Thanks for the hint+ Thomas. V2 moves allocation outside the lock.
drivers/dca: convert dca_lock to a raw spinlock
[ 25.607517] igb 0000:01:00.0: DCA enabled
[ 25.607524] BUG: sleeping function called from invalid context at kernel/rtmutex.c:684
[ 25.607528] pcnt: 1 0 in_atomic(): 1, irqs_disabled(): 0, pid: 1805, name: modprobe
[ 25.607532] Pid: 1805, comm: modprobe Tainted: G M W N 2.6.33.5-rt23-rt_debug #2
[ 25.607536] Call Trace:
[ 25.607557] [<ffffffff820078a1>] try_stack_unwind+0x151/0x1a0
[ 25.607566] [<ffffffff820062c2>] dump_trace+0x92/0x370
[ 25.607573] [<ffffffff8200731c>] show_trace_log_lvl+0x5c/0x80
[ 25.607578] [<ffffffff82007355>] show_trace+0x15/0x20
[ 25.607587] [<ffffffff823f4588>] dump_stack+0x77/0x8f
[ 25.607595] [<ffffffff82043f2a>] __might_sleep+0x11a/0x130
[ 25.607602] [<ffffffff823f7b93>] rt_spin_lock+0x83/0x90
[ 25.607611] [<ffffffffa0209138>] dca_common_get_tag+0x28/0x80 [dca]
[ 25.607622] [<ffffffffa02091c8>] dca3_get_tag+0x18/0x20 [dca]
[ 25.607634] [<ffffffffa0244e71>] igb_update_dca+0xb1/0x1d0 [igb]
[ 25.607649] [<ffffffffa0244ff5>] igb_setup_dca+0x65/0x80 [igb]
[ 25.607663] [<ffffffffa02535a6>] igb_probe+0x946/0xe4d [igb]
[ 25.607678] [<ffffffff82247517>] local_pci_probe+0x17/0x20
[ 25.607686] [<ffffffff82248661>] pci_device_probe+0x121/0x130
[ 25.607699] [<ffffffff822e4832>] driver_probe_device+0xd2/0x2e0
[ 25.607707] [<ffffffff822e4adb>] __driver_attach+0x9b/0xa0
[ 25.607714] [<ffffffff822e3d1b>] bus_for_each_dev+0x6b/0xa0
[ 25.607720] [<ffffffff822e4591>] driver_attach+0x21/0x30
[ 25.607727] [<ffffffff822e3425>] bus_add_driver+0x1e5/0x350
[ 25.607734] [<ffffffff822e4e41>] driver_register+0x81/0x160
[ 25.607742] [<ffffffff8224890f>] __pci_register_driver+0x6f/0xf0
[ 25.607752] [<ffffffffa011505b>] igb_init_module+0x5b/0x5d [igb]
[ 25.607769] [<ffffffff820001dd>] do_one_initcall+0x3d/0x1a0
[ 25.607778] [<ffffffff820961f6>] sys_init_module+0xe6/0x270
[ 25.607786] [<ffffffff82003232>] system_call_fastpath+0x16/0x1b
[ 25.607794] [<00007f84d6783f4a>] 0x7f84d6783f4a
Signed-off-by: Mike Galbraith <mgalbraith@xxxxxxx>
LKML-Reference: <new-submission>
---
drivers/dca/dca-core.c | 62 +++++++++++++++++++++++++++----------------------
1 file changed, 35 insertions(+), 27 deletions(-)
Index: linux-2.6/drivers/dca/dca-core.c
===================================================================
--- linux-2.6.orig/drivers/dca/dca-core.c
+++ linux-2.6/drivers/dca/dca-core.c
@@ -35,7 +35,7 @@ MODULE_VERSION(DCA_VERSION);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Intel Corporation");
-static DEFINE_SPINLOCK(dca_lock);
+static DEFINE_RAW_SPINLOCK(dca_lock);
static LIST_HEAD(dca_domains);
@@ -88,13 +88,6 @@ static struct dca_domain *dca_get_domain
rc = dca_pci_rc_from_dev(dev);
domain = dca_find_domain(rc);
-
- if (!domain) {
- domain = dca_allocate_domain(rc);
- if (domain)
- list_add(&domain->node, &dca_domains);
- }
-
return domain;
}
@@ -140,19 +133,19 @@ int dca_add_requester(struct device *dev
if (!dev)
return -EFAULT;
- spin_lock_irqsave(&dca_lock, flags);
+ raw_spin_lock_irqsave(&dca_lock, flags);
/* check if the requester has not been added already */
dca = dca_find_provider_by_dev(dev);
