu(subscription,
+ &mm->notifier_subscriptions->list, hlist) {
+ if (subscription->ops->invalidate_range)
+ subscription->ops->invalidate_range(subscription, mm,
+ start, end);
}
srcu_read_unlock(&srcu, id);
}
@@ -572,7 +587,8 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm,
* write mode. A NULL mn signals the notifier is being registered for itree
* mode.
*/
-int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
+int __mmu_notifier_register(struct mmu_notifier *subscription,
+ struct mm_struct *mm)
{
struct mmu_notifier_subscriptions *subscriptions = NULL;
int ret;
@@ -629,14 +645,14 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
if (subscriptions)
smp_store_release(&mm->notifier_subscriptions, subscriptions);
- if (mn) {
+ if (subscription) {
/* Pairs with the mmdrop in mmu_notifier_unregister_* */
mmgrab(mm);
- mn->mm = mm;
- mn->users = 1;
+ subscription->mm = mm;
+ subscription->users = 1;
spin_lock(&mm->notifier_subscriptions->lock);
- hlist_add_head_rcu(&mn->hlist,
+ hlist_add_head_rcu(&subscription->hlist,
&mm->notifier_subscriptions->list);
spin_unlock(&mm->notifier_subscriptions->lock);
} else
@@ -668,15 +684,16 @@ EXPORT_SYMBOL_GPL(__mmu_notifier_register);
* mmu_notifier_unregister() or mmu_notifier_put() must be always called to
* unregister the notifier.
*
- * While the caller has a mmu_notifier get the mn->mm pointer will remain
+ * While the caller has a mmu_notifier get the subscription->mm pointer will remain
* valid, and can be converted to an active mm pointer via mmget_not_zero().
*/
-int mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
+int mmu_notifier_register(struct mmu_notifier *subscription,
+ struct mm_struct *mm)
{
int ret;
down_write(&mm->mmap_sem);
- ret = __mmu_notifier_register(mn, mm);
+ ret = __mmu_notifier_register(subscription, mm);
up_write(&mm->mmap_sem);
return ret;
}
@@ -685,20 +702,20 @@ EXPORT_SYMBOL_GPL(mmu_notifier_register);
static struct mmu_notifier *
find_get_mmu_notifier(struct mm_struct *mm, const struct mmu_notifier_ops *ops)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
spin_lock(&mm->notifier_subscriptions->lock);
- hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list,
- hlist) {
- if (mn->ops != ops)
+ hlist_for_each_entry_rcu(subscription,
+ &mm->notifier_subscriptions->list, hlist) {
+ if (subscription->ops != ops)
continue;
- if (likely(mn->users != UINT_MAX))
- mn->users++;
+ if (likely(subscription->users != UINT_MAX))
+ subscription->users++;
else
- mn = ERR_PTR(-EOVERFLOW);
+ subscription = ERR_PTR(-EOVERFLOW);
spin_unlock(&mm->notifier_subscriptions->lock);
- return mn;
+ return subscription;
}
spin_unlock(&mm->notifier_subscriptions->lock);
return NULL;
@@ -724,27 +741,27 @@ find_get_mmu_notifier(struct mm_struct *mm, const struct mmu_notifier_ops *ops)
struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
struct mm_struct *mm)
{
- struct mmu_notifier *mn;
+ struct mmu_notifier *subscription;
int ret;
lockdep_assert_held_write(&mm->mmap_sem);
if (mm->notifier_subscriptions) {
- mn = find_get_mmu_notifier(mm, ops);
- if (mn)
- return mn;
+ subscription = find_get_mmu_notifier(mm, ops);
+ if (subscription)
+ return subscription;
}
- mn = ops->alloc_notifier(mm);
- if (IS_ERR(mn))
- return mn;
- mn->ops = ops;
- ret = __mmu_notifier_register(mn, mm);
+ subscription = ops->alloc_notifier(mm);
+ if (IS_ERR(subscription))
+ return subscription;
+ subscription->ops = ops;
+ ret = __mmu_notifier_register(subscription, mm);
if (ret)
goto out_free;
- return mn;
+ return subscription;
out_free:
- mn->ops->free_notifier(mn);
+ subscription->ops->free_notifier(subscription);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(mmu_notifier_get_locked);
@@ -767,11 +784,12 @@ void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
* and only after mmu_notifier_unregister returned we're guaranteed
* that ->release or any other method can't run anymore.
