move from 1.8G/core to 2.1

This is in response to several MueLu build failures
on full builds. Since this likely will relieve some
swapping it should help time on full builds or be a
wash. Might make small/medium builds a bit slower.

cmake/std/PullRequestLinuxDriver-Test.sh

@@ -349,11 +349,11 @@ weight=${JENKINS_JOB_WEIGHT:-29}
 n_cpu=$(lscpu | grep "^CPU(s):" | cut -d" " -f17)
 n_K=$(cat /proc/meminfo | grep MemTotal | cut -d" " -f8)
 let n_G=$n_K/1024000
-# this is aimed at keeping approximately 1.8G per core so we don't bottleneck
+# this is aimed at keeping approximately 2.1G per core so we don't bottleneck
 ## weight - the next bit works because the shell is only doing integer arithmetic
 let n_jobs=${n_cpu}/${weight}
 # using bc to get floating point input and integer output
-parallel_level=$(echo "$n_G/( 1.8*$n_jobs )" | bc )
+parallel_level=$(echo "$n_G/( 2.1*$n_jobs )" | bc )
 
 if [ ${parallel_level} -gt ${weight} ]; then
     parallel_level=${weight}