From: Linus Torvalds <torvalds@linux-foundation.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Sedat Dilek <sedat.dilek@gmail.com>,
Waiman Long <waiman.long@hp.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Jeff Layton <jlayton@redhat.com>,
Miklos Szeredi <mszeredi@suse.cz>, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Andi Kleen <andi@firstfloor.org>,
"Chandramouleeswaran, Aswin" <aswin@hp.com>,
"Norton, Scott J" <scott.norton@hp.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Arnaldo Carvalho de Melo <acme@infradead.org>
Subject: Re: [PATCH v7 1/4] spinlock: A new lockref structure for lockless update of refcount
Date: Tue, 3 Sep 2013 14:13:45 -0700 [thread overview]
Message-ID: <CA+55aFxjkzhdZqayiD9_f_tD3T9UJC2whVie-0K_bzdpogCF5Q@mail.gmail.com> (raw)
In-Reply-To: <CA+55aFz2PmfdaaMUNR8aMn-Hcf8FjsydM7fF28WxZDhBZADHxw@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 394 bytes --]
On Tue, Sep 3, 2013 at 2:05 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> TOTALLY UNTESTED PATCH ATTACHED.
Actually, that was the previous (broken) version of that patch - I
hadn't regenerated it after fixing some stupid compile errors, and it
had the DECLARE parts wrong.
This is the one that actually compiles. Whether it *works* is still a
total mystery.
Linus
[-- Attachment #2: patch.diff --]
[-- Type: application/octet-stream, Size: 6419 bytes --]
fs/file_table.c | 2 +-
fs/internal.h | 2 +-
fs/locks.c | 2 +-
include/linux/lglock.h | 29 ++++++++++++-----------------
kernel/lglock.c | 46 ++++++++++++++++++++++++++--------------------
5 files changed, 41 insertions(+), 40 deletions(-)
diff --git a/fs/file_table.c b/fs/file_table.c
index b44e4c559786..e0bee9e05db9 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -36,7 +36,7 @@ struct files_stat_struct files_stat = {
.max_files = NR_FILE
};
-DEFINE_STATIC_LGLOCK(files_lglock);
+static DEFINE_LGLOCK(files_lglock);
/* SLAB cache for file structures */
static struct kmem_cache *filp_cachep __read_mostly;
diff --git a/fs/internal.h b/fs/internal.h
index 7c5f01cf619d..2db5882d77b2 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -59,7 +59,7 @@ extern int sb_prepare_remount_readonly(struct super_block *);
extern void __init mnt_init(void);
-extern struct lglock vfsmount_lock;
+DECLARE_LGLOCK(vfsmount_lock);
extern int __mnt_want_write(struct vfsmount *);
extern int __mnt_want_write_file(struct file *);
diff --git a/fs/locks.c b/fs/locks.c
index b27a3005d78d..4b4704aee6c6 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -162,7 +162,7 @@ int lease_break_time = 45;
* the file_lock_lglock. Note that alterations to the list also require that
* the relevant i_lock is held.
*/
-DEFINE_STATIC_LGLOCK(file_lock_lglock);
+static DEFINE_LGLOCK(file_lock_lglock);
static DEFINE_PER_CPU(struct hlist_head, file_lock_list);
/*
diff --git a/include/linux/lglock.h b/include/linux/lglock.h
index 0d24e932db0b..232de2c46208 100644
--- a/include/linux/lglock.h
+++ b/include/linux/lglock.h
@@ -42,29 +42,24 @@
#endif
struct lglock {
- arch_spinlock_t __percpu *lock;
+ arch_spinlock_t lock;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lock_class_key lock_key;
struct lockdep_map lock_dep_map;
#endif
};
-#define DEFINE_LGLOCK(name) \
- static DEFINE_PER_CPU(arch_spinlock_t, name ## _lock) \
