sparc64: Avoid irqsave/restore on vio.lock if in_softirq()

RFC PATCH Superseded Sowmini Varadhan 1 participant 1 message Oct 15, 2014

Subsystems (3)

Networking Network drivers SPARC + UltraSPARC (sparc/sparc64)

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Sowmini Varadhan

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2014-10-15 16:43 UTC #0 lore raw

RFC PATCH v3 3/4 sparc64: Avoid irqsave/restore on vio.lock if in_softirq()

For NAPIfied drivers , there is no need to synchronize by doing irqsave/restore on vio.lock in the I/O path.

Signed-off-by Sowmini Varadhan <[email protected]>

---
 arch/sparc/kernel/viohs.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

arch/sparc/kernel/viohs.c +5 -3

index 7ef081a..d731586 100644
@@ -747,10 +747,11 @@ EXPORT_SYMBOL(vio_ldc_free);
 
 void vio_port_up(struct vio_driver_state *vio)
 {
-	unsigned long flags;
+	unsigned long flags = 0;
 	int err, state;
 
-	spin_lock_irqsave(&vio->lock, flags);
+	if (!in_softirq())
+		spin_lock_irqsave(&vio->lock, flags);
 
 	state = ldc_state(vio->lp);

@@ -777,7 +778,8 @@ void vio_port_up(struct vio_driver_state *vio)
 		mod_timer(&vio->timer, expires);
 	}
 
-	spin_unlock_irqrestore(&vio->lock, flags);
+	if (!in_softirq())
+		spin_unlock_irqrestore(&vio->lock, flags);
 }
 EXPORT_SYMBOL(vio_port_up);

Signature · 1 line

1.8.4.2