From 94fcf0e85207979e3a7b35ad348cdd6b7ab42058 Mon Sep 17 00:00:00 2001 From: Victoria Dye Date: Thu, 10 Nov 2022 19:06:01 +0000 Subject: [PATCH] cache-tree: add perf test comparing update and prime MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a performance test comparing the execution times of 'prime_cache_tree()' and 'cache_tree_update(_, WRITE_TREE_SILENT | WRITE_TREE_REPAIR)'. The goal of comparing these two is to identify which is the faster method for rebuilding an invalid cache tree, ultimately to remove one when both are (reundantly) called in immediate succession. Both methods are fast, so the new tests in 'p0090-cache-tree.sh' must call each tested function multiple times to ensure the reported times (to 0.01s resolution) convey the differences between them. The tests compare the timing of a 'test-tool cache-tree' run as a no-op (to capture a baseline for the overhead associated with running the tool), 'cache_tree_update()', and 'prime_cache_tree()' on four scenarios: - A completely valid cache tree - A cache tree with 2 invalid paths - A cache tree with 50 invalid paths - A completely empty cache tree Example results: Test this tree ----------------------------------------------------------- 0090.2: no-op, clean 1.27(0.48+0.52) 0090.3: prime_cache_tree, clean 2.02(0.83+0.85) 0090.4: cache_tree_update, clean 1.30(0.49+0.54) 0090.5: no-op, invalidate 2 1.29(0.48+0.54) 0090.6: prime_cache_tree, invalidate 2 1.98(0.81+0.83) 0090.7: cache_tree_update, invalidate 2 2.12(0.94+0.86) 0090.8: no-op, invalidate 50 1.32(0.50+0.55) 0090.9: prime_cache_tree, invalidate 50 2.10(0.86+0.89) 0090.10: cache_tree_update, invalidate 50 2.35(1.14+0.90) 0090.11: no-op, empty 1.33(0.50+0.54) 0090.12: prime_cache_tree, empty 2.04(0.84+0.87) 0090.13: cache_tree_update, empty 2.51(1.27+0.92) These timings show that, while 'cache_tree_update()' is faster when the cache tree is completely valid, it is equal to or slower than 'prime_cache_tree()' when there are any invalid paths. Since the redundant calls are mostly in scenarios where the cache tree will be at least partially invalid (e.g., 'git reset --hard'), 'prime_cache_tree()' will likely perform better than 'cache_tree_update()' in typical cases. Helped-by: SZEDER Gábor Signed-off-by: Victoria Dye Signed-off-by: Taylor Blau --- Makefile | 1 + t/helper/test-cache-tree.c | 64 ++++++++++++++++++++++++++++++++++++++ t/helper/test-tool.c | 1 + t/helper/test-tool.h | 1 + t/perf/p0090-cache-tree.sh | 36 +++++++++++++++++++++ 5 files changed, 103 insertions(+) create mode 100644 t/helper/test-cache-tree.c create mode 100755 t/perf/p0090-cache-tree.sh diff --git a/Makefile b/Makefile index 4927379184..3639c7c2a9 100644 --- a/Makefile +++ b/Makefile @@ -723,6 +723,7 @@ TEST_BUILTINS_OBJS += test-advise.o TEST_BUILTINS_OBJS += test-bitmap.o TEST_BUILTINS_OBJS += test-bloom.o TEST_BUILTINS_OBJS += test-bundle-uri.o +TEST_BUILTINS_OBJS += test-cache-tree.o TEST_BUILTINS_OBJS += test-chmtime.o TEST_BUILTINS_OBJS += test-config.o TEST_BUILTINS_OBJS += test-crontab.o diff --git a/t/helper/test-cache-tree.c b/t/helper/test-cache-tree.c new file mode 100644 index 0000000000..93051b25f5 --- /dev/null +++ b/t/helper/test-cache-tree.c @@ -0,0 +1,64 @@ +#include "test-tool.h" +#include "cache.h" +#include "tree.h" +#include "cache-tree.h" +#include "parse-options.h" + +static char const * const test_cache_tree_usage[] = { + N_("test-tool cache-tree (control|prime|update)"), + NULL +}; + +int cmd__cache_tree(int argc, const char **argv) +{ + struct object_id