- = __ARCH_SPIN_LOCK_UNLOCKED; \
- struct lglock name = { .lock = &name ## _lock }
+#define DECLARE_LGLOCK(name) \
+ DECLARE_PER_CPU(struct lglock, name)
+#define DEFINE_LGLOCK(name) \
+ DEFINE_PER_CPU(struct lglock, name) = { .lock = __ARCH_SPIN_LOCK_UNLOCKED }
-#define DEFINE_STATIC_LGLOCK(name) \
- static DEFINE_PER_CPU(arch_spinlock_t, name ## _lock) \
- = __ARCH_SPIN_LOCK_UNLOCKED; \
- static struct lglock name = { .lock = &name ## _lock }
-
-void lg_lock_init(struct lglock *lg, char *name);
-void lg_local_lock(struct lglock *lg);
-void lg_local_unlock(struct lglock *lg);
-void lg_local_lock_cpu(struct lglock *lg, int cpu);
-void lg_local_unlock_cpu(struct lglock *lg, int cpu);
-void lg_global_lock(struct lglock *lg);
-void lg_global_unlock(struct lglock *lg);
+void lg_lock_init(struct lglock __percpu *lg, char *name);
+void lg_local_lock(struct lglock __percpu *lg);
+void lg_local_unlock(struct lglock __percpu *lg);
+void lg_local_lock_cpu(struct lglock __percpu *lg, int cpu);
+void lg_local_unlock_cpu(struct lglock __percpu *lg, int cpu);
+void lg_global_lock(struct lglock __percpu *lg);
+void lg_global_unlock(struct lglock __percpu *lg);
#endif
diff --git a/kernel/lglock.c b/kernel/lglock.c
index 6535a667a5a7..a9e327ba89e6 100644
--- a/kernel/lglock.c
+++ b/kernel/lglock.c
@@ -4,84 +4,90 @@
#include <linux/cpu.h>
#include <linux/string.h>
+/* We only fill in the name and lock_dep_map for the first CPU */
+#define lg_lock_dep_map(lg) \
+ per_cpu_ptr(&lg->lock_dep_map,0)
+#define lg_lock_key(lg) \
+ per_cpu_ptr(&lg->lock_key,0)
+
/*
* Note there is no uninit, so lglocks cannot be defined in
* modules (but it's fine to use them from there)
* Could be added though, just undo lg_lock_init
*/
-void lg_lock_init(struct lglock *lg, char *name)
+void lg_lock_init(struct lglock __percpu *lg, char *name)
{
- LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
+ LOCKDEP_INIT_MAP(lg_lock_dep_map(lg), name, lg_lock_key(lg), 0);
}
EXPORT_SYMBOL(lg_lock_init);
-void lg_local_lock(struct lglock *lg)
+void lg_local_lock(struct lglock __percpu *lg)
{
arch_spinlock_t *lock;
preempt_disable();
- rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_);
- lock = this_cpu_ptr(lg->lock);
+ rwlock_acquire_read(lg_lock_dep_map(lg), 0, 0, _RET_IP_);
+ lock = this_cpu_ptr(&lg->lock);
arch_spin_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock);
-void lg_local_unlock(struct lglock *lg)
+void lg_local_unlock(struct lglock __percpu *lg)
{
arch_spinlock_t *lock;
- rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
- lock = this_cpu_ptr(lg->lock);
+ rwlock_release(lg_lock_dep_map(lg), 1, _RET_IP_);
+ lock = this_cpu_ptr(&lg->lock);
arch_spin_unlock(lock);
preempt_enable();
}
EXPORT_SYMBOL(lg_local_unlock);
-void lg_local_lock_cpu(struct lglock *lg, int cpu)
+void lg_local_lock_cpu(struct lglock __percpu *lg, int cpu)
{
arch_spinlock_t *lock;
preempt_disable();
- rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_);
- lock = per_cpu_ptr(lg->lock, cpu);
+ rwlock_acquire_read(lg_lock_dep_map(lg), 0, 0, _RET_IP_);
+ lock = per_cpu_ptr(&lg->lock, cpu);
arch_spin_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock_cpu);
-void lg_local_unlock_cpu(struct lglock *lg, int cpu)
+void lg_local_unlock_cpu(struct lglock __percpu *lg, int cpu)