*/
-void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm)
+void mmu_notifier_unregister(struct mmu_notifier *subscription,
+ struct mm_struct *mm)
{
BUG_ON(atomic_read(&mm->mm_count) <= 0);
- if (!hlist_unhashed(&mn->hlist)) {
+ if (!hlist_unhashed(&subscription->hlist)) {
/*
* SRCU here will force exit_mmap to wait for ->release to
* finish before freeing the pages.
@@ -783,8 +801,8 @@ void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm)
* exit_mmap will block in mmu_notifier_release to guarantee
* that ->release is called before freeing the pages.
*/
- if (mn->ops->release)
- mn->ops->release(mn, mm);
+ if (subscription->ops->release)
+ subscription->ops->release(subscription, mm);
srcu_read_unlock(&srcu, id);
spin_lock(&mm->notifier_subscriptions->lock);
@@ -792,7 +810,7 @@ void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm)
* Can not use list_del_rcu() since __mmu_notifier_release
* can delete it before we hold the lock.
*/
- hlist_del_init_rcu(&mn->hlist);
+ hlist_del_init_rcu(&subscription->hlist);
spin_unlock(&mm->notifier_subscriptions->lock);
}
@@ -810,10 +828,11 @@ EXPORT_SYMBOL_GPL(mmu_notifier_unregister);
static void mmu_notifier_free_rcu(struct rcu_head *rcu)
{
- struct mmu_notifier *mn = container_of(rcu, struct mmu_notifier, rcu);
- struct mm_struct *mm = mn->mm;
+ struct mmu_notifier *subscription =
+ container_of(rcu, struct mmu_notifier, rcu);
+ struct mm_struct *mm = subscription->mm;
- mn->ops->free_notifier(mn);
+ subscription->ops->free_notifier(subscription);
/* Pairs with the get in __mmu_notifier_register() */
mmdrop(mm);
}
@@ -840,17 +859,17 @@ static void mmu_notifier_free_rcu(struct rcu_head *rcu)
* Modules calling this function must call mmu_notifier_synchronize() in
* their __exit functions to ensure the async work is completed.
*/
-void mmu_notifier_put(struct mmu_notifier *mn)
+void mmu_notifier_put(struct mmu_notifier *subscription)
{
- struct mm_struct *mm = mn->mm;
+ struct mm_struct *mm = subscription->mm;
spin_lock(&mm->notifier_subscriptions->lock);
- if (WARN_ON(!mn->users) || --mn->users)
+ if (WARN_ON(!subscription->users) || --subscription->users)
goto out_unlock;
- hlist_del_init_rcu(&mn->hlist);
+ hlist_del_init_rcu(&subscription->hlist);
spin_unlock(&mm->notifier_subscriptions->lock);
- call_srcu(&srcu, &mn->rcu, mmu_notifier_free_rcu);
+ call_srcu(&srcu, &subscription->rcu, mmu_notifier_free_rcu);
return;
out_unlock:
--
2.24.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/3] mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier
2020-01-16 16:39 [PATCH 0/3] Rename variables in mmu_notifier.c Jason Gunthorpe
2020-01-16 16:39 ` [PATCH 1/3] mm/mmu_notifier: Rename struct mmu_notifier_mm to mmu_notifier_subscriptions Jason Gunthorpe
2020-01-16 16:39 ` [PATCH 2/3] mm/mmu_notifiers: Use 'subscription' as the variable name for mmu_notifier Jason Gunthorpe
@ 2020-01-16 16:39 ` Jason Gunthorpe
2020-01-27 20:52 ` [PATCH 0/3] Rename variables in mmu_notifier.c Jason Gunthorpe
3 siblings, 0 replies; 5+ messages in thread
From: Jason Gunthorpe @ 2020-01-16 16:39 UTC (permalink / raw)
To: linux-mm, Daniel Vetter, Jerome Glisse, Ralph Campbell
Cc: linux-rdma, Jason Gunthorpe
From: Jason Gunthorpe <jgg@mellanox.com>
The 'interval_sub' is placed on the 'notifier_subscriptions' interval
tree.
