Opened 7 years ago

Closed 15 months ago

#1747 closed bug (wontfix)

debugger: :trace is wasting time

Reported by: simonmar Owned by:
Priority: lowest Milestone: 7.6.2
Component: GHCi Version: 6.6.1
Keywords: Cc:
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: Compile-time performance bug Difficulty: Unknown
Test Case: Blocked By:
Blocking: Related Tickets:

Description (last modified by simonmar)

When using :trace, execution is constantly switching between the main GHCi thread and the execution thread. The main GHCi thread is a bound thread, whereas the other thread is an unbound thread, so these context switches are real OS-thread switches, consequently :trace wastes a lot of time context-switching.

Perhaps the main GHCi thread should be an unbound thread, or else :trace should fork an unbound thread before starting execution.

Change History (17)

comment:1 Changed 7 years ago by simonmar

  • Description modified (diff)

comment:2 Changed 6 years ago by simonmar

  • Milestone changed from 6.8 branch to 6.8.3

comment:3 Changed 6 years ago by simonmar

  • Type changed from bug to compile-time performance bug

comment:4 Changed 6 years ago by igloo

  • Milestone changed from 6.8.3 to 6.10.1

comment:5 Changed 6 years ago by simonmar

  • Architecture changed from Unknown to Unknown/Multiple

comment:6 Changed 6 years ago by simonmar

  • Operating System changed from Unknown to Unknown/Multiple

comment:7 Changed 6 years ago by igloo

  • Milestone changed from 6.10.1 to 6.12 branch
  • Priority changed from low to normal

comment:8 Changed 4 years ago by simonmar

  • Type of failure set to Compile-time performance bug

comment:9 Changed 4 years ago by igloo

  • Milestone changed from 6.12 branch to 6.12.3

comment:10 Changed 4 years ago by igloo

  • Milestone changed from 6.12.3 to 6.14.1
  • Priority changed from normal to low

comment:11 Changed 3 years ago by igloo

  • Milestone changed from 7.0.1 to 7.0.2

comment:12 Changed 3 years ago by igloo

  • Milestone changed from 7.0.2 to 7.2.1

comment:13 Changed 3 years ago by igloo

  • Milestone changed from 7.2.1 to 7.4.1

comment:14 Changed 2 years ago by igloo

  • Milestone changed from 7.4.1 to 7.6.1
  • Priority changed from low to lowest

comment:15 Changed 19 months ago by igloo

  • Milestone changed from 7.6.1 to 7.6.2

comment:16 Changed 15 months ago by morabbin

Bump; still relevant? BTW: this has no comments of substance, only component changes.

comment:17 Changed 15 months ago by simonmar

  • Resolution set to wontfix
  • Status changed from new to closed

Not much to be gained by having this ticket open, so I'll close it.

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