Attachment 234971 Details for Bug 311391 – DEBUG_PI_LIST RT fix

[patch] DEBUG_PI_LIST RT fix

DEBUG_PI_LIST-rt.patch (text/plain), 1.54 KB, created by Arnaldo Carvalho de Melo on 2007-10-23 11:29:45 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Arnaldo Carvalho de Melo

Created: 2007-10-23 11:29:45 UTC

Size: 1.54 KB

patch

obsolete

>[DEBUG_PI_LIST]: Set plist.lock to NULL on PREEMPT_RT
>
>On RT struct plist_head->lock is a raw_spinlock_t, but struct futex_hash_bucket->lock,
>that is set to plist_head->lock is a spinlock, which becomes a mutex on RT.
>Later in plist_check_head spin_is_locked can't figure out what is the right type,
>triggering a WARN_ON_SMP. As we were already special casing PREEMPT_RT on
>plist_check_head..
>
>Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
>
>diff -uNrp linux-2.6.23-rt1.orig/kernel/futex.c linux-2.6.23-rt1/kernel/futex.c
>--- linux-2.6.23-rt1.orig/kernel/futex.c	2007-10-22 12:28:11.000000000 -0200
>+++ linux-2.6.23-rt1/kernel/futex.c	2007-10-22 12:27:07.000000000 -0200
>@@ -947,9 +947,13 @@ static int futex_requeue(u32 __user *uad
> 				plist_del(&this->list, &hb1->chain);
> 				plist_add(&this->list, &hb2->chain);
> 				this->lock_ptr = &hb2->lock;
>-#if defined(CONFIG_DEBUG_PI_LIST) && !defined(CONFIG_PREEMPT_RT)
>+#ifdef CONFIG_DEBUG_PI_LIST
>+#ifdef CONFIG_PREEMPT_RT
>+				this->list.plist.lock = NULL;
>+#else
> 				this->list.plist.lock = &hb2->lock;
> #endif
>+#endif
> 			}
> 			this->key = key2;
> 			get_futex_key_refs(&key2);
>@@ -1008,9 +1012,13 @@ static inline void __queue_me(struct fut
> 	prio = min(current->normal_prio, MAX_RT_PRIO);
> 
> 	plist_node_init(&q->list, prio);
>-#if defined(CONFIG_DEBUG_PI_LIST) && !defined(CONFIG_PREEMPT_RT)
>+#ifdef CONFIG_DEBUG_PI_LIST
>+#ifdef CONFIG_PREEMPT_RT
>+	q->list.plist.lock = NULL;
>+#else
> 	q->list.plist.lock = &hb->lock;
> #endif
>+#endif
> 	plist_add(&q->list, &hb->chain);
> 	q->task = current;
> 	spin_unlock(&hb->lock);

Actions: View | Diff

Attachments on bug 311391: 234971 | 274001