The patch titled hci_usb: replace mb with smp_mb has been added to the -mm tree. Its filename is hci_usb-replace-mb-with-smp_mb.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: hci_usb: replace mb with smp_mb From: Ming Lei <tom.leiming@xxxxxxxxx> smp_mb is enough for ordering memory operations among processors,and mb is more expensive than smp_mb for UP machine, so replace it with smp_mb(). Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx> Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx> Cc: Dave Young <hidave.darkstar@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/bluetooth/hci_usb.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff -puN drivers/bluetooth/hci_usb.h~hci_usb-replace-mb-with-smp_mb drivers/bluetooth/hci_usb.h --- a/drivers/bluetooth/hci_usb.h~hci_usb-replace-mb-with-smp_mb +++ a/drivers/bluetooth/hci_usb.h @@ -70,8 +70,8 @@ static inline void _urb_queue_head(struc { unsigned long flags; spin_lock_irqsave(&q->lock, flags); - /* _urb_unlink needs to know which spinlock to use, thus mb(). */ - _urb->queue = q; mb(); list_add(&_urb->list, &q->head); + /* _urb_unlink needs to know which spinlock to use, thus smp_mb(). */ + _urb->queue = q; smp_mb(); list_add(&_urb->list, &q->head); spin_unlock_irqrestore(&q->lock, flags); } @@ -79,8 +79,8 @@ static inline void _urb_queue_tail(struc { unsigned long flags; spin_lock_irqsave(&q->lock, flags); - /* _urb_unlink needs to know which spinlock to use, thus mb(). */ - _urb->queue = q; mb(); list_add_tail(&_urb->list, &q->head); + /* _urb_unlink needs to know which spinlock to use, thus smp_mb(). */ + _urb->queue = q; smp_mb(); list_add_tail(&_urb->list, &q->head); spin_unlock_irqrestore(&q->lock, flags); } @@ -89,7 +89,7 @@ static inline void _urb_unlink(struct _u struct _urb_queue *q; unsigned long flags; - mb(); + smp_mb(); q = _urb->queue; /* If q is NULL, it will die at easy-to-debug NULL pointer dereference. No need to BUG(). */ _ Patches currently in -mm which might be from tom.leiming@xxxxxxxxx are hci_usb-replace-mb-with-smp_mb.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html