+ case 'lts-head':
+ // Keep only the head of each LTS branch and the latest non-RC tag
+ println('Filter kernel versions to keep only the latest point release of each lts branch and the current stable.')
+
+ def lts_kversions = []
+ // Old LTS entries are kept so that "lts-head" is still meaningful in kernel
+ // version ranges that are supported by lttng-modules but no longer supported
+ // upstream, eg. lttng-modules stable-2.13 supports >= 3.0
+ lts_kversions.add(kversionFactory.factory("v3.0")) // LTS until October 2013
+ lts_kversions.add(kversionFactory.factory("v3.2")) // LTS until May 2018
+ lts_kversions.add(kversionFactory.factory("v3.4")) // LTS until October 2016
+ lts_kversions.add(kversionFactory.factory("v3.10")) // LTS until November 2017
+ lts_kversions.add(kversionFactory.factory("v3.12")) // LTS until May 2017
+ lts_kversions.add(kversionFactory.factory("v3.14")) // LTS until August 2016
+ lts_kversions.add(kversionFactory.factory("v3.16")) // LTS until October 2014
+ lts_kversions.add(kversionFactory.factory("v3.18")) // LTS until January 2017
+ lts_kversions.add(kversionFactory.factory("v4.1")) // LTS until May 2018
+ lts_kversions.add(kversionFactory.factory("v4.4")) // SLTS until 2026
+ lts_kversions.add(kversionFactory.factory("v4.9")) // LTS until January 2023
+ lts_kversions.add(kversionFactory.factory("v4.14")) // LTS until January 2024
+ lts_kversions.add(kversionFactory.factory("v4.19")) // LTS until December 2024
+ lts_kversions.add(kversionFactory.factory("v5.4")) // LTS until December 2025
+ lts_kversions.add(kversionFactory.factory("v5.10")) // LTS until December 2026
+ lts_kversions.add(kversionFactory.factory("v5.15")) // LTS until December 2026
+ lts_kversions.add(kversionFactory.factory("v6.1")) // LTS until December 2026
+ lts_kversions.add(kversionFactory.factory("v6.6")) // LTS until December 2026
+
+ // First filter the head of each branch
+ for (i = 0; i < kversions.size(); i++) {
+ def curr = kversions[i]
+ def next = i < kversions.size() - 1 ? kversions[i + 1] : null
+
+ if (next != null) {
+ if (curr.isSameStable(next)) {
+ kversions.remove(i)
+ i--
+ }
+ }
+ }
+
+ for (i = 0; i < kversions.size(); i++) {
+ def curr = kversions[i]
+
+ // Keep the newest tag
+ if (i == kversions.size() - 1) {
+ break
+ }
+
+ // Prune non-LTS versions
+ def keep = false
+ for (j = 0; j < lts_kversions.size(); j++) {
+ if (curr.isSameStable(lts_kversions[j])) {
+ keep = true
+ break
+ }
+ }
+
+ if (!keep) {
+ kversions.remove(i)
+ i--
+ }
+ }
+ break
+