Merge branch 'en/ort-perf-batch-15'

Final batch for "merge -sort" optimization.

* en/ort-perf-batch-15:
  merge-ort: remove compile-time ability to turn off usage of memory pools
  merge-ort: reuse path strings in pool_alloc_filespec
  merge-ort: store filepairs and filespecs in our mem_pool
  diffcore-rename, merge-ort: add wrapper functions for filepair alloc/dealloc
  merge-ort: switch our strmaps over to using memory pools
  merge-ort: set up a memory pool
  merge-ort: add pool_alloc, pool_calloc, and pool_strndup wrappers
  diffcore-rename: use a mem_pool for exact rename detection's hashmap
  merge-ort: rename str{map,intmap,set}_func()

3 files changed, 165 insertions, 94 deletions

diff --git a/diffcore-rename.c b/diffcore-rename.c
index c95857b51f..bebd4ed6a4 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -317,10 +317,11 @@ static int find_identical_files(struct hashmap *srcs,
 }
 
 static void insert_file_table(struct repository *r,
+			      struct mem_pool *pool,
 			      struct hashmap *table, int index,
 			      struct diff_filespec *filespec)
 {
-	struct file_similarity *entry = xmalloc(sizeof(*entry));
+	struct file_similarity *entry = mem_pool_alloc(pool, sizeof(*entry));
 
 	entry->index = index;
 	entry->filespec = filespec;
@@ -336,7 +337,8 @@ static void insert_file_table(struct repository *r,
  * and then during the second round we try to match
  * cache-dirty entries as well.
  */
-static int find_exact_renames(struct diff_options *options)
+static int find_exact_renames(struct diff_options *options,
+			      struct mem_pool *pool)
 {
 	int i, renames = 0;
 	struct hashmap file_table;
@@ -346,7 +348,7 @@ static int find_exact_renames(struct diff_options *options)
 	 */
 	hashmap_init(&file_table, NULL, NULL, rename_src_nr);
 	for (i = rename_src_nr-1; i >= 0; i--)
-		insert_file_table(options->repo,
+		insert_file_table(options->repo, pool,
 				  &file_table, i,
 				  rename_src[i].p->one);
 
@@ -354,8 +356,8 @@ static int find_exact_renames(struct diff_options *options)
 	for (i = 0; i < rename_dst_nr; i++)
 		renames += find_identical_files(&file_table, i, options);
 
-	/* Free the hash data structure and entries */
-	hashmap_clear_and_free(&file_table, struct file_similarity, entry);
+	/* Free the hash data structure (entries will be freed with the pool) */
+	hashmap_clear(&file_table);
 
 	return renames;
 }
@@ -1330,7 +1332,47 @@ static void handle_early_known_dir_renames(struct dir_rename_info *info,
 	rename_src_nr = new_num_src;
 }
 
+static void free_filespec_data(struct diff_filespec *spec)
+{
+	if (!--spec->count)
+		diff_free_filespec_data(spec);
+}
+
+static void pool_free_filespec(struct mem_pool *pool,
+			       struct diff_filespec *spec)
+{
+	if (!pool) {
+		free_filespec(spec);
+		return;
+	}
+
+	/*
+	 * Similar to free_filespec(), but only frees the data.  The spec
+	 * itself was allocated in the pool and should not be individually
+	 * freed.
+	 */
+	free_filespec_data(spec);
+}
+
+void pool_diff_free_filepair(struct mem_pool *pool,
+			     struct diff_filepair *p)
+{
+	if (!pool) {
+		diff_free_filepair(p);
+		return;
+	}
+
+	/*
+	 * Similar to diff_free_filepair() but only frees the data from the
+	 * filespecs; not the filespecs or the filepair which were
+	 * allocated from the pool.
+	 */
+	free_filespec_data(p->one);
+	free_filespec_data(p->two);
+}
+
 void diffcore_rename_extended(struct diff_options *options,
+			      struct mem_pool *pool,
 			      struct strintmap *relevant_sources,
 			      struct strintmap *dirs_removed,
 			      struct strmap *dir_rename_count,
@@ -1345,6 +1387,7 @@ void diffcore_rename_extended(struct diff_options *options,
 	int num_destinations, dst_cnt;
 	int num_sources, want_copies;
 	struct progress *progress = NULL;
+	struct mem_pool local_pool;
 	struct dir_rename_info info;
 	struct diff_populate_filespec_options dpf_options = {
 		.check_binary = 0,
@@ -1413,11 +1456,18 @@ void diffcore_rename_extended(struct diff_options *options,
 		goto cleanup; /* nothing to do */
 
