Widen epoch coverage (step 2) + refactor PCB info locking (step 2).
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Authored by glebius on Jan 15 2020, 3:12 AM.

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None

Group Reviewers

network
transport

Commits

rS356983: Make in_pcbladdr() require network epoch entered by its callers. Together

Summary

This patch extends network epoch coverage on output path. Now
calling ip_output() and ip6_output() requires epoch. This
eliminates a bunch of epoch recursions, and what is important
it eliminates ALL epoch recursions happening on the fast path:
forwarding, TCP in/out, UDP in/out.

It also relaxes assertions in PCB lookup functions, since now
ipi_lock is almost unused, we rely on ipi_list_lock/ipi_hash_lock
for modifications and on the epoch for lookups.

The above two changes are somewhat tied together, thus a single
review. The commit plan is 14 commits, full history available
here:

https://github.com/glebius/FreeBSD/commits/net_epoch2

Diff Detail

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Lint Passed

Unit

No Test Coverage

Build Status

Buildable 28839
Build 26847: arc lint + arc unit

Event Timeline

glebius created this revision.Jan 15 2020, 3:12 AM

Herald added 1 blocking reviewer(s): transport. · View Herald TranscriptJan 15 2020, 3:12 AM

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Harbormaster completed remote builds in B28677: Diff 66766.Jan 15 2020, 3:12 AM

Hi Glebius, I have a patch which tried to remove recursions within netinet6. I was down to one in December and since new ones have shown up. I am not sure if I'll be able to look at this one before next week but I'll try to upload my current work in progress in case that'll help you. I have EPOCH calls around all ip6_output() calls which this one equally adds, so most of my changes should be "downstream" from yours.

I'd really appreciate some reviewing. I'm going to commit this week.

Rebase to fresh master.

Harbormaster completed remote builds in B28839: Diff 67134.Jan 22 2020, 3:15 AM

This revision was not accepted when it landed; it landed in state Needs Review.Jan 22 2020, 6:11 AM

Closed by commit rS356983: Make in_pcbladdr() require network epoch entered by its callers. Together (authored by glebius). · Explain Why

This revision was automatically updated to reflect the committed changes.

glebius added a commit: rS356983: Make in_pcbladdr() require network epoch entered by its callers. Together.

Herald added a subscriber: imp. · View Herald TranscriptJan 22 2020, 6:11 AM