1 main thread + 2 work thread
------------------ Original ------------------
From: "wang.hui56"<wang.hu...@zte.com.cn>;
Date: Thu, Jun 22, 2017 03:06 PM
To: "fortitude.zhang"<fortitude.zh...@gmail.com>;
Cc: "leiyanzhang"<leiyanzh...@raydonetworks.com>;
"vpp-dev"<vpp-dev@lists.fd.io>;
Subject: 答复：Re: [vpp-dev] 答复: 【vpp-dev】delay is error in ping with multi
worker thread
stage2, how many your worker threads?
i remembered it is normal when 1main thread+1 worker thread.
发自我的zMail
原始邮件
发件人: 张东亚;
收件人:雷彦章;
抄送:王辉10067165; vpp-dev;
日期: 2017-06-22 11:09:18
主题:Re: [vpp-dev] 答复: 【vpp-dev】delay is error in ping with multi
worker thread
Hi List,
I am colleague of Leiyanzhang, let me describe share the issues and
investigations found when we test the ping command under multiple worker thread
case.
Stage1:
Issue: Ping does not work under multiple worker thread case.
Version: Vanilla vpp 17.04
(vanilla vp)
Stage2:
Issue: Ping got > 1s delay result under multiple worker thread case,
1s is the default ping interval, if we specify 10s interval, the delay will be
10s delay.
Version: Vanilla vpp 17.04 + VPP-844 patch.
Our Solution:
as Lei pointed out, we think it's not correct for the worker thread
to directly using the ping_run_t's cli_process_id to notify the main thread
because the vlib_process_signal_event is using work thread vlib_main structure,
however since process is shared by main thread and worker, when cli process in
main thread timeout waiting event, it can still fetch the event, but the delay
will be the interval.
State3:
Issue: Ping delay is not related with interval, but got 10ms+ delay
randomly.
Version: Vanilla vpp 17.04 + VPP-844 Patch + change to using
vl_api_rpc_call_main_thread to notify cli process in main thread.
Our solution:
After read vpp code, we think worker thread should use
vl_api_rpc_call_main_thread to notify cli process in main thread, after will
made the fix, the ping command works as expected most time with only random
10ms+ delay.
For this problem, we found the reason is related to
vl_api_rpc_call_main_thread only put then event to master thread
vl_input_queue, but does not notify and wake up master thread timely, the main
thread can only process this when linux_epoll_input returns, while it
will randomly sleep 10e3, if we change this value, the random ping delay will
change too.
We want to hear feedback from the list and hope we can find a better
way to fix this._______________________________________________
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