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| author | 2020-07-08 15:51:37 -0700 | |
|---|---|---|
| committer | 2020-07-08 15:51:37 -0700 | |
| commit | d417bf474f04f8a5a1e09b431abbd9bad9af4952 (patch) | |
| tree | 5081254a7973c51a216cb92125e8993f24e8dd05 /docs/perf.md | |
| parent | 0ae555df1a5b0fc86a6fa83c1de42026ef184cd2 (diff) | |
Document critical path in perf.md
Test: none
Change-Id: I7de9b98fea67084ec5b5ce5429f0a8f976341439
Diffstat (limited to 'docs/perf.md')
| -rw-r--r-- | docs/perf.md | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/docs/perf.md b/docs/perf.md index 538adffb5..86a27b43f 100644 --- a/docs/perf.md +++ b/docs/perf.md @@ -12,6 +12,41 @@ are stored in `soong.#.log` and `verbose.#.log.gz`.  +### Critical path + +soong_ui logs the wall time of the longest dependency chain compared to the +elapsed wall time in `$OUT_DIR/soong.log`. For example: +``` +critical path took 3m10s +elapsed time 5m16s +perfect parallelism ratio 60% +critical path: + 0:00 build out/target/product/generic_arm64/obj/FAKE/sepolicy_neverallows_intermediates/policy_2.conf + 0:04 build out/target/product/generic_arm64/obj/FAKE/sepolicy_neverallows_intermediates/sepolicy_neverallows + 0:13 build out/target/product/generic_arm64/obj/ETC/plat_sepolicy.cil_intermediates/plat_sepolicy.cil + 0:01 build out/target/product/generic_arm64/obj/ETC/plat_pub_versioned.cil_intermediates/plat_pub_versioned.cil + 0:02 build out/target/product/generic_arm64/obj/ETC/vendor_sepolicy.cil_intermediates/vendor_sepolicy.cil + 0:16 build out/target/product/generic_arm64/obj/ETC/sepolicy_intermediates/sepolicy + 0:00 build out/target/product/generic_arm64/obj/ETC/plat_seapp_contexts_intermediates/plat_seapp_contexts + 0:00 Install: out/target/product/generic_arm64/system/etc/selinux/plat_seapp_contexts + 0:02 build out/target/product/generic_arm64/obj/NOTICE.txt + 0:00 build out/target/product/generic_arm64/obj/NOTICE.xml.gz + 0:00 build out/target/product/generic_arm64/system/etc/NOTICE.xml.gz + 0:01 Installed file list: out/target/product/generic_arm64/installed-files.txt + 1:00 Target system fs image: out/target/product/generic_arm64/obj/PACKAGING/systemimage_intermediates/system.img + 0:01 Install system fs image: out/target/product/generic_arm64/system.img + 0:01 Target vbmeta image: out/target/product/generic_arm64/vbmeta.img + 1:26 Package target files: out/target/product/generic_arm64/obj/PACKAGING/target_files_intermediates/aosp_arm64-target_files-6663974.zip + 0:01 Package: out/target/product/generic_arm64/aosp_arm64-img-6663974.zip + 0:01 Dist: /buildbot/dist_dirs/aosp-master-linux-aosp_arm64-userdebug/6663974/aosp_arm64-img-6663974.zip +``` + +If the elapsed time is much longer than the critical path then additional +parallelism on the build machine will improve total build times. If there are +long individual times listed in the critical path then improving build times +for those steps or adjusting dependencies so that those steps can run earlier +in the build graph will improve total build times. + ### Soong Soong can be traced and profiled using the standard Go tools. It understands |