 	trace2_region_enter("diff", "exact renames", options->repo);
+	mem_pool_init(&local_pool, 32*1024);
 	/*
 	 * We really want to cull the candidates list early
 	 * with cheap tests in order to avoid doing deltas.
 	 */
-	rename_count = find_exact_renames(options);
+	rename_count = find_exact_renames(options, &local_pool);
+	/*
+	 * Discard local_pool immediately instead of at "cleanup:" in order
+	 * to reduce maximum memory usage; inexact rename detection uses up
+	 * a fair amount of memory, and mem_pools can too.
+	 */
+	mem_pool_discard(&local_pool, 0);
 	trace2_region_leave("diff", "exact renames", options->repo);
 
 	/* Did we only want exact renames? */
@@ -1636,7 +1686,7 @@ void diffcore_rename_extended(struct diff_options *options,
 			pair_to_free = p;
 
 		if (pair_to_free)
-			diff_free_filepair(pair_to_free);
+			pool_diff_free_filepair(pool, pair_to_free);
 	}
 	diff_debug_queue("done copying original", &outq);
 
@@ -1646,7 +1696,7 @@ void diffcore_rename_extended(struct diff_options *options,
 
 	for (i = 0; i < rename_dst_nr; i++)
 		if (rename_dst[i].filespec_to_free)
-			free_filespec(rename_dst[i].filespec_to_free);
+			pool_free_filespec(pool, rename_dst[i].filespec_to_free);
 
 	cleanup_dir_rename_info(&info, dirs_removed, dir_rename_count != NULL);
 	FREE_AND_NULL(rename_dst);
@@ -1663,5 +1713,5 @@ void diffcore_rename_extended(struct diff_options *options,
 
 void diffcore_rename(struct diff_options *options)
 {
-	diffcore_rename_extended(options, NULL, NULL, NULL, NULL);
+	diffcore_rename_extended(options, NULL, NULL, NULL, NULL, NULL);
 }
diff --git a/diffcore.h b/diffcore.h
index 533b30e21e..badc2261c2 100644
--- a/diffcore.h
+++ b/diffcore.h
@@ -127,6 +127,8 @@ struct diff_filepair {
 #define DIFF_PAIR_MODE_CHANGED(p) ((p)->one->mode != (p)->two->mode)
 
 void diff_free_filepair(struct diff_filepair *);
+void pool_diff_free_filepair(struct mem_pool *pool,
+			     struct diff_filepair *p);
 
 int diff_unmodified_pair(struct diff_filepair *);
 
@@ -179,6 +181,7 @@ void partial_clear_dir_rename_count(struct strmap *dir_rename_count);
 void diffcore_break(struct repository *, int);
 void diffcore_rename(struct diff_options *);
 void diffcore_rename_extended(struct diff_options *options,
+			      struct mem_pool *pool,
 			      struct strintmap *relevant_sources,
 			      struct strintmap *dirs_removed,
 			      struct strmap *dir_rename_count,
diff --git a/merge-ort.c b/merge-ort.c
index 6eb910d6f0..515dc39b7f 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -303,8 +303,6 @@ struct merge_options_internal {
 	 *   * these keys serve to intern all the path strings, which allows
 	 *     us to do pointer comparison on directory names instead of
 	 *     strcmp; we just have to be careful to use the interned strings.
-	 *     (Technically paths_to_free may track some strings that were
-	 *      removed from froms paths.)
 	 *
 	 * The values of paths:
 	 *   * either a pointer to a merged_info, or a conflict_info struct
@@ -340,14 +338,14 @@ struct merge_options_internal {
 	struct strmap conflicted;
 
 	/*
-	 * paths_to_free: additional list of strings to free
+	 * pool: memory pool for fast allocation/deallocation
 	 *
-	 * If keys are removed from "paths", they are added to paths_to_free
-	 * to ensure they are later freed.  We avoid free'ing immediately since
-	 * other places (e.g. conflict_info.pathnames[]) may still be
-	 * referencing these paths.
+	 * We allocate room for lots of filenames and auxiliary data
+	 * structures in merge_options_internal, and it tends to all be
+	 * freed together too.  Using a memory pool for these provides a
+	 * nice speedup.
 	 */
-	struct string_list paths_to_free;
+	struct mem_pool pool;
 
