Messages in this thread | | | From | David Brownell <> | Subject | Re: [PATCH] Moving spinlock to struct usb_hcd | Date | Sat, 26 Jan 2008 00:21:50 -0800 |
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On Friday 25 January 2008, Romit Dasgupta wrote: > This should help > reduce contention to usb during high load where i/o is happening to > multiple hcds.
Looking at how this lock is used, contention doesn't look likely to be an issue. It's never held for long ...
> @@ -1106,9 +1103,9 @@ EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb); > void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb) > { > /* clear all state linking urb to this dev (and hcd) */ > - spin_lock(&hcd_urb_list_lock); > + spin_lock(&hcd->hcd_urb_list_lock); > list_del_init(&urb->urb_list); > - spin_unlock(&hcd_urb_list_lock); > + spin_unlock(&hcd->hcd_urb_list_lock); > } > EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep); >
Do you have any proof that contention is an actual problem? Because otherwise I see no benefit to such a change.
- Dave
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