Switch Dawn builderful Linux-based trybots to builderless

Switches all Dawn builderful trybots which run on Linux GCEs to instead
be builderless in the luci.chromium.gpu.try pool. max_concurrent_builds
is set to the same value as the builderful pool size for each builder.

There should be sufficient spare capacity in the pool for this, as the
fewest number of idle Linux GCEs in the pool in the past week has been
27, and this should only add a max of 26 additional builds if every
builder is running its max number of allowed builds simultaneously.

Bug: 375244064
Change-Id: Ic258240d848e83929138b4e3624ddaee4016682f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6566090
Reviewed-by: Garrett Beaty <gbeaty@google.com>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1462873}

infra/config/generated/luci/cr-buildbucket.cfg

@@ -87985,10 +87985,12 @@ buckets {
     builders {
       name: "android-dawn-arm-rel"
       swarming_host: "chromium-swarm.appspot.com"
-      dimensions: "builder:android-dawn-arm-rel"
+      dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
+      dimensions: "free_space:standard"
       dimensions: "os:Ubuntu-22.04"
-      dimensions: "pool:luci.chromium.try"
+      dimensions: "pool:luci.chromium.gpu.try"
+      dimensions: "ssd:0"
       exe {
         cipd_package: "infra/chromium/bootstrapper/${platform}"
         cipd_version: "latest"
@@ -88090,6 +88092,7 @@ buckets {
         predicates: "has(build.output.properties.is_cached)"
         predicates: "string(build.output.properties.is_cached) == \"false\""
       }
+      max_concurrent_builds: 3
     }
     builders {
       name: "android-dawn-arm64-exp-rel"
@@ -88206,10 +88209,12 @@ buckets {
     builders {
       name: "android-dawn-arm64-rel"
       swarming_host: "chromium-swarm.appspot.com"
-      dimensions: "builder:android-dawn-arm64-rel"
+      dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
+      dimensions: "free_space:standard"
       dimensions: "os:Ubuntu-22.04"
-      dimensions: "pool:luci.chromium.try"
+      dimensions: "pool:luci.chromium.gpu.try"
+      dimensions: "ssd:0"
       exe {
         cipd_package: "infra/chromium/bootstrapper/${platform}"
         cipd_version: "latest"
@@ -88311,6 +88316,7 @@ buckets {
         predicates: "has(build.output.properties.is_cached)"
         predicates: "string(build.output.properties.is_cached) == \"false\""
       }
+      max_concurrent_builds: 3
     }
     builders {
       name: "android-dawn-arm64-s24-rel"
@@ -95045,10 +95051,12 @@ buckets {
     builders {
       name: "dawn-android-arm-deps-rel"
       swarming_host: "chromium-swarm.appspot.com"
-      dimensions: "builder:dawn-android-arm-deps-rel"
+      dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
+      dimensions: "free_space:standard"
       dimensions: "os:Ubuntu-22.04"
-      dimensions: "pool:luci.chromium.try"
+      dimensions: "pool:luci.chromium.gpu.try"
+      dimensions: "ssd:0"
       exe {
         cipd_package: "infra/chromium/bootstrapper/${platform}"
         cipd_version: "latest"
@@ -95151,14 +95159,17 @@ buckets {
         predicates: "has(build.output.properties.is_cached)"
         predicates: "string(build.output.properties.is_cached) == \"false\""
       }
+      max_concurrent_builds: 5
     }
     builders {
       name: "dawn-android-arm64-deps-rel"
       swarming_host: "chromium-swarm.appspot.com"
-      dimensions: "builder:dawn-android-arm64-deps-rel"
+      dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
+      dimensions: "free_space:standard"
       dimensions: "os:Ubuntu-22.04"
-      dimensions: "pool:luci.chromium.try"
+      dimensions: "pool:luci.chromium.gpu.try"
+      dimensions: "ssd:0"
       exe {
         cipd_package: "infra/chromium/bootstrapper/${platform}"
         cipd_version: "latest"
@@ -95261,14 +95272,17 @@ buckets {
         predicates: "has(build.output.properties.is_cached)"
         predicates: "string(build.output.properties.is_cached) == \"false\""
       }
+      max_concurrent_builds: 5
     }
     builders {
       name: "dawn-chromium-presubmit"
       swarming_host: "chromium-swarm.appspot.com"
-      dimensions: "builder:dawn-chromium-presubmit"
+      dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
+      dimensions: "free_space:standard"
       dimensions: "os:Ubuntu-22.04"
-      dimensions: "pool:luci.chromium.try"
+      dimensions: "pool:luci.chromium.gpu.try"
+      dimensions: "ssd:0"
       exe {
         cipd_package: "infra/chromium/bootstrapper/${platform}"
         cipd_version: "latest"
@@ -95370,14 +95384,17 @@ buckets {
         predicates: "has(build.output.properties.is_cached)"
         predicates: "string(build.output.properties.is_cached) == \"false\""
       }
+      max_concurrent_builds: 2
     }
     builders {
       name: "dawn-linux-x64-deps-rel"
       swarming_host: "chromium-swarm.appspot.com"
-      dimensions: "builder:dawn-linux-x64-deps-rel"
+      dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
+      dimensions: "free_space:standard"
       dimensions: "os:Ubuntu-22.04"
-      dimensions: "pool:luci.chromium.try"
+      dimensions: "pool:luci.chromium.gpu.try"
+      dimensions: "ssd:0"
       exe {
         cipd_package: "infra/chromium/bootstrapper/${platform}"
         cipd_version: "latest"
@@ -95480,6 +95497,7 @@ buckets {
         predicates: "has(build.output.properties.is_cached)"
         predicates: "string(build.output.properties.is_cached) == \"false\""
       }
+      max_concurrent_builds: 5
     }
     builders {
       name: "dawn-mac-arm64-deps-rel"
@@ -112784,10 +112802,12 @@ buckets {
     builders {
       name: "linux-dawn-rel"
       swarming_host: "chromium-swarm.appspot.com"
-      dimensions: "builder:linux-dawn-rel"
+      dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
+      dimensions: "free_space:standard"
       dimensions: "os:Ubuntu-22.04"
-      dimensions: "pool:luci.chromium.try"
+      dimensions: "pool:luci.chromium.gpu.try"
+      dimensions: "ssd:0"
       exe {
         cipd_package: "infra/chromium/bootstrapper/${platform}"
         cipd_version: "latest"
@@ -112889,6 +112909,7 @@ buckets {
         predicates: "has(build.output.properties.is_cached)"
         predicates: "string(build.output.properties.is_cached) == \"false\""
       }
+      max_concurrent_builds: 3
     }
     builders {
       name: "linux-dcheck-off-rel"

