circuit_unlink_all_from_orconn is too expensive

Moritz's relay spends a lot of time in circuit_unlink_all_from_orconn, which does a linear walk over the entire circuit list.

To make this faster, we'll need data structures. Currently, each or_connection has a doubly-linked list of its active circuits, but not of all its circuits. Adding such a doubly-linked-list is the obvious solution.

changed milestone to %Tor: unspecified

added component::core tor/tor easy milestone::Tor: unspecified points::small/medium priority::high resolution::wontfix severity::normal status::closed tor-relay type::defect labels

This was no longer a killer part of moritz's profiles last I looked. Still worth fixing, but not for 0.2.3.x

Trac:
Milestone: Tor: 0.2.3.x-final to Tor: 0.2.4.x-final

Trac:
Keywords: N/A deleted, easy added

Trac:
Keywords: easy deleted, easy tor-relay added

Trac:
Component: Tor Relay to Tor

Trac:
Milestone: Tor: 0.2.4.x-final to Tor: unspecified

Trac:
Username: marek

0001-Bug-4519-make-global_circuitlist-a-doubly-linked-lis.patch

Trac:
Username: marek

If we want to be able to unlink circuit_t without the need of walking through all of the circuits, first we need to make global_circuitlist a doubly-linked list. Attached patch does just that, and improves some other minor things:

• Doesn't expose global_circuitlist via 'extern', instead calls circuit_get_global_list_() to get the structure.
• Removes unused circuit_dump_by_chan and its helper circuit_dump_chan_details.
• Adds #include tor_queue.h to or.h as it's needed.

I don't think this patch is enough to "resolve" this bug, but is definitely necessary.

Trac:
Username: marek
Status: new to needs_review

Replying to marek:

If we want to be able to unlink circuit_t without the need of walking through all of the circuits, first we need to make global_circuitlist a doubly-linked list. Attached patch does just that, and improves some other minor things:

• Doesn't expose global_circuitlist via 'extern', instead calls circuit_get_global_list_() to get the structure.

This should be a separate commit/patch, before your other changes.

• Removes unused circuit_dump_by_chan and its helper circuit_dump_chan_details.

This should be not only a separate commit/patch, but a separate Trac ticket. (Perhaps the real bug here is that those functions are unused.)

• Adds #include tor_queue.h to or.h as it's needed.

I don't think this patch is enough to "resolve" this bug, but is definitely necessary.

Replying to rransom:

After reading the description of this bug again, I don't think my patch has much to do with it. Sorry. Let's move the discussion to #9107 (moved) and #9108 (moved) .

Trac:
Username: marek
Status: needs_review to new

Trac:
Points: N/A to small/medium
Sponsor: N/A to N/A
Severity: N/A to Normal

If it's not in profiles, let's not speed it up.

Trac:
Reviewer: N/A to N/A
Resolution: N/A to wontfix
Status: new to closed

closed

mentioned in issue #9107 (moved)

mentioned in issue #9108 (moved)

moved to tpo/core/tor#4519 (closed)

mentioned in issue tpo/core/tor#9107 (closed)

mentioned in issue tpo/core/tor#9108 (closed)