This eliminates the poor name 'mni' for this variable.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---
Documentation/vm/hmm.rst | 20 +++---
include/linux/mmu_notifier.h | 38 +++++-----
mm/mmu_notifier.c | 136 +++++++++++++++++++----------------
3 files changed, 104 insertions(+), 90 deletions(-)
diff --git a/Documentation/vm/hmm.rst b/Documentation/vm/hmm.rst
index 893a8ba0e9fefb..95fec596836262 100644
--- a/Documentation/vm/hmm.rst
+++ b/Documentation/vm/hmm.rst
@@ -149,14 +149,14 @@ CPU page table into a device page table; HMM helps keep both synchronized. A
device driver that wants to mirror a process address space must start with the
registration of a mmu_interval_notifier::
- mni->ops = &driver_ops;
- int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
- unsigned long start, unsigned long length,
- struct mm_struct *mm);
+ int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub,
+ struct mm_struct *mm, unsigned long start,
+ unsigned long length,
+ const struct mmu_interval_notifier_ops *ops);
-During the driver_ops->invalidate() callback the device driver must perform
-the update action to the range (mark range read only, or fully unmap,
-etc.). The device must complete the update before the driver callback returns.
+During the ops->invalidate() callback the device driver must perform the
+update action to the range (mark range read only, or fully unmap, etc.). The
+device must complete the update before the driver callback returns.
When the device driver wants to populate a range of virtual addresses, it can
use::
@@ -183,7 +183,7 @@ The usage pattern is::
struct hmm_range range;
...
- range.notifier = &mni;
+ range.notifier = &interval_sub;
range.start = ...;
range.end = ...;
range.pfns = ...;
@@ -191,11 +191,11 @@ The usage pattern is::
range.values = ...;
range.pfn_shift = ...;
- if (!mmget_not_zero(mni->notifier.mm))
+ if (!mmget_not_zero(interval_sub->notifier.mm))
return -EFAULT;
again:
- range.notifier_seq = mmu_interval_read_begin(&mni);
+ range.notifier_seq = mmu_interval_read_begin(&interval_sub);
down_read(&mm->mmap_sem);
ret = hmm_range_fault(&range, HMM_RANGE_SNAPSHOT);
if (ret) {
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 4342fa75dc24cd..736f6918335edd 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -237,7 +237,7 @@ struct mmu_notifier {
* was required but mmu_notifier_range_blockable(range) is false.
*/
struct mmu_interval_notifier_ops {
- bool (*invalidate)(struct mmu_interval_notifier *mni,
+ bool (*invalidate)(struct mmu_interval_notifier *interval_sub,
const struct mmu_notifier_range *range,
unsigned long cur_seq);
};
@@ -292,20 +292,21 @@ extern int __mmu_notifier_register(struct mmu_notifier *subscription,
extern void mmu_notifier_unregister(struct mmu_notifier *subscription,
struct mm_struct *mm);
-unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni);
-int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
+unsigned long
+mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub);
+int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub,
struct mm_struct *mm, unsigned long start,
unsigned long length,
const struct mmu_interval_notifier_ops *ops);
int mmu_interval_notifier_insert_locked(
- struct mmu_interval_notifier *mni, struct mm_struct *mm,
+ struct mmu_interval_notifier *interval_sub, struct mm_struct *mm,
unsigned long start, unsigned long length,
const struct mmu_interval_notifier_ops *ops);
-void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni);
+void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub);
/**
* mmu_interval_set_seq - Save the invalidation sequence
- * @mni - The mni passed to invalidate
+ * @interval_sub - The subscription passed to invalidate
* @cur_seq - The cur_seq passed to the invalidate() callback
*
* This must be called unconditionally from the invalidate callback of a
@@ -316,15 +317,16 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni);
* If the caller does not call mmu_interval_read_begin() or
* mmu_interval_read_retry() then this call is not required.
*/
-static inline void mmu_interval_set_seq(struct mmu_interval_notifier *mni,
- unsigned long cur_seq)
+static inline void
+mmu_interval_set_seq(struct mmu_interval_notifier *interval_sub,
+ unsigned long cur_seq)
{
- WRITE_ONCE(mni->invalidate_seq, cur_seq);
+ WRITE_ONCE(interval_sub->invalidate_seq, cur_seq);
}
/**
* mmu_interval_read_retry - End a read side critical section against a VA range
- * mni: The range
+ * interval_sub: The subscription
* seq: The return of the paired mmu_interval_read_begin()
*
* This MUST be called under a user provided lock that is also held
@@ -336,15 +338,16 @@ static inline void mmu_interval_set_seq(struct mmu_interval_notifier *mni,
* Returns true if an invalidation collided with this critical section, and
* the caller should retry.