infra/config/subprojects/chromium/try/tryserver.chromium.dawn.star

@@ -52,8 +52,12 @@ try_.builder(
         retry_without_patch = False,
     ),
     gn_args = "ci/Dawn Chromium Presubmit",
+    pool = "luci.chromium.gpu.try",
+    builderless = True,
+    os = os.LINUX_DEFAULT,
     execution_timeout = 30 * time.minute,
     main_list_view = "try",
+    max_concurrent_builds = 2,
 )
 
 try_.builder(
@@ -64,7 +68,11 @@ try_.builder(
         "ci/Dawn Android arm DEPS Release (Pixel 4)",
     ],
     gn_args = "ci/Dawn Android arm DEPS Builder",
+    pool = "luci.chromium.gpu.try",
+    builderless = True,
+    os = os.LINUX_DEFAULT,
     main_list_view = "try",
+    max_concurrent_builds = 5,
     test_presentation = resultdb.test_presentation(
         grouping_keys = ["status", "v.test_suite", "v.gpu"],
     ),
@@ -92,7 +100,11 @@ try_.builder(
         "ci/Dawn Android arm64 DEPS Release (Pixel 6)",
     ],
     gn_args = "ci/Dawn Android arm64 DEPS Builder",
+    pool = "luci.chromium.gpu.try",
+    builderless = True,
+    os = os.LINUX_DEFAULT,
     main_list_view = "try",
+    max_concurrent_builds = 5,
     test_presentation = resultdb.test_presentation(
         grouping_keys = ["status", "v.test_suite", "v.gpu"],
     ),
@@ -123,7 +135,11 @@ try_.builder(
         "ci/Dawn Linux x64 DEPS Release (NVIDIA)",
     ],
     gn_args = "ci/Dawn Linux x64 DEPS Builder",
+    pool = "luci.chromium.gpu.try",
+    builderless = True,
+    os = os.LINUX_DEFAULT,
     main_list_view = "try",
+    max_concurrent_builds = 5,
     test_presentation = resultdb.test_presentation(
         grouping_keys = ["status", "v.test_suite", "v.gpu"],
     ),
@@ -309,6 +325,10 @@ try_.builder(
         "ci/Dawn Android arm Release (Pixel 4)",
     ],
     gn_args = "ci/Dawn Android arm Builder",
+    pool = "luci.chromium.gpu.try",
+    builderless = True,
+    os = os.LINUX_DEFAULT,
+    max_concurrent_builds = 3,
     test_presentation = resultdb.test_presentation(
         grouping_keys = ["status", "v.test_suite", "v.gpu"],
     ),
@@ -321,6 +341,10 @@ try_.builder(
         "ci/Dawn Android arm64 Release (Pixel 6)",
     ],
     gn_args = "ci/Dawn Android arm64 Builder",
+    pool = "luci.chromium.gpu.try",
+    builderless = True,
+    os = os.LINUX_DEFAULT,
+    max_concurrent_builds = 3,
     test_presentation = resultdb.test_presentation(
         grouping_keys = ["status", "v.test_suite", "v.gpu"],
     ),
@@ -404,6 +428,10 @@ try_.builder(
         "ci/Dawn Linux x64 Release (NVIDIA)",
     ],
     gn_args = "ci/Dawn Linux x64 Builder",
+    pool = "luci.chromium.gpu.try",
+    builderless = True,
+    os = os.LINUX_DEFAULT,
+    max_concurrent_builds = 3,
     test_presentation = resultdb.test_presentation(
         grouping_keys = ["status", "v.test_suite", "v.gpu"],
     ),