Re: e1000 PXE breakage bisected down in kvm-userspace

[Anthony Liguori]

Charles Duffy wrote:
Per subject. "git bisect run" script (and libvirt xml helper) attached.

Does the problem go away if you make the e1000_can_receive() function 
always return 1?

Regards,

Anthony Liguori

87b5acf6125d205119e3194c02ed6e71715517dc is first bad commit
commit 87b5acf6125d205119e3194c02ed6e71715517dc
Author: Anthony Liguori <[EMAIL PROTECTED]>
Date:   Wed May 7 13:09:40 2008 -0500

    kvm: qemu: stop dropping so many RX packets in tap
        Normally, tap always reads packets and simply lets the client 
drop them if it
    cannot receive them.  For virtio-net, this results in massive 
packet loss and
    about an 80% performance loss in TCP throughput.
        This patch modifies qemu_send_packet() to only deliver a 
packet to a VLAN
    client if it doesn't have a fd_can_read method or the fd_can_read 
method
    indicates that it can receive packets.  We also return a status 
of whether
    any clients were able to receive the packet.
        If no clients were able to receive a packet, we buffer the 
packet until a
    client indicates that it can receive packets again.
        This patch also modifies the tap code to only read from the 
tap fd if at least
    one client on the VLAN is able to receive a packet.
        Finally, this patch changes the tap code to drain all 
possible packets from
    the tap device when the tap fd is readable.
        Signed-off-by: Anthony Liguori <[EMAIL PROTECTED]>
    Signed-off-by: Avi Kivity <[EMAIL PROTECTED]>

:040000 040000 648a4d52612e0ce68167f279d30bd3f4ec0f22f4 
85352e7b252abb1247af2f024eab10a3e8ec0084 M    qemu

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html