*/
-static inline bool mmu_interval_read_retry(struct mmu_interval_notifier *mni,
- unsigned long seq)
+static inline bool
+mmu_interval_read_retry(struct mmu_interval_notifier *interval_sub,
+ unsigned long seq)
{
- return mni->invalidate_seq != seq;
+ return interval_sub->invalidate_seq != seq;
}
/**
* mmu_interval_check_retry - Test if a collision has occurred
- * mni: The range
+ * interval_sub: The subscription
* seq: The return of the matching mmu_interval_read_begin()
*
* This can be used in the critical section between mmu_interval_read_begin()
@@ -359,11 +362,12 @@ static inline bool mmu_interval_read_retry(struct mmu_interval_notifier *mni,
* This call can be used as part of loops and other expensive operations to
* expedite a retry.
*/
-static inline bool mmu_interval_check_retry(struct mmu_interval_notifier *mni,
- unsigned long seq)
+static inline bool
+mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub,
+ unsigned long seq)
{
/* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
- return READ_ONCE(mni->invalidate_seq) != seq;
+ return READ_ONCE(interval_sub->invalidate_seq) != seq;
}
extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm);
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 12b35d8b444a4e..ef3973a5d34a94 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -81,7 +81,7 @@ struct mmu_notifier_subscriptions {
* seq & 1 # True if a writer exists
*
* The later state avoids some expensive work on inv_end in the common case of
- * no mni monitoring the VA.
+ * no mmu_interval_notifier monitoring the VA.
*/
static bool
mn_itree_is_invalidating(struct mmu_notifier_subscriptions *subscriptions)
@@ -114,13 +114,13 @@ mn_itree_inv_start_range(struct mmu_notifier_subscriptions *subscriptions,
}
static struct mmu_interval_notifier *
-mn_itree_inv_next(struct mmu_interval_notifier *mni,
+mn_itree_inv_next(struct mmu_interval_notifier *interval_sub,
const struct mmu_notifier_range *range)
{
struct interval_tree_node *node;
- node = interval_tree_iter_next(&mni->interval_tree, range->start,
- range->end - 1);
+ node = interval_tree_iter_next(&interval_sub->interval_tree,
+ range->start, range->end - 1);
if (!node)
return NULL;
return container_of(node, struct mmu_interval_notifier, interval_tree);
@@ -128,7 +128,7 @@ mn_itree_inv_next(struct mmu_interval_notifier *mni,
static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
{
- struct mmu_interval_notifier *mni;
+ struct mmu_interval_notifier *interval_sub;
struct hlist_node *next;
spin_lock(&subscriptions->lock);
@@ -147,15 +147,16 @@ static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
* they are progressed. This arrangement for tree updates is used to
* avoid using a blocking lock during invalidate_range_start.
*/
- hlist_for_each_entry_safe(mni, next, &subscriptions->deferred_list,
+ hlist_for_each_entry_safe(interval_sub, next,
+ &subscriptions->deferred_list,
deferred_item) {
- if (RB_EMPTY_NODE(&mni->interval_tree.rb))
- interval_tree_insert(&mni->interval_tree,
+ if (RB_EMPTY_NODE(&interval_sub->interval_tree.rb))
+ interval_tree_insert(&interval_sub->interval_tree,
&subscriptions->itree);
else
- interval_tree_remove(&mni->interval_tree,
+ interval_tree_remove(&interval_sub->interval_tree,
&subscriptions->itree);
- hlist_del(&mni->deferred_item);
+ hlist_del(&interval_sub->deferred_item);
}
spin_unlock(&subscriptions->lock);
@@ -165,12 +166,12 @@ static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
/**
* mmu_interval_read_begin - Begin a read side critical section against a VA
* range
- * mni: The range to use
+ * interval_sub: The interval subscription
*
* mmu_iterval_read_begin()/mmu_iterval_read_retry() implement a
- * collision-retry scheme similar to seqcount for the VA range under mni. If
- * the mm invokes invalidation during the critical section then
- * mmu_interval_read_retry() will return true.