 	/*
 	 * output: special messages and conflict notices for various paths
@@ -519,64 +517,45 @@ static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
 {
 	struct rename_info *renames = &opti->renames;
 	int i;
-	void (*strmap_func)(struct strmap *, int) =
+	void (*strmap_clear_func)(struct strmap *, int) =
 		reinitialize ? strmap_partial_clear : strmap_clear;
-	void (*strintmap_func)(struct strintmap *) =
+	void (*strintmap_clear_func)(struct strintmap *) =
 		reinitialize ? strintmap_partial_clear : strintmap_clear;
-	void (*strset_func)(struct strset *) =
+	void (*strset_clear_func)(struct strset *) =
 		reinitialize ? strset_partial_clear : strset_clear;
 
-	/*
-	 * We marked opti->paths with strdup_strings = 0, so that we
-	 * wouldn't have to make another copy of the fullpath created by
-	 * make_traverse_path from setup_path_info().  But, now that we've
-	 * used it and have no other references to these strings, it is time
-	 * to deallocate them.
-	 */
-	free_strmap_strings(&opti->paths);
-	strmap_func(&opti->paths, 1);
+	strmap_clear_func(&opti->paths, 0);
 
 	/*
 	 * All keys and values in opti->conflicted are a subset of those in
 	 * opti->paths.  We don't want to deallocate anything twice, so we
 	 * don't free the keys and we pass 0 for free_values.
 	 */
-	strmap_func(&opti->conflicted, 0);
-
-	/*
-	 * opti->paths_to_free is similar to opti->paths; we created it with
-	 * strdup_strings = 0 to avoid making _another_ copy of the fullpath
-	 * but now that we've used it and have no other references to these
-	 * strings, it is time to deallocate them.  We do so by temporarily
-	 * setting strdup_strings to 1.
-	 */
-	opti->paths_to_free.strdup_strings = 1;
-	string_list_clear(&opti->paths_to_free, 0);
-	opti->paths_to_free.strdup_strings = 0;
+	strmap_clear_func(&opti->conflicted, 0);
 
 	if (opti->attr_index.cache_nr) /* true iff opt->renormalize */
 		discard_index(&opti->attr_index);
 
 	/* Free memory used by various renames maps */
 	for (i = MERGE_SIDE1; i <= MERGE_SIDE2; ++i) {
-		strintmap_func(&renames->dirs_removed[i]);
-		strmap_func(&renames->dir_renames[i], 0);
-		strintmap_func(&renames->relevant_sources[i]);
+		strintmap_clear_func(&renames->dirs_removed[i]);
+		strmap_clear_func(&renames->dir_renames[i], 0);
+		strintmap_clear_func(&renames->relevant_sources[i]);
 		if (!reinitialize)
 			assert(renames->cached_pairs_valid_side == 0);
 		if (i != renames->cached_pairs_valid_side &&
 		    -1 != renames->cached_pairs_valid_side) {
-			strset_func(&renames->cached_target_names[i]);
-			strmap_func(&renames->cached_pairs[i], 1);
-			strset_func(&renames->cached_irrelevant[i]);
+			strset_clear_func(&renames->cached_target_names[i]);
+			strmap_clear_func(&renames->cached_pairs[i], 1);
+			strset_clear_func(&renames->cached_irrelevant[i]);
 			partial_clear_dir_rename_count(&renames->dir_rename_count[i]);
 			if (!reinitialize)
 				strmap_clear(&renames->dir_rename_count[i], 1);
 		}
 	}
 	for (i = MERGE_SIDE1; i <= MERGE_SIDE2; ++i) {
-		strintmap_func(&renames->deferred[i].possible_trivial_merges);
-		strset_func(&renames->deferred[i].target_dirs);
+		strintmap_clear_func(&renames->deferred[i].possible_trivial_merges);
+		strset_clear_func(&renames->deferred[i].target_dirs);
 		renames->deferred[i].trivial_merges_okay = 1; /* 1 == maybe */
 	}
 	renames->cached_pairs_valid_side = 0;
@@ -603,6 +582,8 @@ static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
 		strmap_clear(&opti->output, 0);
 	}
 
+	mem_pool_discard(&opti->pool, 0);
+
 	/* Clean out callback_data as well. */
 	FREE_AND_NULL(renames->callback_data);
 	renames->callback_data_nr = renames->callback_data_alloc = 0;
@@ -665,6 +646,36 @@ static void path_msg(struct merge_options *opt,
 	strbuf_addch(sb, '\n');
 }
 