oid; + struct tree *tree; + int empty = 0; + int invalidate_qty = 0; + int i; + + struct option options[] = { + OPT_BOOL(0, "empty", &empty, + N_("clear the cache tree before each iteration")), + OPT_INTEGER_F(0, "invalidate", &invalidate_qty, + N_("number of entries in the cache tree to invalidate (default 0)"), + PARSE_OPT_NONEG), + OPT_END() + }; + + setup_git_directory(); + + argc = parse_options(argc, argv, NULL, options, test_cache_tree_usage, 0); + + if (read_cache() < 0) + die(_("unable to read index file")); + + oidcpy(&oid, &the_index.cache_tree->oid); + tree = parse_tree_indirect(&oid); + if (!tree) + die(_("not a tree object: %s"), oid_to_hex(&oid)); + + if (empty) { + /* clear the cache tree & allocate a new one */ + cache_tree_free(&the_index.cache_tree); + the_index.cache_tree = cache_tree(); + } else if (invalidate_qty) { + /* invalidate the specified number of unique paths */ + float f_interval = (float)the_index.cache_nr / invalidate_qty; + int interval = f_interval < 1.0 ? 1 : (int)f_interval; + for (i = 0; i < invalidate_qty && i * interval < the_index.cache_nr; i++) + cache_tree_invalidate_path(&the_index, the_index.cache[i * interval]->name); + } + + if (argc != 1) + usage_with_options(test_cache_tree_usage, options); + else if (!strcmp(argv[0], "prime")) + prime_cache_tree(the_repository, &the_index, tree); + else if (!strcmp(argv[0], "update")) + cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR); + /* use "control" subcommand to specify no-op */ + else if (!!strcmp(argv[0], "control")) + die(_("Unhandled subcommand '%s'"), argv[0]); + + return 0; +} diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c index 01cda9358d..547a3be1c8 100644 --- a/t/helper/test-tool.c +++ b/t/helper/test-tool.c @@ -14,6 +14,7 @@ static struct test_cmd cmds[] = { { "bitmap", cmd__bitmap }, { "bloom", cmd__bloom }, { "bundle-uri", cmd__bundle_uri }, + { "cache-tree", cmd__cache_tree }, { "chmtime", cmd__chmtime }, { "config", cmd__config }, { "crontab", cmd__crontab }, diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h index ca2948066f..e44e1d896d 100644 --- a/t/helper/test-tool.h +++ b/t/helper/test-tool.h @@ -8,6 +8,7 @@ int cmd__advise_if_enabled(int argc, const char **argv); int cmd__bitmap(int argc, const char **argv); int cmd__bloom(int argc, const char **argv); int cmd__bundle_uri(int argc, const char **argv); +int cmd__cache_tree(int argc, const char **argv); int cmd__chmtime(int argc, const char **argv); int cmd__config(int argc, const char **argv); int cmd__crontab(int argc, const char **argv); diff --git a/t/perf/p0090-cache-tree.sh b/t/perf/p0090-cache-tree.sh new file mode 100755 index 0000000000..a8eabca2c4 --- /dev/null +++ b/t/perf/p0090-cache-tree.sh @@ -0,0 +1,36 @@ +#!/bin/sh + +test_description="Tests performance of cache tree update operations" + +. ./perf-lib.sh + +test_perf_large_repo +test_checkout_worktree + +count=100 + +test_expect_success 'setup cache tree' ' + git write-tree +' + +test_cache_tree () { + test_perf "$1, $3" " + for i in \$(test_seq $count) + do + test-tool cache-tree $4 $2 + done + " +} + +test_cache_tree_update_functions () { + test_cache_tree 'no-op' 'control' "$1" "$2" + test_cache_tree 'prime_cache_tree' 'prime' "$1" "$2" + test_cache_tree 'cache_tree_update' 'update' "$1" "$2" +} + +test_cache_tree_update_functions "clean" "" +test_cache_tree_update_functions "invalidate 2" "--invalidate 2" +test_cache_tree_update_functions "invalidate 50" "--invalidate 50" +test_cache_tree_update_functions "empty" "--empty" + +test_done