Differential D42860

kern/subr_trap.c: repair the HPTS performance hack in userret()
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Authored by glebius on Nov 30 2023, 10:18 PM.

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Reviewers

tuexen
rrs

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Commits

rG01df384133a3: kern/subr_trap.c: repair the HPTS performance hack in userret()
rGe3cbc572f154: kern/subr_trap.c: repair the HPTS performance hack in userret()

Summary

It wasn't functional as subr_trap.c doesn't include opt_inet.h. Put a
better comment in place of the old one. The idea is to use userret() as
a cheap place to call a soft clock. This approach saves CPU on busy
machines and saves power on idle machines. An alternative would be to
constantly schedule callouts. Running with neither callouts nor the soft
clock ruins HPTS precision.

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Repository

rG FreeBSD src repository

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Tests Not Applicable

Event Timeline

glebius created this revision.Nov 30 2023, 10:18 PM

Herald added 1 blocking reviewer(s): transport. · View Herald TranscriptNov 30 2023, 10:18 PM

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

glebius requested review of this revision.Nov 30 2023, 10:18 PM

Harbormaster completed remote builds in B54721: Diff 130882.Nov 30 2023, 10:18 PM

tuexen accepted this revision.Dec 1 2023, 7:49 PM

This revision is now accepted and ready to land.Dec 1 2023, 7:49 PM

rrs accepted this revision.Dec 4 2023, 5:04 PM

Closed by commit rGe3cbc572f154: kern/subr_trap.c: repair the HPTS performance hack in userret() (authored by glebius). · Explain WhyDec 4 2023, 7:00 PM

This revision was automatically updated to reflect the committed changes.

glebius added a commit: rGe3cbc572f154: kern/subr_trap.c: repair the HPTS performance hack in userret().

glebius added a commit: rG01df384133a3: kern/subr_trap.c: repair the HPTS performance hack in userret().Jan 16 2024, 7:06 PM

Revision Contents
Changeset List

Path

Size

sys/

kern/

20 lines

netinet/

1 line

4 lines

sys/

6 lines

Diff 131007

sys/kern/subr_trap.c

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sys/netinet/tcp_hpts.h

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sys/netinet/tcp_lro.c

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sys/sys/systm.h

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