+static struct diff_filespec *pool_alloc_filespec(struct mem_pool *pool,
+						 const char *path)
+{
+	/* Similar to alloc_filespec(), but allocate from pool and reuse path */
+	struct diff_filespec *spec;
+
+	spec = mem_pool_calloc(pool, 1, sizeof(*spec));
+	spec->path = (char*)path; /* spec won't modify it */
+
+	spec->count = 1;
+	spec->is_binary = -1;
+	return spec;
+}
+
+static struct diff_filepair *pool_diff_queue(struct mem_pool *pool,
+					     struct diff_queue_struct *queue,
+					     struct diff_filespec *one,
+					     struct diff_filespec *two)
+{
+	/* Same code as diff_queue(), except allocate from pool */
+	struct diff_filepair *dp;
+
+	dp = mem_pool_calloc(pool, 1, sizeof(*dp));
+	dp->one = one;
+	dp->two = two;
+	if (queue)
+		diff_q(queue, dp);
+	return dp;
+}
+
 /* add a string to a strbuf, but converting "/" to "_" */
 static void add_flattened_path(struct strbuf *out, const char *s)
 {
@@ -793,8 +804,9 @@ static void setup_path_info(struct merge_options *opt,
 	assert(!df_conflict || !resolved); /* df_conflict implies !resolved */
 	assert(resolved == (merged_version != NULL));
 
-	mi = xcalloc(1, resolved ? sizeof(struct merged_info) :
-				   sizeof(struct conflict_info));
+	mi = mem_pool_calloc(&opt->priv->pool, 1,
+			     resolved ? sizeof(struct merged_info) :
+					sizeof(struct conflict_info));
 	mi->directory_name = current_dir_name;
 	mi->basename_offset = current_dir_name_len;
 	mi->clean = !!resolved;
@@ -891,11 +903,11 @@ static void add_pair(struct merge_options *opt,
 			return;
 	}
 
-	one = alloc_filespec(pathname);
-	two = alloc_filespec(pathname);
+	one = pool_alloc_filespec(&opt->priv->pool, pathname);
+	two = pool_alloc_filespec(&opt->priv->pool, pathname);
 	fill_filespec(is_add ? two : one,
 		      &names[names_idx].oid, 1, names[names_idx].mode);
-	diff_queue(&renames->pairs[side], one, two);
+	pool_diff_queue(&opt->priv->pool, &renames->pairs[side], one, two);
 }
 
 static void collect_rename_info(struct merge_options *opt,
@@ -1086,7 +1098,7 @@ static int collect_merge_info_callback(int n,
 	len = traverse_path_len(info, p->pathlen);
 
 	/* +1 in both of the following lines to include the NUL byte */
-	fullpath = xmalloc(len + 1);
+	fullpath = mem_pool_alloc(&opt->priv->pool, len + 1);
 	make_traverse_path(fullpath, len + 1, info, p->path, p->pathlen);
 
 	/*
@@ -1341,7 +1353,7 @@ static int handle_deferred_entries(struct merge_options *opt,
 		copy = renames->deferred[side].possible_trivial_merges;
 		strintmap_init_with_options(&renames->deferred[side].possible_trivial_merges,
 					    0,
-					    NULL,
+					    &opt->priv->pool,
 					    0);
 		strintmap_for_each_entry(&copy, &iter, entry) {
 			const char *path = entry->key;
@@ -2293,12 +2305,17 @@ static void apply_directory_rename_modifications(struct merge_options *opt,
 	VERIFY_CI(ci);
 
 	/* Find parent directories missing from opt->priv->paths */
-	cur_path = new_path;
+	cur_path = mem_pool_strdup(&opt->priv->pool, new_path);
+	free((char*)new_path);
+	new_path = (char *)cur_path;
+
 	while (1) {
 		/* Find the parent directory of cur_path */
 		char *last_slash = strrchr(cur_path, '/');
 		if (last_slash) {
-			parent_name = xstrndup(cur_path, last_slash - cur_path);
+			parent_name = mem_pool_strndup(&opt->priv->pool,
+						       cur_path,
+						       last_slash - cur_path);
 		} else {
 			parent_name = opt->priv->toplevel_dir;
 			break;
@@ -2307,7 +2324,6 @@ static void apply_directory_rename_modifications(struct merge_options *opt,
 		/* Look it up in opt->priv->paths */
 		entry = strmap_get_entry(&opt->priv->paths, parent_name);
 		if (entry) {
-			free((char*)parent_name);
 			parent_name = entry->key; /* reuse known pointer */
 			break;
 		}
@@ -2334,13 +2350,6 @@ static void apply_directory_rename_modifications(struct merge_options *opt,
 		parent_name = cur_dir;
 	}
 
