[dpdk-dev] Would you check if there is deadlock in rte_distributor_process() librte_distributor?

최익성 pnk003 at naver.com
Fri Oct 16 08:33:41 CEST 2015

Dear DPDK experts.
Thank you very much for your excellent work and great contributions.
I have a question about distributor library source code.   /dpdk/lib/librte_distributor/rte_distributor.c
In rte_distributor_process(),
rte_distributor_process() { mbufs[] -> d->backlog -> d->bufs }   => lcore_worker() reads d->bufs (with 0x0 empty flag packet) and sets response bit(RTE_DISTRIB_GET_BUF) of a received packet (d->bufs).
When the first packet arrives at rte_distributor_process(), the match value is 0.
And it is not enqueued in d->backlog nor in d->bufs    because the match value equals 0 .
The received first packet is never enqueued to d->bufs until the lcore_worker() returns the packet bufs (with the response bit(RTE_DISTRIB_GET_BUF) of bufs packet is set).
Since the lcore_worker cannot return packet if it cannot receive packet (Since the lcore_worker only reads the received packet with 0x0 flag).
It seems to be a deadlock.
Thus. first packet is never processed, I think.
Would you check this? 
Am I wrong? 
Does the lcore_worker() return packet even though it does not have received packet?
Thank you very much. 
Sincerely Yours,
Ick-Sung Choi.

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