{
arch_spinlock_t *lock;
- rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
- lock = per_cpu_ptr(lg->lock, cpu);
+ rwlock_release(lg_lock_dep_map(lg), 1, _RET_IP_);
+ lock = per_cpu_ptr(&lg->lock, cpu);
arch_spin_unlock(lock);
preempt_enable();
}
EXPORT_SYMBOL(lg_local_unlock_cpu);
-void lg_global_lock(struct lglock *lg)
+void lg_global_lock(struct lglock __percpu *lg)
{
int i;
preempt_disable();
- rwlock_acquire(&lg->lock_dep_map, 0, 0, _RET_IP_);
+ rwlock_acquire(lg_lock_dep_map(lg), 0, 0, _RET_IP_);
for_each_possible_cpu(i) {
arch_spinlock_t *lock;
- lock = per_cpu_ptr(lg->lock, i);
+ lock = per_cpu_ptr(&lg->lock, i);
arch_spin_lock(lock);
}
}
EXPORT_SYMBOL(lg_global_lock);
-void lg_global_unlock(struct lglock *lg)
+void lg_global_unlock(struct lglock __percpu *lg)
{
int i;
- rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+ rwlock_release(lg_lock_dep_map(lg), 1, _RET_IP_);
for_each_possible_cpu(i) {
arch_spinlock_t *lock;
- lock = per_cpu_ptr(lg->lock, i);
+ lock = per_cpu_ptr(&lg->lock, i);
arch_spin_unlock(lock);
}
preempt_enable();
next prev parent reply other threads:[~2013-09-03 21:13 UTC|newest]
Thread overview: 151+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-06 3:12 [PATCH v7 0/4] Lockless update of reference count protected by spinlock Waiman Long
2013-08-06 3:12 ` [PATCH v7 1/4] spinlock: A new lockref structure for lockless update of refcount Waiman Long
2013-08-29 1:40 ` Linus Torvalds
2013-08-29 4:44 ` Benjamin Herrenschmidt
2013-08-29 7:00 ` Ingo Molnar
2013-08-29 16:43 ` Linus Torvalds
2013-08-29 19:25 ` Linus Torvalds
2013-08-29 23:42 ` Linus Torvalds
2013-08-30 0:26 ` Benjamin Herrenschmidt
2013-08-30 0:49 ` Linus Torvalds
2013-08-30 2:06 ` Michael Neuling
2013-08-30 2:30 ` Benjamin Herrenschmidt
2013-08-30 2:35 ` Linus Torvalds
2013-08-30 2:45 ` Benjamin Herrenschmidt
2013-08-30 2:31 ` Linus Torvalds
2013-08-30 2:43 ` Benjamin Herrenschmidt
2013-08-30 7:16 ` Ingo Molnar
2013-08-30 15:28 ` Linus Torvalds
2013-08-30 3:12 ` Waiman Long
2013-08-30 3:54 ` Linus Torvalds
2013-08-30 7:55 ` Sedat Dilek
2013-08-30 8:10 ` Sedat Dilek
2013-08-30 9:27 ` Sedat Dilek
2013-08-30 9:48 ` Ingo Molnar
2013-08-30 9:56 ` Sedat Dilek
2013-08-30 9:58 ` Sedat Dilek
2013-08-30 10:29 ` Sedat Dilek
2013-08-30 10:36 ` Peter Zijlstra
2013-08-30 10:44 ` Sedat Dilek
2013-08-30 10:46 ` Sedat Dilek
2013-08-30 10:52 ` Peter Zijlstra
2013-08-30 10:57 ` Sedat Dilek
2013-08-30 14:05 ` Sedat Dilek
2013-08-30 11:19 ` Sedat Dilek
2013-08-30 10:38 ` Sedat Dilek
2013-08-30 15:34 ` Linus Torvalds
2013-08-30 15:38 ` Sedat Dilek
2013-08-30 16:12 ` Steven Rostedt
2013-08-30 16:16 ` Sedat Dilek
2013-08-30 18:42 ` Linus Torvalds
2013-08-30 16:32 ` Linus Torvalds
2013-08-30 16:37 ` Sedat Dilek
2013-08-30 16:52 ` Linus Torvalds
2013-08-30 17:11 ` Sedat Dilek
2013-08-30 17:26 ` Linus Torvalds
2013-09-01 10:01 ` Sedat Dilek
2013-09-01 10:33 ` Sedat Dilek
2013-09-01 15:32 ` Linus Torvalds
2013-09-01 15:45 ` Sedat Dilek
2013-09-01 15:55 ` Linus Torvalds
2013-09-02 10:30 ` Sedat Dilek
2013-09-02 16:09 ` David Ahern
2013-09-01 20:59 ` Linus Torvalds
2013-09-01 21:23 ` Al Viro
2013-09-01 22:16 ` Linus Torvalds
2013-09-01 22:35 ` Al Viro
2013-09-01 22:44 ` Al Viro
2013-09-01 22:58 ` Linus Torvalds
2013-09-01 22:48 ` Linus Torvalds