+ * collision-retry scheme similar to seqcount for the VA range under
+ * subscription. If the mm invokes invalidation during the critical section
+ * then mmu_interval_read_retry() will return true.
*
* This is useful to obtain shadow PTEs where teardown or setup of the SPTEs
* require a blocking context. The critical region formed by this can sleep,
@@ -181,25 +182,26 @@ static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
*
* The return value should be passed to mmu_interval_read_retry().
*/
-unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
+unsigned long
+mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub)
{
struct mmu_notifier_subscriptions *subscriptions =
- mni->mm->notifier_subscriptions;
+ interval_sub->mm->notifier_subscriptions;
unsigned long seq;
bool is_invalidating;
/*
- * If the mni has a different seq value under the user_lock than we
- * started with then it has collided.
+ * If the subscription has a different seq value under the user_lock
+ * than we started with then it has collided.
*
- * If the mni currently has the same seq value as the subscriptions
- * seq, then it is currently between invalidate_start/end and is
- * colliding.
+ * If the subscription currently has the same seq value as the
+ * subscriptions seq, then it is currently between
+ * invalidate_start/end and is colliding.
*
* The locking looks broadly like this:
* mn_tree_invalidate_start(): mmu_interval_read_begin():
* spin_lock
- * seq = READ_ONCE(mni->invalidate_seq);
+ * seq = READ_ONCE(interval_sub->invalidate_seq);
* seq == subs->invalidate_seq
* spin_unlock
* spin_lock
@@ -208,7 +210,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
* op->invalidate_range():
* user_lock
* mmu_interval_set_seq()
- * mni->invalidate_seq = seq
+ * interval_sub->invalidate_seq = seq
* user_unlock
*
* [Required: mmu_interval_read_retry() == true]
@@ -220,7 +222,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
*
* user_lock
* mmu_interval_read_retry():
- * mni->invalidate_seq != seq
+ * interval_sub->invalidate_seq != seq
* user_unlock
*
* Barriers are not needed here as any races here are closed by an
@@ -229,12 +231,12 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
*/
spin_lock(&subscriptions->lock);
/* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
- seq = READ_ONCE(mni->invalidate_seq);
+ seq = READ_ONCE(interval_sub->invalidate_seq);
is_invalidating = seq == subscriptions->invalidate_seq;
spin_unlock(&subscriptions->lock);
/*
- * mni->invalidate_seq must always be set to an odd value via
+ * interval_sub->invalidate_seq must always be set to an odd value via
* mmu_interval_set_seq() using the provided cur_seq from
* mn_itree_inv_start_range(). This ensures that if seq does wrap we
* will always clear the below sleep in some reasonable time as
@@ -266,13 +268,16 @@ static void mn_itree_release(struct mmu_notifier_subscriptions *subscriptions,
.start = 0,
.end = ULONG_MAX,
};
- struct mmu_interval_notifier *mni;
+ struct mmu_interval_notifier *interval_sub;
unsigned long cur_seq;
bool ret;
- for (mni = mn_itree_inv_start_range(subscriptions, &range, &cur_seq);
- mni; mni = mn_itree_inv_next(mni, &range)) {
- ret = mni->ops->invalidate(mni, &range, cur_seq);
+ for (interval_sub =
+ mn_itree_inv_start_range(subscriptions, &range, &cur_seq);
+ interval_sub;
+ interval_sub = mn_itree_inv_next(interval_sub, &range)) {
+ ret = interval_sub->ops->invalidate(interval_sub, &range,
+ cur_seq);
WARN_ON(!ret);
}
@@ -434,14 +439,17 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
static int mn_itree_invalidate(struct mmu_notifier_subscriptions *subscriptions,
const struct mmu_notifier_range *range)
{
- struct mmu_interval_notifier *mni;
+ struct mmu_interval_notifier *interval_sub;
unsigned long cur_seq;
- for (mni = mn_itree_inv_start_range(subscriptions, range, &cur_seq);
- mni; mni = mn_itree_inv_next(mni, range)) {
+ for (interval_sub =
+ mn_itree_inv_start_range(subscriptions, range, &cur_seq);
+ interval_sub;
+ interval_sub = mn_itree_inv_next(interval_sub, range)) {
bool ret;
- ret = mni->ops->invalidate(mni, range, cur_seq);
+ ret = interval_sub->ops->invalidate(interval_sub, range,
+ cur_seq);
if (!ret) {
if (WARN_ON(mmu_notifier_range_blockable(range)))
continue;
@@ -878,20 +886,21 @@ void mmu_notifier_put(struct mmu_notifier *subscription)
EXPORT_SYMBOL_GPL(mmu_notifier_put);
static int __mmu_interval_notifier_insert(
- struct mmu_interval_notifier *mni, struct mm_struct *mm,
+ struct mmu_interval_notifier *interval_sub, struct mm_struct *mm,
struct mmu_notifier_subscriptions *subscriptions, unsigned long start,
unsigned long length, const struct mmu_interval_notifier_ops *ops)
{
- mni->mm = mm;
- mni->ops = ops;
- RB_CLEAR_NODE(&mni->interval_tree.rb);
- mni->interval_tree.start = start;
+ interval_sub->mm = mm;
+ interval_sub->ops = ops;
+ RB_CLEAR_NODE(&interval_sub->interval_tree.rb);
+ interval_sub->interval_tree.start = start;
/*
* Note that the representation of the intervals in the interval tree
* considers the ending point as contained in the interval.
