<div class="__aliyun_email_body_block"><div  style="font-family: Tahoma, Arial, STHeitiSC-Light, SimSun"><div  style="clear: both; font-family: Tahoma, Arial, STHeitiSC-Light, SimSun;"><span  style="font-family: Tahoma, Arial, STHeitiSC-Light, SimSun;">Hi <span  style="color: rgb(0, 0, 0); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">Stephen,</span></span></div><div  style="clear: both; font-family: Tahoma, Arial, STHeitiSC-Light, SimSun;"><span  style="font-family: Tahoma, Arial, STHeitiSC-Light, SimSun;"><br ></span></div><div  style="clear: both;"><span  style="font-family: Tahoma, Arial, STHeitiSC-Light, SimSun; color: rgb(0, 176, 80); font-style: italic;"><span  style="font-style: italic; color: rgb(0, 176, 80); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">> + while (true) {</span><br  style="font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><span  style="font-style: italic; color: rgb(0, 176, 80); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">> +  if (rte_bitmap_get(chan_info->mailbox.state_bmp, NBL_CHAN_INTERRUPT_READY)) {</span><br  style="font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><span  style="font-style: italic; color: rgb(0, 176, 80); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">> +   nr = <span  style="font-style: italic; font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; color: rgb(255, 0, 0); display: inline !important;">read(chan_info->mailbox.fd[0], &unused, sizeof(unused));</span></span><br  style="font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><span  style="font-style: italic; color: rgb(0, 176, 80); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">> +   if (nr < 0)</span><br  style="font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><span  style="font-style: italic; color: rgb(0, 176, 80); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">> +    break;</span><br  style="font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><span  style="font-style: italic; color: rgb(0, 176, 80); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">> +  }</span><br  style="font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><span  style="font-style: italic; color: rgb(0, 176, 80); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">> +  nbl_chan_clean_queue(chan_mgt);</span><br  style="font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><span  style="font-style: italic; color: rgb(0, 176, 80); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">> +  nanosleep(&time, 0);</span><br  style="font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><span  style="font-style: italic; color: rgb(0, 176, 80); font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; float: none; display: inline !important;">> + }</span></span></div><div  style="clear: both; font-family: Tahoma, Arial, STHeitiSC-Light, SimSun;"><span ><br ></span></div><div  style="clear: both; font-family: Tahoma, Arial, STHeitiSC-Light, SimSun;"><span >The chan_info->mailbox.fd[0] is the read fd of eventfd. We are using the eventfd block waiting to read mailbox message.</span></div><div  style="clear: both; font-family: Tahoma, Arial, STHeitiSC-Light, SimSun;"><span ><br ></span></div><div  style="clear: both; font-family: Tahoma, Arial, STHeitiSC-Light, SimSun;"><span >Thank you.</span></div><div  style="clear: both; font-family: Tahoma, Arial, STHeitiSC-Light, SimSun;"><span ><br ></span></div><blockquote  _quote="1" style="margin-right: 0px; margin-top: 0px; margin-bottom: 0px; font-family: Tahoma, Arial, STHeiti, SimSun; font-size: 14px; color: rgb(0, 0, 0);"><div  class="alimail-quote"><div  style="clear: both;">------------------------------------------------------------------</div><div  style="clear: both;">发件人：Stephen Hemminger <stephen@networkplumber.org></div><div  style="clear: both;">发送时间：2025年8月21日(周四) 00:16</div><div  style="clear: both;">收件人：Dimon<dimon.zhao@nebula-matrix.com></div><div  style="clear: both;">抄　送：dev<dev@dpdk.org>; Kyo Liu<kyo.liu@nebula-matrix.com>; Leon<leon.yu@nebula-matrix.com>; Sam<sam.chen@nebula-matrix.com></div><div  style="clear: both;">主　题：Re: [PATCH v5 04/17] net/nbl: add Channel layer definitions and implementation</div><div  style="clear: both;"><br ></div>On Tue, 19 Aug 2025 03:22:24 -0700<br >Dimon Zhao <dimon.zhao@nebula-matrix.com> wrote:<br ><br >> +<br >> +static uint32_t nbl_chan_thread_polling_task(void *param)<br >> +{<br >> + struct nbl_channel_mgt *chan_mgt = (struct nbl_channel_mgt *)param;<br >> + union nbl_chan_info *chan_info = NBL_CHAN_MGT_TO_CHAN_INFO(chan_mgt);<br >> + struct timespec time;<br >> + char unused[16];<br >> + ssize_t nr = 0;<br >> +<br >> + time.tv_sec = 0;<br >> + time.tv_nsec = 100000;<br >> +<br >> + while (true) {<br >> +  if (rte_bitmap_get(chan_info->mailbox.state_bmp, NBL_CHAN_INTERRUPT_READY)) {<br >> +   nr = read(chan_info->mailbox.fd[0], &unused, sizeof(unused));<br >> +   if (nr < 0)<br >> +    break;<br >> +  }<br >> +  nbl_chan_clean_queue(chan_mgt);<br >> +  nanosleep(&time, 0);<br >> + }<br >> +<br >> + return 0;<br >> +}<br ><br >This is going to make embedded application developers upset because it uses<br >a significant part of a CPU polling.<br ><br >Since you are reading from mailbox, why not implement select/poll/epoll and<br >have the thread block waiting to read mailbox instead.</div></blockquote><div  style="line-height: 20px; clear: both;"><br ></div></div></div>
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