mirror of
https://github.com/linuxkit/linuxkit.git
synced 2025-09-25 16:46:23 +00:00
Upgrade -rt patches to v4.14.29-rt25
Signed-off-by: Tiejun Chen <tiejun.china@gmail.com>
This commit is contained in:
Tiejun Chen
218
kernel/patches-4.14.x-rt/0258-peterz-percpu-rwsem-rt.patch
Normal file
218
kernel/patches-4.14.x-rt/0258-peterz-percpu-rwsem-rt.patch
Normal file
@@ -0,0 +1,218 @@
|
||||
Subject: locking/percpu-rwsem: Remove preempt_disable variants
|
||||
From: Peter Zijlstra <peterz@infradead.org>
|
||||
Date: Wed Nov 23 16:29:32 CET 2016
|
||||
|
||||
Effective revert commit:
|
||||
|
||||
87709e28dc7c ("fs/locks: Use percpu_down_read_preempt_disable()")
|
||||
|
||||
This is causing major pain for PREEMPT_RT and is only a very small
|
||||
performance issue for PREEMPT=y.
|
||||
|
||||
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
|
||||
---
|
||||
---
|
||||
fs/locks.c | 32 ++++++++++++++++----------------
|
||||
include/linux/percpu-rwsem.h | 24 ++++--------------------
|
||||
2 files changed, 20 insertions(+), 36 deletions(-)
|
||||
|
||||
--- a/fs/locks.c
|
||||
+++ b/fs/locks.c
|
||||
@@ -945,7 +945,7 @@ static int flock_lock_inode(struct inode
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
- percpu_down_read_preempt_disable(&file_rwsem);
|
||||
+ percpu_down_read(&file_rwsem);
|
||||
spin_lock(&ctx->flc_lock);
|
||||
if (request->fl_flags & FL_ACCESS)
|
||||
goto find_conflict;
|
||||
@@ -986,7 +986,7 @@ static int flock_lock_inode(struct inode
|
||||
|
||||
out:
|
||||
spin_unlock(&ctx->flc_lock);
|
||||
- percpu_up_read_preempt_enable(&file_rwsem);
|
||||
+ percpu_up_read(&file_rwsem);
|
||||
if (new_fl)
|
||||
locks_free_lock(new_fl);
|
||||
locks_dispose_list(&dispose);
|
||||
@@ -1023,7 +1023,7 @@ static int posix_lock_inode(struct inode
|
||||
new_fl2 = locks_alloc_lock();
|
||||
}
|
||||
|
||||
- percpu_down_read_preempt_disable(&file_rwsem);
|
||||
+ percpu_down_read(&file_rwsem);
|
||||
spin_lock(&ctx->flc_lock);
|
||||
/*
|
||||
* New lock request. Walk all POSIX locks and look for conflicts. If
|
||||
@@ -1195,7 +1195,7 @@ static int posix_lock_inode(struct inode
|
||||
}
|
||||
out:
|
||||
spin_unlock(&ctx->flc_lock);
|
||||
- percpu_up_read_preempt_enable(&file_rwsem);
|
||||
+ percpu_up_read(&file_rwsem);
|
||||
/*
|
||||
* Free any unused locks.
|
||||
*/
|
||||
@@ -1470,7 +1470,7 @@ int __break_lease(struct inode *inode, u
|
||||
return error;
|
||||
}
|
||||
|
||||
- percpu_down_read_preempt_disable(&file_rwsem);
|
||||
+ percpu_down_read(&file_rwsem);
|
||||
spin_lock(&ctx->flc_lock);
|
||||
|
||||
time_out_leases(inode, &dispose);
|
||||
@@ -1522,13 +1522,13 @@ int __break_lease(struct inode *inode, u
|
||||
locks_insert_block(fl, new_fl);
|
||||
trace_break_lease_block(inode, new_fl);
|
||||
spin_unlock(&ctx->flc_lock);
|
||||
- percpu_up_read_preempt_enable(&file_rwsem);
|
||||
+ percpu_up_read(&file_rwsem);
|
||||
|
||||
locks_dispose_list(&dispose);
|
||||
error = wait_event_interruptible_timeout(new_fl->fl_wait,
|
||||
!new_fl->fl_next, break_time);
|
||||
|
||||
- percpu_down_read_preempt_disable(&file_rwsem);
|
||||
+ percpu_down_read(&file_rwsem);
|
||||
spin_lock(&ctx->flc_lock);
|
||||
trace_break_lease_unblock(inode, new_fl);
|
||||
locks_delete_block(new_fl);
|
||||
@@ -1545,7 +1545,7 @@ int __break_lease(struct inode *inode, u
|
||||
}
|
||||
out:
|
||||
spin_unlock(&ctx->flc_lock);
|
||||
- percpu_up_read_preempt_enable(&file_rwsem);
|
||||
+ percpu_up_read(&file_rwsem);
|
||||
locks_dispose_list(&dispose);
|
||||
locks_free_lock(new_fl);
|
||||
return error;
|
||||
@@ -1619,7 +1619,7 @@ int fcntl_getlease(struct file *filp)
|
||||
|
||||
ctx = smp_load_acquire(&inode->i_flctx);
|
||||
if (ctx && !list_empty_careful(&ctx->flc_lease)) {
|
||||
- percpu_down_read_preempt_disable(&file_rwsem);
|
||||
+ percpu_down_read(&file_rwsem);
|
||||
spin_lock(&ctx->flc_lock);
|
||||
time_out_leases(inode, &dispose);
|
||||
list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
|
||||
@@ -1629,7 +1629,7 @@ int fcntl_getlease(struct file *filp)
|
||||
break;
|
||||
}
|
||||
spin_unlock(&ctx->flc_lock);
|
||||
- percpu_up_read_preempt_enable(&file_rwsem);
|
||||