*/
if (length == 0 ||
- check_add_overflow(start, length - 1, &mni->interval_tree.last))
+ check_add_overflow(start, length - 1,
+ &interval_sub->interval_tree.last))
return -EOVERFLOW;
/* Must call with a mmget() held */
@@ -911,30 +920,31 @@ static int __mmu_interval_notifier_insert(
* possibility for live lock, instead defer the add to
* mn_itree_inv_end() so this algorithm is deterministic.
*
- * In all cases the value for the mni->invalidate_seq should be
+ * In all cases the value for the interval_sub->invalidate_seq should be
* odd, see mmu_interval_read_begin()
*/
spin_lock(&subscriptions->lock);
if (subscriptions->active_invalidate_ranges) {
if (mn_itree_is_invalidating(subscriptions))
- hlist_add_head(&mni->deferred_item,
+ hlist_add_head(&interval_sub->deferred_item,
&subscriptions->deferred_list);
else {
subscriptions->invalidate_seq |= 1;
- interval_tree_insert(&mni->interval_tree,
+ interval_tree_insert(&interval_sub->interval_tree,
&subscriptions->itree);
}
- mni->invalidate_seq = subscriptions->invalidate_seq;
+ interval_sub->invalidate_seq = subscriptions->invalidate_seq;
} else {
WARN_ON(mn_itree_is_invalidating(subscriptions));
/*
- * The starting seq for a mni not under invalidation should be
- * odd, not equal to the current invalidate_seq and
+ * The starting seq for a subscription not under invalidation
+ * should be odd, not equal to the current invalidate_seq and
* invalidate_seq should not 'wrap' to the new seq any time
* soon.
*/
- mni->invalidate_seq = subscriptions->invalidate_seq - 1;
- interval_tree_insert(&mni->interval_tree,
+ interval_sub->invalidate_seq =
+ subscriptions->invalidate_seq - 1;
+ interval_tree_insert(&interval_sub->interval_tree,
&subscriptions->itree);
}
spin_unlock(&subscriptions->lock);
@@ -943,7 +953,7 @@ static int __mmu_interval_notifier_insert(
/**
* mmu_interval_notifier_insert - Insert an interval notifier
- * @mni: Interval notifier to register
+ * @interval_sub: Interval subscription to register
* @start: Starting virtual address to monitor
* @length: Length of the range to monitor
* @mm : mm_struct to attach to
@@ -956,7 +966,7 @@ static int __mmu_interval_notifier_insert(
* The caller must use the normal interval notifier read flow via
* mmu_interval_read_begin() to establish SPTEs for this range.
