On 2012-07-11 11:53, Avi Kivity wrote: > On 07/03/2012 10:21 PM, Alex Williamson wrote: >> Here's the latest iteration of adding an interface to assert and >> de-assert level interrupts from external drivers like vfio. These >> apply on top of the previous argument cleanup, documentation, and >> sanitization patches for irqfd. It would be great to get this queued >> in next for linux 3.6. >> >> I believe I've addressed all the previous comments, including fixing >> the locking problems in eoifd. I've run this with lockdep adding >> and removing level irqfd/eoifd pairs without any problems. Please >> let me know if there are any further comments. Thanks, > > Is there any performance justification for level irqfd? Don't all > new/high bandwidth devices support msi, and this is just a legacy path? I think we've been there before, but the situation hasn't improved much: Apparently, some GPUs still prefer INTx over MSI. Some wireless chipsets too. And then there is not easily replaceable legacy hardware like old telephony adapters or industrial I/O cards etc. that want this. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
