On Wed, 2005-12-07 at 11:01 -0500, Alan Stern wrote: > On Wed, 7 Dec 2005, Arjan van de Ven wrote: > > > > On the other hand, Oliver needs to be careful about claiming too much. > > > In > > > general atomic_t operations _are_ superior to the spinlock approach. > > > > No they're not. Both are just about equally expensive cpu wise, > > sometimes the atomic_t ones are a bit more expensive (like on parisc > > architecture). But on x86 in either case it's a locked cycle, which is > > just expensive no matter which side you flip the coin... > > You're overgeneralizing.
to some degree yes. > > Sure, a locked cycle has a certain expense. But it's a lot less than the > expense of a contested spinlock. the chances that *this* spinlock ends up being contested are near zero, and.. in that scenario a locked cycle does the same thing, just in hardware..... (eg the other cpu will busy wait until this locked cycle is done) ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
