[IMPALA-12807] Add option to use the 'mold' linker

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 4.3.0
• Fix Version/s: Impala 4.3.0
• Component/s: Backend
• Epic Color: ghx-label-2
• Assignee: Joe McDonnell
• Reporter: Joe McDonnell
• Created: 10/Feb/24 00:03
• Updated: 16/Jul/24 23:10
• Resolved: 25/Mar/24 22:57

Description

Mold is a new linker that says it is faster than lld and gold. See https://github.com/rui314/mold

Hand testing it on my machine, it makes a big difference in speed of iteration:

# Test case:
#  - Start with fully built impalad
#  - touch be/src/scheduling/scheduler.cc 
#  - time make -j12 impalad

With Gold (current default):

real    0m15.843s
user    0m15.478s
sys     0m2.127s

real    0m15.820s
user    0m15.302s
sys     0m2.157s

real    0m16.136s
user    0m15.799s
sys     0m2.098s

With Mold:

real    0m2.479s
user    0m2.169s
sys     0m0.958s

real    0m2.674s
user    0m2.218s
sys     0m1.086s

real    0m2.524s
user    0m2.136s
sys     0m1.042s

This seems like something we should investigate further.