Don't deref an mbuf ext_pgs pointer in tcp_m_copym() unless we need to
ClosedPublic
Actions

Authored by gallatin on Mar 7 2020, 10:56 PM.

Tags

None

Referenced Files

	Unknown Object (File)
	Dec 14 2025, 11:35 PM

	Unknown Object (File)
	Dec 14 2025, 12:41 PM

	Unknown Object (File)
	Nov 26 2025, 9:56 PM

	Unknown Object (File)
	Nov 23 2025, 1:11 AM

	Unknown Object (File)
	Nov 20 2025, 4:10 PM

	Unknown Object (File)
	Nov 20 2025, 4:07 PM

	Unknown Object (File)
	Nov 20 2025, 4:07 PM

	Unknown Object (File)
	Nov 20 2025, 3:57 PM

View All Files

Subscribers

imp

melifaro

Details

Reviewers

rrs
jhb
jtl

Group Reviewers

transport

Commits

rS359016: Avoid a cache miss accessing an mbuf ext_pgs pointer when doing SW kTLS.

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.

Diff Detail

Repository

rS FreeBSD src repository - subversion

Lint

Lint Not Applicable

Unit

Tests Not Applicable

Event Timeline

gallatin created this revision.Mar 7 2020, 10:56 PM

Herald added a reviewer: transport. · View Herald TranscriptMar 7 2020, 10:56 PM

Herald added subscribers: melifaro, imp. · View Herald Transcript

Harbormaster completed remote builds in B29843: Diff 69302.Mar 7 2020, 10:57 PM

rrs accepted this revision.Mar 8 2020, 4:14 PM

This revision is now accepted and ready to land.Mar 8 2020, 4:14 PM

jtl accepted this revision.Mar 9 2020, 4:25 PM

Closed by commit rS359016: Avoid a cache miss accessing an mbuf ext_pgs pointer when doing SW kTLS. (authored by gallatin). · Explain WhyMar 16 2020, 2:03 PM

This revision was automatically updated to reflect the committed changes.

gallatin added a commit: rS359016: Avoid a cache miss accessing an mbuf ext_pgs pointer when doing SW kTLS..

Revision Contents
Changeset List

Path

Size

head/

sys/

netinet/

tcp_output.c

2 lines

Diff 69568

View Options

head/sys/netinet/tcp_output.c

Don't deref an mbuf ext_pgs pointer in tcp_m_copym() unless we need toClosedPublicActions