2013-09-01 23:30 ` Al Viro
2013-09-02 0:12 ` Linus Torvalds
2013-09-02 0:50 ` Linus Torvalds
2013-09-02 7:05 ` Ingo Molnar
2013-09-02 16:44 ` Linus Torvalds
2013-09-03 10:15 ` Ingo Molnar
2013-09-03 15:41 ` Linus Torvalds
2013-09-03 18:34 ` Linus Torvalds
2013-09-03 19:19 ` Ingo Molnar
2013-09-03 21:05 ` Linus Torvalds
2013-09-03 21:13 ` Linus Torvalds [this message]
2013-09-03 21:34 ` Linus Torvalds
2013-09-03 21:39 ` Linus Torvalds
2013-09-03 14:08 ` Pavel Machek
2013-09-03 22:37 ` Sedat Dilek
2013-09-03 22:55 ` Dave Jones
2013-09-03 23:05 ` Sedat Dilek
2013-09-03 23:15 ` Dave Jones
2013-09-03 23:20 ` Sedat Dilek
2013-09-03 23:45 ` Sedat Dilek
2013-08-30 18:33 ` Waiman Long
2013-08-30 18:53 ` Linus Torvalds
2013-08-30 19:20 ` Waiman Long
2013-08-30 19:33 ` Linus Torvalds
2013-08-30 20:15 ` Waiman Long
2013-08-30 20:43 ` Linus Torvalds
2013-08-30 20:54 ` Al Viro
2013-08-30 21:03 ` Linus Torvalds
2013-08-30 21:44 ` Al Viro
2013-08-30 22:30 ` Linus Torvalds
2013-08-31 21:23 ` Al Viro
2013-08-31 22:49 ` Linus Torvalds
2013-08-31 23:27 ` Al Viro
2013-09-01 0:13 ` Al Viro
2013-09-01 17:48 ` Al Viro
2013-09-09 8:30 ` Peter Zijlstra
2013-08-30 21:10 ` Waiman Long
2013-08-30 21:22 ` Linus Torvalds
2013-08-30 21:30 ` Al Viro
2013-08-30 21:42 ` Waiman Long
2013-08-30 19:40 ` Al Viro
2013-08-30 19:52 ` Waiman Long
2013-08-30 20:26 ` Al Viro
2013-08-30 20:35 ` Waiman Long
2013-08-30 20:48 ` Al Viro
2013-08-31 2:02 ` Waiman Long
2013-08-31 2:35 ` Al Viro
2013-08-31 2:42 ` Al Viro
2013-09-02 19:25 ` Waiman Long
2013-09-03 6:01 ` Ingo Molnar
2013-09-03 7:24 ` Sedat Dilek
2013-09-03 15:38 ` Linus Torvalds
2013-09-03 15:14 ` Waiman Long
2013-09-03 15:34 ` Linus Torvalds
2013-09-03 19:09 ` Linus Torvalds
2013-09-03 21:01 ` Waiman Long
2013-09-04 14:52 ` Waiman Long
2013-09-04 15:14 ` Linus Torvalds
2013-09-04 19:25 ` Waiman Long
2013-09-04 21:34 ` Linus Torvalds
2013-09-05 2:35 ` Waiman Long
2013-09-05 13:31 ` Ingo Molnar
2013-09-05 17:33 ` Waiman Long
2013-09-05 17:40 ` Ingo Molnar
2013-09-03 22:41 ` Sedat Dilek
2013-09-03 23:11 ` Sedat Dilek
2013-09-08 21:45 ` Linus Torvalds
2013-09-09 0:03 ` Al Viro
2013-09-09 0:25 ` Linus Torvalds
2013-09-09 0:35 ` Al Viro
2013-09-09 0:38 ` Linus Torvalds
2013-09-09 0:57 ` Al Viro
2013-09-09 2:09 ` Ramkumar Ramachandra
2013-09-09 0:30 ` Al Viro
2013-09-09 3:32 ` Linus Torvalds
2013-09-09 4:06 ` Ramkumar Ramachandra
2013-09-09 5:44 ` Al Viro
2013-08-30 17:17 ` Peter Zijlstra
2013-08-30 17:28 ` Linus Torvalds
2013-08-30 17:33 ` Linus Torvalds
2013-08-29 15:20 ` Waiman Long
2013-08-06 3:12 ` [PATCH v7 2/4] spinlock: Enable x86 architecture to do lockless refcount update Waiman Long
2013-08-06 3:12 ` [PATCH v7 3/4] dcache: replace d_lock/d_count by d_lockcnt Waiman Long
2013-08-06 3:12 ` [PATCH v7 4/4] dcache: Enable lockless update of dentry's refcount Waiman Long
2013-08-13 18:03 ` [PATCH v7 0/4] Lockless update of reference count protected by spinlock Waiman Long
2013-08-31 3:06 [PATCH v7 1/4] spinlock: A new lockref structure for lockless update of refcount George Spelvin
2013-08-31 17:16 ` Linus Torvalds
2013-09-01 8:50 ` George Spelvin
2013-09-01 11:10 ` Theodore Ts'o
2013-09-01 15:49 ` Linus Torvalds
2013-09-01 18:11 ` Steven Rostedt
2013-09-01 20:03 ` Linus Torvalds
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