Manual:$wgUDPProfilerFormatString/en

Details
Format string for the UDP profiler. The UDP profiler invokes sprintf with (profile id, count, cpu, cpu_sq, real, real_sq, entry name, memory) as arguments. You can use sprintf's argument numbering/swapping capability to repeat, re-order or omit fields.

In MediaWiki 1.25 and later, set  instead.