+ percpu_up_read(&file_rwsem);
|
||||
|
||||
locks_dispose_list(&dispose);
|
||||
}
|
||||
@@ -1704,7 +1704,7 @@ generic_add_lease(struct file *filp, lon
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
- percpu_down_read_preempt_disable(&file_rwsem);
|
||||
+ percpu_down_read(&file_rwsem);
|
||||
spin_lock(&ctx->flc_lock);
|
||||
time_out_leases(inode, &dispose);
|
||||
error = check_conflicting_open(dentry, arg, lease->fl_flags);
|
||||
@@ -1775,7 +1775,7 @@ generic_add_lease(struct file *filp, lon
|
||||
lease->fl_lmops->lm_setup(lease, priv);
|
||||
out:
|
||||
spin_unlock(&ctx->flc_lock);
|
||||
- percpu_up_read_preempt_enable(&file_rwsem);
|
||||
+ percpu_up_read(&file_rwsem);
|
||||
locks_dispose_list(&dispose);
|
||||
if (is_deleg)
|
||||
inode_unlock(inode);
|
||||
@@ -1798,7 +1798,7 @@ static int generic_delete_lease(struct f
|
||||
return error;
|
||||
}
|
||||
|
||||
- percpu_down_read_preempt_disable(&file_rwsem);
|
||||
+ percpu_down_read(&file_rwsem);
|
||||
spin_lock(&ctx->flc_lock);
|
||||
list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
|
||||
if (fl->fl_file == filp &&
|
||||
@@ -1811,7 +1811,7 @@ static int generic_delete_lease(struct f
|
||||
if (victim)
|
||||
error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose);
|
||||
spin_unlock(&ctx->flc_lock);
|
||||
- percpu_up_read_preempt_enable(&file_rwsem);
|
||||
+ percpu_up_read(&file_rwsem);
|
||||
locks_dispose_list(&dispose);
|
||||
return error;
|
||||
}
|
||||
@@ -2535,13 +2535,13 @@ locks_remove_lease(struct file *filp, st
|
||||
if (list_empty(&ctx->flc_lease))
|
||||
return;
|
||||
|
||||
- percpu_down_read_preempt_disable(&file_rwsem);
|
||||
+ percpu_down_read(&file_rwsem);
|
||||
spin_lock(&ctx->flc_lock);
|
||||
list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
|
||||
if (filp == fl->fl_file)
|
||||
lease_modify(fl, F_UNLCK, &dispose);
|
||||
spin_unlock(&ctx->flc_lock);
|
||||
- percpu_up_read_preempt_enable(&file_rwsem);
|
||||
+ percpu_up_read(&file_rwsem);
|
||||
|
||||
locks_dispose_list(&dispose);
|
||||
}
|
||||
--- a/include/linux/percpu-rwsem.h
|
||||
+++ b/include/linux/percpu-rwsem.h
|
||||
@@ -29,7 +29,7 @@ static struct percpu_rw_semaphore name =
|
||||
extern int __percpu_down_read(struct percpu_rw_semaphore *, int);
|
||||
extern void __percpu_up_read(struct percpu_rw_semaphore *);
|
||||
|
||||
-static inline void percpu_down_read_preempt_disable(struct percpu_rw_semaphore *sem)
|
||||
+static inline void percpu_down_read(struct percpu_rw_semaphore *sem)
|
||||
{
|
||||
might_sleep();
|
||||
|
||||
@@ -47,16 +47,10 @@ static inline void percpu_down_read_pree
|
||||
__this_cpu_inc(*sem->read_count);
|
||||
if (unlikely(!rcu_sync_is_idle(&sem->rss)))
|
||||
__percpu_down_read(sem, false); /* Unconditional memory barrier */
|
||||
- barrier();
|
||||
/*
|
||||
- * The barrier() prevents the compiler from
|
||||
+ * The preempt_enable() prevents the compiler from
|
||||
* bleeding the critical section out.
|
||||
*/
|
||||
-}
|
||||
-
|
||||
-static inline void percpu_down_read(struct percpu_rw_semaphore *sem)
|
||||
-{
|
||||
- percpu_down_read_preempt_disable(sem);
|
||||
preempt_enable();
|
||||
}
|
||||
|
||||
@@ -83,13 +77,9 @@ static inline int percpu_down_read_trylo
|
||||
return ret;
|
||||
}
|
||||
|
||||
-static inline void percpu_up_read_preempt_enable(struct percpu_rw_semaphore *sem)
|
||||
+static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
|
||||
{
|
||||
- /*
|
||||
- * The barrier() prevents the compiler from
|
||||
- * bleeding the critical section out.
|
||||
- */
|
||||
- barrier();
|
||||
+ preempt_disable();
|
||||
/*
|
||||
* Same as in percpu_down_read().
|
||||
*/
|
||||
@@ -102,12 +92,6 @@ static inline void percpu_up_read_preemp
|
||||
rwsem_release(&sem->rw_sem.dep_map, 1, _RET_IP_);
|
||||
}
|
||||
|
||||
-static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
|
||||
-{
|
||||
- preempt_disable();
|
||||
- percpu_up_read_preempt_enable(sem);
|
||||
-}
|
||||
-
|
||||
extern void percpu_down_write(struct percpu_rw_semaphore *);
|
||||
extern void percpu_up_write(struct percpu_rw_semaphore *);
|
||||
|
||||
Reference in New Issue
Block a user