Hi Avi, > There may be a missing wakeup in the networking path. You can try adding > printf()s in RTL8139's receive function, and in kvm_set_irq_level() to see > if there's a problem in interrupt flow. Thanks for your insights. I debugged the RTL8139's receive function rtl8139_do_receive() and the functions rtl8139_update_irq() (responsible for initiating the rtl8139 interrupts) and kvm_set_irq_level(). I came to know that the packets were not delayed as opposed to previous assumption. Also the interrupts were promptly provided by the rtl8139 using rtl8139_update_irq(). Also it seems kvm_set_irq_level() injects the interrupts to the guest properly. But inside the guest(kitten LWK) I see the number of interrupts to be less than what is injected from KVM. This may be due to the interrupts being coalesced in KVM before injection or the guest somehow misses some interrupts. I feel the coalescing of the interrupts may cause the problem in my application. For eg. Two packets needs to be received, hence instead of injecting two interrupts only one coalesced interrupt is injected to the guest. The RTL8139 driver in guest on receiving the coalesced interrupt reads the first packet(which is present in buffer) but when it tries to read the next packet immediately, the packet has not yet arrived to the guest's RTL8139's buffer hence it assumes no more data and returns. The second packet here is not received leading to retransmission. But in this scenario if a second interrupt occured then the driver would have once again checked the buffer to find the data available thereby avoiding retransmission. Please let me know what is the minimum time between interrupts to be considered for coalescing. Is it possible to reduce this time further as it will be useful in my case. Please let me know your comments on this issue. Thanks for your time, karthik -- 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
