Hi All,
I am new to qemu development.
Sorry If this is not the correct forum for this question, it would be great if you could direct me to correct forum.
I am seeing very low virtio network throughput on an older (2.6.18) linux guest vs another newer guest (3.10) both running on the same host. (same config 2 vcpus, no multi Q etc.) I see very high CPU usage on the 2.6.18 guest at very low network throughput and want to profile to find bottleneck.
0.25% :5235 [uhci_hcd] [g] 0xffffffff80182236
0.24% :5235 [uhci_hcd] [g] 0xffffffff8018226a
0.23% :5235 [virtio_ring] [g] vring_new_virtqueue
0.20% :5236 [uhci_hcd] [g] 0xffffffff80182236
0.18% :5236 [uhci_hcd] [g] 0xffffffff8018226a
0.18% :5235 [uhci_hcd] [g] 0xffffffff8016f385
0.14% :5236 [uhci_hcd] [g] 0xffffffff802fbe0f
0.14% :5235 [uhci_hcd] [g] 0xffffffff8001161a
0.14% :5235 [virtio_ring] [g] virtqueue_is_broken
My basic question is - Is there a way I can profile the older version of linux guest so i can see the bottleneck (where the guest is spending CPU cycles) My aim is to see if i can patch the older version in the critical path with improvements made in newer version
Thanks
Kal