test/scheduler: Add wrapper for setting up the environment

Setup boils down to selecting CPUs for exclusive use by SPDK
app(s).

Signed-off-by: Michal Berger <michalx.berger@intel.com>
Change-Id: Ie3af44d16f3f220aeca97b2d65a99297016884dc
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5739
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Karol Latecki <karol.latecki@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

test/scheduler/isolate_cores.sh

@@ -0,0 +1,45 @@
+# Select cores for the test
+xtrace_disable
+
+source "$testdir/common.sh"
+
+# Number of cpus to include in the mask
+NUM_CPUS=${NUM_CPUS:-8}
+
+map_cpus
+
+# Build core mask. Avoid all CPUs that may be offline and skip cpu0
+# (and all its potential thread siblings) as it's already doing an
+# extra work for the kernel.
+denied_list $(get_cpus "${cpu_node_map[0]}" "${cpu_core_map[0]}")
+# If there are any isolated cpus (as defined on the kernel cmdline
+# with isolcpus) they take the priority. We fill up the list up to
+# NUM_CPUS, applying filtering as per the denied list. All cpus are
+# taken from node0.
+allowed_list "$NUM_CPUS" 0
+
+# Assign proper resources to the cpuset/spdk
+spdk_cpus=("${allowed[@]}")
+spdk_cpus_csv=$(fold_array_onto_string "${spdk_cpus[@]}")
+spdk_cpusmask=$(mask_cpus "${spdk_cpus[@]}")
+spdk_main_core=${spdk_cpus[0]}
+spdk_cpus_mems=0
+
+# Build list of remaining cpus for posterity
+denied_list "${spdk_cpus[@]}"
+fold_list_onto_array allowed "${cpus[@]}"
+filter_allowed_list
+
+all_cpus=("${allowed[@]}")
+all_cpus_csv=$(fold_array_onto_string "${all_cpus[@]}")
+all_cpusmask=$(mask_cpus "${all_cpus[@]}")
+
+export \
+	"spdk_cpusmask=$spdk_cpusmask" \
+	"spdk_cpus_csv=$spdk_cpus_csv" \
+	"spdk_cpus_no=${#spdk_cpus[@]}" \
+	"spdk_main_core=$spdk_main_core" \
+	"all_cpusmask=$all_cpusmask" \
+	"all_cpus_csv=$all_cpus_csv"
+
+xtrace_restore