Opened 10 years ago

Last modified 4 years ago

#3462 new task

New codegen: allocate large objects using allocateLocal()

Reported by: simonmar Owned by: simonmar
Priority: low Milestone:
Component: Runtime System Version: 6.11
Keywords: Cc: simonmar
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: Runtime performance bug Test Case:
Blocked By: #4258 Blocking:
Related Tickets: Differential Rev(s):
Wiki Page:


See #3424.

In the new code generator, we should allocate large objects (larger than F * block size, for some suitable fraction F) using the RTS allocateLocal() API rather than from the nursery. It works to allocate them from the nursery -- this is what GHC 6.12 does after the fix in #3424 -- but then they will not be treated as large objects and will be copied during GC. Also, the allocation is likely to fail, requiring a trip through the RTS to put a large enough block in the nursery to satisfy the allocation.

Change History (8)

comment:1 Changed 9 years ago by igloo

Blocked By: 4258 added
Type of failure: None/Unknown

comment:2 Changed 8 years ago by igloo

Priority: normallow

comment:3 Changed 7 years ago by igloo


comment:4 Changed 5 years ago by thoughtpolice


Moving to 7.10.1.

comment:5 Changed 5 years ago by thomie

Cc: simonmar added
Component: CompilerRuntime System
Owner: set to simonmar
Type of failure: None/UnknownRuntime performance bug

Commit 5270423a6afe69f1dc57e5e5a474812182718d40:

Author: Simon Marlow <>
Date:   Tue Dec 1 16:03:21 2009 +0000


      - allocateLocal() now allocates large objects into the local
        nursery, rather than taking a global lock and allocating
        then in gen 0 step 0.
      - I removed the global allocate() function, and renamed
        allocateLocal() to allocate().


comment:6 Changed 5 years ago by thoughtpolice


Moving to 7.12.1 milestone; if you feel this is an error and should be addressed sooner, please move it back to the 7.10.1 milestone.

comment:7 Changed 4 years ago by thoughtpolice


Milestone renamed

comment:8 Changed 4 years ago by thomie

Milestone: 8.0.1
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