60 lines
1.6 KiB
Diff
60 lines
1.6 KiB
Diff
From 054879629df5abfef1ecfa85b12b14857d3ee6b3 Mon Sep 17 00:00:00 2001
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From: Steven Rostedt <rostedt@goodmis.org>
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Date: Tue, 29 Apr 2014 20:13:08 -0400
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Subject: [PATCH] rwlock: disable migration before taking a lock
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/3.14/patches-3.14.10-rt7.tar.xz
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If there's no complaints about it. I'm going to add this to the 3.12-rt
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stable tree. As without it, it fails horribly with the cpu hotplug
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stress test, and I wont release a stable kernel that does that.
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Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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---
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kernel/locking/rt.c | 17 ++++++++++-------
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1 file changed, 10 insertions(+), 7 deletions(-)
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--- a/kernel/locking/rt.c
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+++ b/kernel/locking/rt.c
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@@ -180,12 +180,14 @@ EXPORT_SYMBOL(_mutex_unlock);
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*/
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int __lockfunc rt_write_trylock(rwlock_t *rwlock)
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{
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- int ret = rt_mutex_trylock(&rwlock->lock);
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+ int ret;
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- if (ret) {
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+ migrate_disable();
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+ ret = rt_mutex_trylock(&rwlock->lock);
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+ if (ret)
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rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
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- migrate_disable();
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- }
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+ else
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+ migrate_enable();
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return ret;
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}
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@@ -212,9 +214,10 @@ int __lockfunc rt_read_trylock(rwlock_t
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* write locked.
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*/
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if (rt_mutex_owner(lock) != current) {
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+ migrate_disable();
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ret = rt_mutex_trylock(lock);
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- if (ret)
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- migrate_disable();
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+ if (!ret)
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+ migrate_enable();
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} else if (!rwlock->read_depth) {
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ret = 0;
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@@ -247,8 +250,8 @@ void __lockfunc rt_read_lock(rwlock_t *r
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* recursive read locks succeed when current owns the lock
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*/
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if (rt_mutex_owner(lock) != current) {
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- __rt_spin_lock(lock);
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migrate_disable();
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+ __rt_spin_lock(lock);
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}
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rwlock->read_depth++;
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}
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