path: root/arch/sparc/mm
diff options
authorAndreas Larsson <>2014-12-18 13:23:23 +0100
committerDavid S. Miller <>2014-12-18 12:47:54 -0500
commit66d0f7ec9f1038452178b1993fc07fd96d30fd38 (patch)
tree8894bb4925a29d29301a851d4bb384b68bd6a24d /arch/sparc/mm
parent44e8967d591686463e84a88b46b03beba3ab49fb (diff)
sparc32: destroy_context() and switch_mm() needs to disable interrupts.
Load balancing can be triggered in the critical sections protected by srmmu_context_spinlock in destroy_context() and switch_mm() and can hang the cpu waiting for the rq lock of another cpu that in turn has called switch_mm hangning on srmmu_context_spinlock leading to deadlock. So, disable interrupt while taking srmmu_context_spinlock in destroy_context() and switch_mm() so we don't deadlock. See also commit 77b838fa1ef0 ("[SPARC64]: destroy_context() needs to disable interrupts.") Signed-off-by: Andreas Larsson <> Signed-off-by: David S. Miller <>
Diffstat (limited to 'arch/sparc/mm')
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
index be65f035d18a..5cbc96d801ff 100644
--- a/arch/sparc/mm/srmmu.c
+++ b/arch/sparc/mm/srmmu.c
@@ -460,10 +460,12 @@ static void __init sparc_context_init(int numctx)
void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm,
struct task_struct *tsk)
+ unsigned long flags;
if (mm->context == NO_CONTEXT) {
- spin_lock(&srmmu_context_spinlock);
+ spin_lock_irqsave(&srmmu_context_spinlock, flags);
alloc_context(old_mm, mm);
- spin_unlock(&srmmu_context_spinlock);
+ spin_unlock_irqrestore(&srmmu_context_spinlock, flags);
srmmu_ctxd_set(&srmmu_context_table[mm->context], mm->pgd);
@@ -986,14 +988,15 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
void destroy_context(struct mm_struct *mm)
+ unsigned long flags;
if (mm->context != NO_CONTEXT) {
srmmu_ctxd_set(&srmmu_context_table[mm->context], srmmu_swapper_pg_dir);
- spin_lock(&srmmu_context_spinlock);
+ spin_lock_irqsave(&srmmu_context_spinlock, flags);
- spin_unlock(&srmmu_context_spinlock);
+ spin_unlock_irqrestore(&srmmu_context_spinlock, flags);
mm->context = NO_CONTEXT;