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Don't deref an mbuf ext_pgs pointer in tcp_m_copym() unless we need to
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Authored by gallatin on Mar 7 2020, 10:56 PM.

Details

Summary

Avoid a cache miss accessing an mbuf ext_pgs pointer when not doing hardware TLS.

For a Netflix 90Gb/s 100% TLS software TLS workload, this reduces the CPI of tcp_m_copym() from ~3.5 to ~2.5 as reported by vtune.

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Repository
rS FreeBSD src repository - subversion
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Automatic diff as part of commit; lint not applicable.
Unit
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