-	/*
-	 * We are removing old_path from opt->priv->paths.  old_path also will
-	 * eventually need to be freed, but it may still be used by e.g.
-	 * ci->pathnames.  So, store it in another string-list for now.
-	 */
-	string_list_append(&opt->priv->paths_to_free, old_path);
-
 	assert(ci->filemask == 2 || ci->filemask == 4);
 	assert(ci->dirmask == 0);
 	strmap_remove(&opt->priv->paths, old_path, 0);
@@ -2374,7 +2383,6 @@ static void apply_directory_rename_modifications(struct merge_options *opt,
 		new_ci->stages[index].mode = ci->stages[index].mode;
 		oidcpy(&new_ci->stages[index].oid, &ci->stages[index].oid);
 
-		free(ci);
 		ci = new_ci;
 	}
 
@@ -2802,10 +2810,23 @@ static void use_cached_pairs(struct merge_options *opt,
 		if (!new_name)
 			new_name = old_name;
 
+		/*
+		 * cached_pairs has *copies* of old_name and new_name,
+		 * because it has to persist across merges.  Since
+		 * pool_alloc_filespec() will just re-use the existing
+		 * filenames, which will also get re-used by
+		 * opt->priv->paths if they become renames, and then
+		 * get freed at the end of the merge, that would leave
+		 * the copy in cached_pairs dangling.  Avoid this by
+		 * making a copy here.
+		 */
+		old_name = mem_pool_strdup(&opt->priv->pool, old_name);
+		new_name = mem_pool_strdup(&opt->priv->pool, new_name);
+
 		/* We don't care about oid/mode, only filenames and status */
-		one = alloc_filespec(old_name);
-		two = alloc_filespec(new_name);
-		diff_queue(pairs, one, two);
+		one = pool_alloc_filespec(&opt->priv->pool, old_name);
+		two = pool_alloc_filespec(&opt->priv->pool, new_name);
+		pool_diff_queue(&opt->priv->pool, pairs, one, two);
 		pairs->queue[pairs->nr-1]->status = entry->value ? 'R' : 'D';
 	}
 }
@@ -2913,6 +2934,7 @@ static int detect_regular_renames(struct merge_options *opt,
 	diff_queued_diff = renames->pairs[side_index];
 	trace2_region_enter("diff", "diffcore_rename", opt->repo);
 	diffcore_rename_extended(&diff_opts,
+				 &opt->priv->pool,
 				 &renames->relevant_sources[side_index],
 				 &renames->dirs_removed[side_index],
 				 &renames->dir_rename_count[side_index],
@@ -2963,7 +2985,7 @@ static int collect_renames(struct merge_options *opt,
 
 		if (p->status != 'A' && p->status != 'R') {
 			possibly_cache_new_pair(renames, p, side_index, NULL);
-			diff_free_filepair(p);
+			pool_diff_free_filepair(&opt->priv->pool, p);
 			continue;
 		}
 
@@ -2976,7 +2998,7 @@ static int collect_renames(struct merge_options *opt,
 
 		possibly_cache_new_pair(renames, p, side_index, new_path);
 		if (p->status != 'R' && !new_path) {
-			diff_free_filepair(p);
+			pool_diff_free_filepair(&opt->priv->pool, p);
 			continue;
 		}
 
@@ -3094,7 +3116,7 @@ cleanup:
 		side_pairs = &renames->pairs[s];
 		for (i = 0; i < side_pairs->nr; ++i) {
 			struct diff_filepair *p = side_pairs->queue[i];
-			diff_free_filepair(p);
+			pool_diff_free_filepair(&opt->priv->pool, p);
 		}
 	}
 
@@ -3107,7 +3129,8 @@ simple_cleanup:
 	if (combined.nr) {
 		int i;
 		for (i = 0; i < combined.nr; i++)
-			diff_free_filepair(combined.queue[i]);
+			pool_diff_free_filepair(&opt->priv->pool,
+						combined.queue[i]);
 		free(combined.queue);
 	}
 
