Merge pull request #160: trace2:gvfs:experiment Add experimental regions and data events to help diagnose checkout and reset perf problems

Add experimental regions and data events to help diagnose
performance problems in checkout and reset.

We may or may not choose to carry these changes forward in the future.

Author: derrickstolee

builtin/checkout.c

@@ -25,6 +25,7 @@
 #include "submodule-config.h"
 #include "submodule.h"
 #include "advice.h"
+#include "packfile.h"
 
 static int checkout_optimize_new_branch;
 
@@ -921,8 +922,13 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
 	strbuf_release(&msg);
 	if (!opts->quiet &&
 	    (new_branch_info->path || (!opts->force_detach && !strcmp(new_branch_info->name, "HEAD")))) {
+		unsigned long nr_unpack_entry_at_start;
+
 		trace2_region_enter("exp", "report_tracking", the_repository);
+		nr_unpack_entry_at_start = get_nr_unpack_entry();
 		report_tracking(new_branch_info);
+		trace2_data_intmax("exp", NULL, "report_tracking/nr_unpack_entries",
+				   (intmax_t)(get_nr_unpack_entry() - nr_unpack_entry_at_start));
 		trace2_region_leave("exp", "report_tracking", the_repository);
 	}
 }

cache-tree.c

@@ -221,20 +221,31 @@ static void discard_unused_subtrees(struct cache_tree *it)
 	}
 }
 
-int cache_tree_fully_valid(struct cache_tree *it)
+static int cache_tree_fully_valid_1(struct cache_tree *it)
 {
 	int i;
 	if (!it)
 		return 0;
 	if (it->entry_count < 0 || !has_object_file(&it->oid))
 		return 0;
 	for (i = 0; i < it->subtree_nr; i++) {
-		if (!cache_tree_fully_valid(it->down[i]->cache_tree))
+		if (!cache_tree_fully_valid_1(it->down[i]->cache_tree))
 			return 0;
 	}
 	return 1;
 }
 
+int cache_tree_fully_valid(struct cache_tree *it)
+{
+	int result;
+
+	trace2_region_enter("cache_tree", "fully_valid", NULL);
+	result = cache_tree_fully_valid_1(it);
+	trace2_region_leave("cache_tree", "fully_valid", NULL);
+
+	return result;
+}
+
 static int update_one(struct cache_tree *it,
 		      struct cache_entry **cache,
 		      int entries,

packfile.c

@@ -1646,6 +1646,13 @@ static void *read_object(struct repository *r,
 	return content;
 }
 
+static unsigned long g_nr_unpack_entry;
+
+unsigned long get_nr_unpack_entry(void)
+{
+	return g_nr_unpack_entry;
+}
+
 void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
 		   enum object_type *final_type, unsigned long *final_size)
 {
@@ -1659,6 +1666,8 @@ void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
 	int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
 	int base_from_cache = 0;
 
+	g_nr_unpack_entry++;
+
 	write_pack_access_log(p, obj_offset);
 
 	/* PHASE 1: drill down to the innermost base object */

packfile.h

@@ -193,4 +193,9 @@ int is_promisor_object(const struct object_id *oid);
 int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
 	     size_t idx_size, struct packed_git *p);
 
+/*
+ * Return the number of objects fetched from a packfile.
+ */
+unsigned long get_nr_unpack_entry(void);
+
 #endif

unpack-trees.c

@@ -19,6 +19,7 @@
 #include "fetch-object.h"
 #include "gvfs.h"
 #include "virtualfilesystem.h"
+#include "packfile.h"
 
 /*
  * Error messages expected by scripts out of plumbing commands such as
@@ -1474,10 +1475,14 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	int i, ret;
 	static struct cache_entry *dfc;
 	struct exclude_list el;
+	unsigned long nr_unpack_entry_at_start;
 
 	if (len > MAX_UNPACK_TREES)
 		die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
 
+	trace2_region_enter("exp", "unpack_trees", NULL);
+	nr_unpack_entry_at_start = get_nr_unpack_entry();
+
 	trace_performance_enter();
 	memset(&el, 0, sizeof(el));
 	if (!core_apply_sparse_checkout || !o->update)
@@ -1658,6 +1663,9 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 done:
 	trace_performance_leave("unpack_trees");
 	clear_exclude_list(&el);
+	trace2_data_intmax("exp", NULL, "unpack_trees/nr_unpack_entries",
+			   (intmax_t)(get_nr_unpack_entry() - nr_unpack_entry_at_start));
+	trace2_region_leave("exp", "unpack_trees", NULL);
 	return ret;
 
 return_failed:

virtualfilesystem.c

@@ -259,6 +259,8 @@ void apply_virtualfilesystem(struct index_state *istate)
 	if (!git_config_get_virtualfilesystem())
 		return;
 
+	trace2_region_enter("vfs", "apply", the_repository);
+
 	if (!virtual_filesystem_data.len)
 		get_virtual_filesystem_data(&virtual_filesystem_data);
 
@@ -329,6 +331,8 @@ void apply_virtualfilesystem(struct index_state *istate)
 		trace2_data_intmax("vfs", the_repository, "apply/nr_bulk_skip", nr_bulk_skip);
 		trace2_data_intmax("vfs", the_repository, "apply/nr_explicit_skip", nr_explicit_skip);
 	}
+
+	trace2_region_leave("vfs", "apply", the_repository);
 }
 
 /*