*/
-int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
+int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub,
struct mm_struct *mm, unsigned long start,
unsigned long length,
const struct mmu_interval_notifier_ops *ops)
@@ -973,13 +983,13 @@ int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
return ret;
subscriptions = mm->notifier_subscriptions;
}
- return __mmu_interval_notifier_insert(mni, mm, subscriptions, start,
- length, ops);
+ return __mmu_interval_notifier_insert(interval_sub, mm, subscriptions,
+ start, length, ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert);
int mmu_interval_notifier_insert_locked(
- struct mmu_interval_notifier *mni, struct mm_struct *mm,
+ struct mmu_interval_notifier *interval_sub, struct mm_struct *mm,
unsigned long start, unsigned long length,
const struct mmu_interval_notifier_ops *ops)
{
@@ -995,14 +1005,14 @@ int mmu_interval_notifier_insert_locked(
return ret;
subscriptions = mm->notifier_subscriptions;
}
- return __mmu_interval_notifier_insert(mni, mm, subscriptions, start,
- length, ops);
+ return __mmu_interval_notifier_insert(interval_sub, mm, subscriptions,
+ start, length, ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked);
/**
* mmu_interval_notifier_remove - Remove a interval notifier
- * @mni: Interval notifier to unregister
+ * @interval_sub: Interval subscription to unregister
*
* This function must be paired with mmu_interval_notifier_insert(). It cannot
* be called from any ops callback.
@@ -1010,9 +1020,9 @@ EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked);
* Once this returns ops callbacks are no longer running on other CPUs and
* will not be called in future.
*/
-void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
+void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub)
{
- struct mm_struct *mm = mni->mm;
+ struct mm_struct *mm = interval_sub->mm;
struct mmu_notifier_subscriptions *subscriptions =
mm->notifier_subscriptions;
unsigned long seq = 0;
@@ -1025,16 +1035,16 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
* remove is being called after insert put this on the
* deferred list, but before the deferred list was processed.
*/
- if (RB_EMPTY_NODE(&mni->interval_tree.rb)) {
- hlist_del(&mni->deferred_item);
+ if (RB_EMPTY_NODE(&interval_sub->interval_tree.rb)) {
+ hlist_del(&interval_sub->deferred_item);
} else {
- hlist_add_head(&mni->deferred_item,
+ hlist_add_head(&interval_sub->deferred_item,
&subscriptions->deferred_list);
seq = subscriptions->invalidate_seq;
}
} else {
- WARN_ON(RB_EMPTY_NODE(&mni->interval_tree.rb));
- interval_tree_remove(&mni->interval_tree,
+ WARN_ON(RB_EMPTY_NODE(&interval_sub->interval_tree.rb));
+ interval_tree_remove(&interval_sub->interval_tree,
&subscriptions->itree);
}
spin_unlock(&subscriptions->lock);
--
2.24.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 0/3] Rename variables in mmu_notifier.c
2020-01-16 16:39 [PATCH 0/3] Rename variables in mmu_notifier.c Jason Gunthorpe
` (2 preceding siblings ...)
2020-01-16 16:39 ` [PATCH 3/3] mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier Jason Gunthorpe
@ 2020-01-27 20:52 ` Jason Gunthorpe
3 siblings, 0 replies; 5+ messages in thread
From: Jason Gunthorpe @ 2020-01-27 20:52 UTC (permalink / raw)
To: linux-mm, Daniel Vetter, Jerome Glisse, Ralph Campbell; +Cc: linux-rdma
On Thu, Jan 16, 2020 at 12:39:42PM -0400, Jason Gunthorpe wrote:
> From: Jason Gunthorpe <jgg@mellanox.com>
>
> Linus has observed that the variable names here do not make a lot of sense,
> revise them as discussed so the file has better readability.
>
> The new names are:
>
> struct mmu_notifier_mm -> struct mmu_notifier_subscriptions
> mmu_notifier_mm or mmn_mm -> subscriptions
> The per mm_struct memory that holds all the notifier subscription list
> heads and interval tree
>
> mn -> subscription (of type struct mmu_notifier)
> A list based subscription to notifications
>
> mni -> interval_sub (of type struct mmu_interval_notifier)
> A VA interval based subscription to notifications
>
> I had originaly thought to also change the struct names, and while they are
> not ideal, it seems that the resulting tree wide churn is probably not
> worthwhile considering the size.
>
> This is intended to have no functional change.
>
> Jason Gunthorpe (3):
> mm/mmu_notifier: Rename struct mmu_notifier_mm to
> mmu_notifier_subscriptions
> mm/mmu_notifiers: Use 'subscription' as the variable name for
> mmu_notifier
> mm/mmu_notifiers: Use 'interval_sub' as the variable for
> mmu_interval_notifier
As there has been no comments, and Linus was favorable to the first
patch, I will go ahead with this during the merge window on the hmm.git
Thanks
Jason
^ permalink raw reply [flat|nested] 5+ messages in thread