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<p class="MsoPlainText">Sorry, sent the previous email too quickly.<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">> -----Original Message-----<o:p></o:p></p>
<p class="MsoNormal">> From: Marat Khalili <o:p></o:p></p>
<p class="MsoNormal">> Sent: Thursday 31 July 2025 11:52<o:p></o:p></p>
<p class="MsoNormal">> To: '<span lang="ZH-CN" style="font-family:DengXian">苏赛</span>' <susai.ss@bytedance.com>; jasvinder.singh@intel.com<o:p></o:p></p>
<p class="MsoNormal">> Cc: dev@dpdk.org<o:p></o:p></p>
<p class="MsoNormal">> Subject: RE: [PATCH] net/cksum: compute raw cksum for several segments<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">> > +static inline uint16_t<o:p></o:p></p>
<p class="MsoNormal">> > +__rte_raw_cksum_reduce_u64(uint64_t sum)<o:p></o:p></p>
<p class="MsoNormal">> > +{<o:p></o:p></p>
<p class="MsoNormal">> > + uint32_t tmp;<o:p></o:p></p>
<p class="MsoNormal">> > +<o:p></o:p></p>
<p class="MsoNormal">> > + tmp = __rte_raw_cksum_reduce((uint32_t)sum);<o:p></o:p></p>
<p class="MsoNormal">> > + tmp += __rte_raw_cksum_reduce((uint32_t)(sum >> 32));<o:p></o:p></p>
<p class="MsoNormal">> <o:p></o:p></p>
<p class="MsoNormal">> What if this addition overflows?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Realized it cannot actually overflow, my bad (maybe still needs a comment). Now this function looks good to me as well.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">> > + return __rte_raw_cksum_reduce(tmp);<o:p></o:p></p>
<p class="MsoNormal">> > +}<o:p></o:p></p>
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