The patch titled
Subject: kernel/locking/lockdep.c: convert hash tables to hlists
has been added to the -mm tree. Its filename is
kernel-locking-lockdepc-convert-hash-tables-to-hlists.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kernel-locking-lockdepc-convert-hash-tables-to-hlists.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kernel-locking-lockdepc-convert-hash-tables-to-hlists.patch
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------------------------------------------------------
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: kernel/locking/lockdep.c: convert hash tables to hlists
Mike said:
: CONFIG_UBSAN_ALIGNMENT breaks x86-64 kernel with lockdep enabled, i. e
: kernel with CONFIG_UBSAN_ALIGNMENT fails to load without even any error
: message.
:
: The problem is that ubsan callbacks use spinlocks and might be called
: before lockdep is initialized. Particularly this line in the
: reserve_ebda_region function causes problem:
:
: lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
:
: If i put lockdep_init() before reserve_ebda_region call in
: x86_64_start_reservations kernel loads well.
Fix this ordering issue permanently: change lockdep so that it uses hlists
for the hash tables. Unlike a list_head, an hlist_head is in its
initialized state when it is all-zeroes, so lockdep is ready for operation
immediately upon boot - lockdep_init() need not have run.
The patch will also save some memory.
Probably lockdep_init() and lockdep_initialized can be done away with now.
Reported-by: Mike Krinkin <krinkin.m.u@xxxxxxxxx>
Suggested-by: Mike Krinkin <krinkin.m.u@xxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/lockdep.h | 4 +--
kernel/locking/lockdep.c | 42 ++++++++++++++++++-------------------
2 files changed, 23 insertions(+), 23 deletions(-)
diff -puN kernel/locking/lockdep.c~kernel-locking-lockdepc-convert-hash-tables-to-hlists kernel/locking/lockdep.c
--- a/kernel/locking/lockdep.c~kernel-locking-lockdepc-convert-hash-tables-to-hlists
+++ a/kernel/locking/lockdep.c
@@ -292,7 +292,7 @@ LIST_HEAD(all_lock_classes);
#define __classhashfn(key) hash_long((unsigned long)key, CLASSHASH_BITS)
#define classhashentry(key) (classhash_table + __classhashfn((key)))
-static struct list_head classhash_table[CLASSHASH_SIZE];
+static struct hlist_head classhash_table[CLASSHASH_SIZE];
/*
* We put the lock dependency chains into a hash-table as well, to cache
@@ -303,7 +303,7 @@ static struct list_head classhash_table[
#define __chainhashfn(chain) hash_long(chain, CHAINHASH_BITS)
#define chainhashentry(chain) (chainhash_table + __chainhashfn((chain)))
-static struct list_head chainhash_table[CHAINHASH_SIZE];
+static struct hlist_head chainhash_table[CHAINHASH_SIZE];
/*
* The hash key of the lock dependency chains is a hash itself too:
@@ -666,7 +666,7 @@ static inline struct lock_class *
look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
{
struct lockdep_subclass_key *key;
- struct list_head *hash_head;
+ struct hlist_head *hash_head;
struct lock_class *class;
#ifdef CONFIG_DEBUG_LOCKDEP
@@ -719,7 +719,7 @@ look_up_lock_class(struct lockdep_map *l
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return NULL;
- list_for_each_entry_rcu(class, hash_head, hash_entry) {
+ hlist_for_each_entry_rcu(class, hash_head, hash_entry) {
if (class->key == key) {
/*