if (dca) {
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
return -EEXIST;
}
pci_rc = dca_pci_rc_from_dev(dev);
domain = dca_find_domain(pci_rc);
if (!domain) {
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
return -ENODEV;
}
@@ -162,17 +155,17 @@ int dca_add_requester(struct device *dev
break;
}
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
if (slot < 0)
return slot;
err = dca_sysfs_add_req(dca, dev, slot);
if (err) {
- spin_lock_irqsave(&dca_lock, flags);
+ raw_spin_lock_irqsave(&dca_lock, flags);
if (dca == dca_find_provider_by_dev(dev))
dca->ops->remove_requester(dca, dev);
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
return err;
}
@@ -193,14 +186,14 @@ int dca_remove_requester(struct device *
if (!dev)
return -EFAULT;
- spin_lock_irqsave(&dca_lock, flags);
+ raw_spin_lock_irqsave(&dca_lock, flags);
dca = dca_find_provider_by_dev(dev);
if (!dca) {
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
return -ENODEV;
}
slot = dca->ops->remove_requester(dca, dev);
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
if (slot < 0)
return slot;
@@ -222,16 +215,16 @@ u8 dca_common_get_tag(struct device *dev
u8 tag;
unsigned long flags;
- spin_lock_irqsave(&dca_lock, flags);
+ raw_spin_lock_irqsave(&dca_lock, flags);
dca = dca_find_provider_by_dev(dev);
if (!dca) {
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
return -ENODEV;
}
tag = dca->ops->get_tag(dca, dev, cpu);
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
return tag;
}
@@ -304,23 +297,38 @@ int register_dca_provider(struct dca_pro
{
int err;
unsigned long flags;
- struct dca_domain *domain;
+ struct dca_domain *domain, *newdomain = NULL;
+ struct pci_bus *rc;
err = dca_sysfs_add_provider(dca, dev);
if (err)
return err;
- spin_lock_irqsave(&dca_lock, flags);
+ raw_spin_lock_irqsave(&dca_lock, flags);
+ rc = dca_pci_rc_from_dev(dev);
domain = dca_get_domain(dev);
if (!domain) {
- spin_unlock_irqrestore(&dca_lock, flags);
- return -ENODEV;
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
+
+ newdomain = dca_allocate_domain(rc);
+ if (!newdomain)
+ return -ENODEV;
+
+ raw_spin_lock_irqsave(&dca_lock, flags);
+ /* Recheck, we might have raced after dropping the lock */
+ domain = dca_get_domain(dev);
+ if (!domain) {
+ domain = newdomain;
+ newdomain = NULL;
+ list_add(&domain->node, &dca_domains);
+ }
}
list_add(&dca->node, &domain->dca_providers);
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
blocking_notifier_call_chain(&dca_provider_chain,
DCA_PROVIDER_ADD, NULL);
+ kfree(newdomain);
return 0;
}
EXPORT_SYMBOL_GPL(register_dca_provider);
@@ -338,7 +346,7 @@ void unregister_dca_provider(struct dca_
blocking_notifier_call_chain(&dca_provider_chain,
DCA_PROVIDER_REMOVE, NULL);
- spin_lock_irqsave(&dca_lock, flags);
+ raw_spin_lock_irqsave(&dca_lock, flags);
list_del(&dca->node);
@@ -347,7 +355,7 @@ void unregister_dca_provider(struct dca_
if (list_empty(&domain->dca_providers))
dca_free_domain(domain);
- spin_unlock_irqrestore(&dca_lock, flags);
+ raw_spin_unlock_irqrestore(&dca_lock, flags);
dca_sysfs_remove_provider(dca);
}
--
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