@@ -3581,7 +3604,8 @@ static void process_entry(struct merge_options *opt,
 		 * the directory to remain here, so we need to move this
 		 * path to some new location.
 		 */
-		CALLOC_ARRAY(new_ci, 1);
+		new_ci = mem_pool_calloc(&opt->priv->pool, 1, sizeof(*new_ci));
+
 		/* We don't really want new_ci->merged.result copied, but it'll
 		 * be overwritten below so it doesn't matter.  We also don't
 		 * want any directory mode/oid values copied, but we'll zero
@@ -3673,7 +3697,8 @@ static void process_entry(struct merge_options *opt,
 			const char *a_path = NULL, *b_path = NULL;
 			int rename_a = 0, rename_b = 0;
 
-			new_ci = xmalloc(sizeof(*new_ci));
+			new_ci = mem_pool_alloc(&opt->priv->pool,
+						sizeof(*new_ci));
 
 			if (S_ISREG(a_mode))
 				rename_a = 1;
@@ -3742,17 +3767,8 @@ static void process_entry(struct merge_options *opt,
 				b_path = path;
 			strmap_put(&opt->priv->paths, b_path, new_ci);
 
-			if (rename_a && rename_b) {
+			if (rename_a && rename_b)
 				strmap_remove(&opt->priv->paths, path, 0);
-				/*
-				 * We removed path from opt->priv->paths.  path
-				 * will also eventually need to be freed, but
-				 * it may still be used by e.g.  ci->pathnames.
-				 * So, store it in another string-list for now.
-				 */
-				string_list_append(&opt->priv->paths_to_free,
-						   path);
-			}
 
 			/*
 			 * Do special handling for b_path since process_entry()
@@ -4293,6 +4309,7 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
 {
 	struct rename_info *renames;
 	int i;
+	struct mem_pool *pool = NULL;
 
 	/* Sanity checks on opt */
 	trace2_region_enter("merge", "sanity checks", opt->repo);
@@ -4358,9 +4375,11 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
 
 	/* Initialization of various renames fields */
 	renames = &opt->priv->renames;
+	mem_pool_init(&opt->priv->pool, 0);
+	pool = &opt->priv->pool;
 	for (i = MERGE_SIDE1; i <= MERGE_SIDE2; i++) {
 		strintmap_init_with_options(&renames->dirs_removed[i],
-					    NOT_RELEVANT, NULL, 0);
+					    NOT_RELEVANT, pool, 0);
 		strmap_init_with_options(&renames->dir_rename_count[i],
 					 NULL, 1);
 		strmap_init_with_options(&renames->dir_renames[i],
@@ -4374,7 +4393,7 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
 		 */
 		strintmap_init_with_options(&renames->relevant_sources[i],
 					    -1 /* explicitly invalid */,
-					    NULL, 0);
+					    pool, 0);
 		strmap_init_with_options(&renames->cached_pairs[i],
 					 NULL, 1);
 		strset_init_with_options(&renames->cached_irrelevant[i],
@@ -4384,9 +4403,9 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
 	}
 	for (i = MERGE_SIDE1; i <= MERGE_SIDE2; i++) {
 		strintmap_init_with_options(&renames->deferred[i].possible_trivial_merges,
-					    0, NULL, 0);
+					    0, pool, 0);
 		strset_init_with_options(&renames->deferred[i].target_dirs,
-					 NULL, 1);
+					 pool, 1);
 		renames->deferred[i].trivial_merges_okay = 1; /* 1 == maybe */
 	}
 
@@ -4394,14 +4413,13 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
 	 * Although we initialize opt->priv->paths with strdup_strings=0,
 	 * that's just to avoid making yet another copy of an allocated
 	 * string.  Putting the entry into paths means we are taking
-	 * ownership, so we will later free it.  paths_to_free is similar.
+	 * ownership, so we will later free it.
 	 *
 	 * In contrast, conflicted just has a subset of keys from paths, so
 	 * we don't want to free those (it'd be a duplicate free).
 	 */
-	strmap_init_with_options(&opt->priv->paths, NULL, 0);
-	strmap_init_with_options(&opt->priv->conflicted, NULL, 0);
-	string_list_init_nodup(&opt->priv->paths_to_free);
+	strmap_init_with_options(&opt->priv->paths, pool, 0);
+	strmap_init_with_options(&opt->priv->conflicted, pool, 0);
 
 	/*
 	 * keys & strbufs in output will sometimes need to outlive "paths",