From 0dde9fd12fd39762ff68fca80d2f0a735d66e7bd Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Tue, 14 Jul 2020 18:02:02 +0200 Subject: [PATCH] qom: Make info qom-tree sort children more efficiently Commit e8c9e65816 "qom: Make "info qom-tree" show children sorted" sorts children the simple, stupid, quadratic way. I thought the number of children would be small enough for this not to matter. I was wrong: there are outliers with several hundred children, e.g ARM machines nuri and smdkc210 each have a node with 513 children. While n^2 sorting isn't noticeable in normal, human usage even for n=513, it can be quite noticeable in certain automated tests. In particular, the sort made device-introspect-test even slower. Commit 3e7b80f84d "tests: improve performance of device-introspect-test" just fixed that by cutting back its excessive use of "info qom-tree". Sorting more efficiently makes sense regardless, so do it. Signed-off-by: Markus Armbruster Message-Id: <20200714160202.3121879-6-armbru@redhat.com> Reviewed-by: Dr. David Alan Gilbert --- qom/qom-hmp-cmds.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/qom/qom-hmp-cmds.c b/qom/qom-hmp-cmds.c index 4032c96089..8861a109d5 100644 --- a/qom/qom-hmp-cmds.c +++ b/qom/qom-hmp-cmds.c @@ -94,25 +94,23 @@ typedef struct QOMCompositionState { static void print_qom_composition(Monitor *mon, Object *obj, int indent); -static int qom_composition_compare(const void *a, const void *b, void *ignore) +static int qom_composition_compare(const void *a, const void *b) { - return g_strcmp0(object_get_canonical_path_component(a), - object_get_canonical_path_component(b)); + return g_strcmp0(object_get_canonical_path_component(*(Object **)a), + object_get_canonical_path_component(*(Object **)b)); } static int insert_qom_composition_child(Object *obj, void *opaque) { - GQueue *children = opaque; - - g_queue_insert_sorted(children, obj, qom_composition_compare, NULL); + g_array_append_val(opaque, obj); return 0; } static void print_qom_composition(Monitor *mon, Object *obj, int indent) { + GArray *children = g_array_new(false, false, sizeof(Object *)); const char *name; - GQueue children; - Object *child; + int i; if (obj == object_get_root()) { name = ""; @@ -122,11 +120,14 @@ static void print_qom_composition(Monitor *mon, Object *obj, int indent) monitor_printf(mon, "%*s/%s (%s)\n", indent, "", name, object_get_typename(obj)); - g_queue_init(&children); - object_child_foreach(obj, insert_qom_composition_child, &children); - while ((child = g_queue_pop_head(&children))) { - print_qom_composition(mon, child, indent + 2); + object_child_foreach(obj, insert_qom_composition_child, children); + g_array_sort(children, qom_composition_compare); + + for (i = 0; i < children->len; i++) { + print_qom_composition(mon, g_array_index(children, Object *, i), + indent + 2); } + g_array_free(children, TRUE); } void hmp_info_qom_tree(Monitor *mon, const QDict *dict)