* Huh! same key, different name? Did someone trample
@@ -742,7 +742,7 @@ static inline struct lock_class *
register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
{
struct lockdep_subclass_key *key;
- struct list_head *hash_head;
+ struct hlist_head *hash_head;
struct lock_class *class;
DEBUG_LOCKS_WARN_ON(!irqs_disabled());
@@ -774,7 +774,7 @@ register_lock_class(struct lockdep_map *
* We have to do the hash-walk again, to avoid races
* with another CPU:
*/
- list_for_each_entry_rcu(class, hash_head, hash_entry) {
+ hlist_for_each_entry_rcu(class, hash_head, hash_entry) {
if (class->key == key)
goto out_unlock_set;
}
@@ -805,7 +805,7 @@ register_lock_class(struct lockdep_map *
* We use RCU's safe list-add method to make
* parallel walking of the hash-list safe:
*/
- list_add_tail_rcu(&class->hash_entry, hash_head);
+ hlist_add_head_rcu(&class->hash_entry, hash_head);
/*
* Add it to the global list of classes:
*/
@@ -2017,7 +2017,7 @@ static inline int lookup_chain_cache(str
u64 chain_key)
{
struct lock_class *class = hlock_class(hlock);
- struct list_head *hash_head = chainhashentry(chain_key);
+ struct hlist_head *hash_head = chainhashentry(chain_key);
struct lock_chain *chain;
struct held_lock *hlock_curr;
int i, j;
@@ -2033,7 +2033,7 @@ static inline int lookup_chain_cache(str
* We can walk it lock-free, because entries only get added
* to the hash:
*/
- list_for_each_entry_rcu(chain, hash_head, entry) {
+ hlist_for_each_entry_rcu(chain, hash_head, entry) {
if (chain->chain_key == chain_key) {
cache_hit:
debug_atomic_inc(chain_lookup_hits);
@@ -2057,7 +2057,7 @@ cache_hit:
/*
* We have to walk the chain again locked - to avoid duplicates:
*/
- list_for_each_entry(chain, hash_head, entry) {
+ hlist_for_each_entry(chain, hash_head, entry) {
if (chain->chain_key == chain_key) {
graph_unlock();
goto cache_hit;
@@ -2091,7 +2091,7 @@ cache_hit:
}
chain_hlocks[chain->base + j] = class - lock_classes;
}
- list_add_tail_rcu(&chain->entry, hash_head);
+ hlist_add_head_rcu(&chain->entry, hash_head);
debug_atomic_inc(chain_lookup_misses);
inc_chains();
@@ -3875,7 +3875,7 @@ void lockdep_reset(void)
nr_process_chains = 0;
debug_locks = 1;
for (i = 0; i < CHAINHASH_SIZE; i++)
- INIT_LIST_HEAD(chainhash_table + i);
+ INIT_HLIST_HEAD(chainhash_table + i);
raw_local_irq_restore(flags);
}
@@ -3894,7 +3894,7 @@ static void zap_class(struct lock_class
/*
* Unhash the class and remove it from the all_lock_classes list:
*/
- list_del_rcu(&class->hash_entry);
+ hlist_del_rcu(&class->hash_entry);
list_del_rcu(&class->lock_entry);
RCU_INIT_POINTER(class->key, NULL);
@@ -3917,7 +3917,7 @@ static inline int within(const void *add
void lockdep_free_key_range(void *start, unsigned long size)
{
struct lock_class *class;
- struct list_head *head;
+ struct hlist_head *head;
unsigned long flags;
int i;
int locked;
@@ -3930,9 +3930,9 @@ void lockdep_free_key_range(void *start,
*/
for (i = 0; i < CLASSHASH_SIZE; i++) {
head = classhash_table + i;
- if (list_empty(head))
+ if (!head)
continue;
- list_for_each_entry_rcu(class, head, hash_entry) {
+ hlist_for_each_entry_rcu(class, head, hash_entry) {
if (within(class->key, start, size))
zap_class(class);
else if (within(class->name, start, size))
@@ -3962,7 +3962,7 @@ void lockdep_free_key_range(void *start,
void lockdep_reset_lock(struct lockdep_map *lock)
{
struct lock_class *class;
- struct list_head *head;
