markups

Author: ebeaty-cisco

README.md

@@ -47,6 +47,11 @@ packer build \
   -var 'tags={"mykey": "myvalue", "myotherkey": "myothervalue"}'
 ```
 
+Note that when building the AMI, the following warnings are expected and can be ignored:
+
+* When building the igb_uio driver, a warning for 'Skipping BTF generation' is expected. This doesn't affect the performance of the built driver.
+* When building TuneD, the 'desktop-file-install' action is expected to fail. This doesn't affect the installation of the tuned service.
+
 ## Using AMIs
 
 The AMIs produced by the template here require further configuration
@@ -70,7 +75,7 @@ Additionally, to ensure the worker node joins an EKS cluster, the normal
 EKS bootstrap script must be called.
 
 It's recommended to set this up in the User Data for the EC2 instance
-to ensure it's run on first boot. An example section fo this in a MIME
+to ensure it's run on first boot. An example section containing this in a MIME
 multi-part user-data is:
 
 ```bash
@@ -102,3 +107,5 @@ tuning steps:
   - Build, install, and activate the `igb_uio` interface driver kernel module.
   - Set up recommended core handling behavior.
   - Set up hugepage handling for systems with more than one NUMA node.
+
+Note that the TuneD bootloader plugin does not work in Amazon Linux 2023. The packer template matches the cmdline arguments set by the `realtime-virtual-guest` TuneD profile, in addition to the `default_hugepagesz`, `hugepagesz` and `hugepages` arguments.

amazon-ebs.pkr.hcl

@@ -26,10 +26,10 @@ variable "tags" {
 
 locals {
   default_tags = {
-    Generated_By         = "xrd-packer"
-    Kubernetes_Version   = var.kubernetes_version
-    Base_AMI_ID          = "{{ .SourceAMI }}"
-    Base_AMI_Name        = "{{ .SourceAMIName }}"
+    Generated_By       = "xrd-packer"
+    Kubernetes_Version = var.kubernetes_version
+    Base_AMI_ID        = "{{ .SourceAMI }}"
+    Base_AMI_Name      = "{{ .SourceAMIName }}"
   }
 }
 
@@ -45,7 +45,10 @@ source "amazon-ebs" "base" {
     owners      = ["amazon"]
 
     filters = {
-      name                = format("amazon-eks-node-al2023-x86_64-standard-%s-*", var.kubernetes_version)
+      name                = format(
+        "amazon-eks-node-al2023-x86_64-standard-%s-*",
+        var.kubernetes_version
+      )
       root-device-type    = "ebs"
       virtualization-type = "hvm"
     }

files/etc/xrd/bootstrap.sh

@@ -52,5 +52,9 @@ systemctl start hugetlb-gigantic-pages
 systemctl enable hugetlb-gigantic-pages
 
 # Add boot cmdline args
-non_isolated_cores=$(/etc/xrd/get_non_isolated_cores.sh $ISOLATED_CORES)
+# The below arguments are those that the `realtime-virtual-guest` TuneD profile
+# sets, in addition to the default_hugepagesz, hugepagesz and hugepages
+# arguments. These are set here as the TuneD bootloader plugin does not work
+# in the Amazon Linux 2023 image.
+non_isolated_cores=$(/etc/xrd/get_non_isolated_cores.py $ISOLATED_CORES)
 grubby --update-kernel ALL --args "nohz_full=${ISOLATED_CORES} nohz=on skew_tick=1 intel_pstate=disable tsc=reliable nosoftlockup isolcpus=${ISOLATED_CORES} irqaffinity=${non_isolated_cores} hugepages=${boot_hugepages} rcu_nocbs=${ISOLATED_CORES} hugepagesz=1G default_hugepagesz=1G rcupdate.rcu_normal_after_boot=1"

files/etc/xrd/get_non_isolated_cores.py

@@ -0,0 +1,59 @@
+#!/usr/bin/python3
+
+import os
+import sys
+
+def expand_range(range_str):
+    """Expand a range string like '2-4,6' into a list of integers."""
+    expanded = []
+    for part in range_str.split(','):
+        if '-' in part:
+            start, end = map(int, part.split('-'))
+            expanded.extend(range(start, end + 1))
+        else:
+            expanded.append(int(part))
+    return expanded
+
+def compress_to_range(cpu_list):
+    """Compress a list of integers into a range string like '2-4,6'."""
+    cpu_list = sorted(cpu_list)
+    ranges = []
+    start = cpu_list[0]
+    end = start
+
+    for i in range(1, len(cpu_list)):
+        if cpu_list[i] == end + 1:
+            end = cpu_list[i]
+        else:
+            if start == end:
+                ranges.append(str(start))
+            else:
+                ranges.append(f"{start}-{end}")
+            start = cpu_list[i]
+            end = start
+
+    if start == end:
+        ranges.append(str(start))
+    else:
+        ranges.append(f"{start}-{end}")
+
+    return ','.join(ranges)
+
+def exclude_cpus(exclude_set_str):
+    """Return a CPU set excluding the specified CPUs."""
+    all_cpus = set(range(os.cpu_count()))
+    exclude_cpus = set(expand_range(exclude_set_str))
+    included_cpus = sorted(all_cpus - exclude_cpus)
+    return compress_to_range(included_cpus)
+
+def main():
+    if len(sys.argv) < 2:
+        # No arguments provided, return all CPUs
+        all_cpus = list(range(os.cpu_count()))
+        print(compress_to_range(all_cpus))
+    else:
+        exclude_set_str = sys.argv[1]
+        print(exclude_cpus(exclude_set_str))
+
+if __name__ == "__main__":
+    main()

files/etc/xrd/get_non_isolated_cores.sh

@@ -4,7 +4,7 @@
 set -x
 
 # Download and build the igb_uio driver, and load it into the kernel.
-# N.B. A warning por 'Skipping BTF generation' is expected. This doesn't affect
+# N.B. A warning for 'Skipping BTF generation' is expected. This doesn't affect
 # the performance of the built driver.
 dnf install -y "kernel-devel-$(uname -r)"