KiAbThreadUnboostIoPriority

void __fastcall KiAbThreadUnboostIoPriority(__int64 a1, int a2){
  _InterlockedDecrement((volatile signed __int32 *)((a2 != 0 ? 4 : 0) + a1 + 860));
  if( a2 )
    PsBoostThreadIoQoS(a1, 1);
  else
    PsBoostThreadIoEx(a1, 1, 0, 0i64);
}

Referenced by:

ExReleasePushLockEx
KeAbPostRelease
KiAbThreadRemoveBoosts