+ struct hlist_head *head;
unsigned long flags;
int i, j;
int locked;
@@ -3987,9 +3987,9 @@ void lockdep_reset_lock(struct lockdep_m
locked = graph_lock();
for (i = 0; i < CLASSHASH_SIZE; i++) {
head = classhash_table + i;
- if (list_empty(head))
+ if (!head)
continue;
- list_for_each_entry_rcu(class, head, hash_entry) {
+ hlist_for_each_entry_rcu(class, head, hash_entry) {
int match = 0;
for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
@@ -4027,10 +4027,10 @@ void lockdep_init(void)
return;
for (i = 0; i < CLASSHASH_SIZE; i++)
- INIT_LIST_HEAD(classhash_table + i);
+ INIT_HLIST_HEAD(classhash_table + i);
for (i = 0; i < CHAINHASH_SIZE; i++)
- INIT_LIST_HEAD(chainhash_table + i);
+ INIT_HLIST_HEAD(chainhash_table + i);
lockdep_initialized = 1;
}
diff -puN include/linux/lockdep.h~kernel-locking-lockdepc-convert-hash-tables-to-hlists include/linux/lockdep.h
--- a/include/linux/lockdep.h~kernel-locking-lockdepc-convert-hash-tables-to-hlists
+++ a/include/linux/lockdep.h
@@ -66,7 +66,7 @@ struct lock_class {
/*
* class-hash:
*/
- struct list_head hash_entry;
+ struct hlist_node hash_entry;
/*
* global list of all lock-classes:
@@ -199,7 +199,7 @@ struct lock_chain {
u8 irq_context;
u8 depth;
u16 base;
- struct list_head entry;
+ struct hlist_node entry;
u64 chain_key;
};
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
i-need-old-gcc.patch
arch-alpha-kernel-systblss-remove-debug-check.patch
drivers-gpu-drm-i915-intel_spritec-fix-build.patch
drivers-gpu-drm-i915-intel_tvc-fix-build.patch
arm-arch-arm-include-asm-pageh-needs-personalityh.patch
ocfs2-code-clean-up-for-direct-io-fix.patch
ocfs2-fix-ip_unaligned_aio-deadlock-with-dio-work-queue-fix.patch
ocfs2-dlm-move-lock-to-the-tail-of-grant-queue-while-doing-in-place-convert-fix.patch
kernel-locking-lockdepc-convert-hash-tables-to-hlists.patch
mm.patch
mm-slab-clean-up-debug_pagealloc-processing-code-fix.patch
mm-slab-put-the-freelist-at-the-end-of-slab-page-fix.patch
fs-mpagec-mpage_readpages-use-lru_to_page-helper.patch
mm-page_allocc-introduce-kernelcore=mirror-option-fix.patch
mm-page_allocc-rework-code-layout-in-memmap_init_zone.patch
mm-debug-pageallocc-split-out-page-poisoning-from-debug-page_alloc-checkpatch-fixes.patch
mm-page_poisonc-enable-page_poisoning-as-a-separate-option-fix.patch
mm-page_poisoningc-allow-for-zero-poisoning-checkpatch-fixes.patch
mm-madvise-update-comment-on-sys_madvise-fix.patch
mm-migrate-do-not-touch-page-mem_cgroup-of-live-pages-fix.patch
mm-simplify-lock_page_memcg-fix.patch
ksm-introduce-ksm_max_page_sharing-per-page-deduplication-limit-fix-2.patch
zram-export-the-number-of-available-comp-streams-fix.patch
mm-oom-rework-oom-detection-checkpatch-fixes.patch
mm-use-watermak-checks-for-__gfp_repeat-high-order-allocations-checkpatch-fixes.patch
sched-add-schedule_timeout_idle.patch
btrfs-use-radix_tree_iter_retry-fix.patch
sparc-compat-provide-an-accurate-in_compat_syscall-implementation-fix.patch
sparc-compat-provide-an-accurate-in_compat_syscall-implementation-fix-fix.patch
dma-rename-dma__writecombine-to-dma__wc-checkpatch-fixes.patch
linux-next-git-rejects.patch
drivers-net-wireless-intel-iwlwifi-dvm-calibc-fix-min-warning.patch
do_shared_fault-check-that-mmap_sem-is-held.patch
kernel-forkc-export-kernel_thread-to-modules.patch
slab-leaks3-default-y.patch
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