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[Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance impro
From: |
Pavel Fedin |
Subject: |
[Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement |
Date: |
Tue, 14 Jul 2015 12:39:01 +0300 |
Avoid repetitive lookup of every property in array starting from 0 by adding
one more property which caches last used index. Every time an array is
expanded the index is picked up from this cache.
The property is a uint32_t and its name is name of the array plus '#'
('name#'). It has getter function in order to allow to inspect it from
within monitor.
Another optimization includes avoiding reallocation of 'full_name' every
iteration. Instead, name_no_array buffer is extended and reused.
Signed-off-by: Pavel Fedin <address@hidden>
Reviewed-by: Peter Crosthwaite <address@hidden>
---
qom/object.c | 51 ++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 40 insertions(+), 11 deletions(-)
diff --git a/qom/object.c b/qom/object.c
index ba63777..5820df2 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -10,6 +10,8 @@
* See the COPYING file in the top-level directory.
*/
+#include <glib/gprintf.h>
+
#include "qom/object.h"
#include "qom/object_interfaces.h"
#include "qemu-common.h"
@@ -862,6 +864,14 @@ object_property_add_single(Object *obj, const char *name,
const char *type,
return prop;
}
+static void
+property_get_uint32_opaque(Object *obj, Visitor *v, void *opaque,
+ const char *name, Error **errp)
+{
+ uint32_t value = (uintptr_t)opaque;
+ visit_type_uint32(v, &value, name, errp);
+}
+
ObjectProperty *
object_property_add(Object *obj, const char *name, const char *type,
ObjectPropertyAccessor *get,
@@ -871,27 +881,46 @@ object_property_add(Object *obj, const char *name, const
char *type,
{
size_t name_len = strlen(name);
char *name_no_array;
- ObjectProperty *ret;
- int i;
+ ObjectProperty *ret, *count;
+ uintptr_t i;
if (name_len < 3 || memcmp(&name[name_len - 3], "[*]", 4)) {
return object_property_add_single(obj, name, type,
get, set, release, opaque, errp);
}
- name_no_array = g_strdup(name);
-
- name_no_array[name_len - 3] = '\0';
- for (i = 0; ; ++i) {
- char *full_name = g_strdup_printf("%s[%d]", name_no_array, i);
-
- ret = object_property_add(obj, full_name, type, get, set,
- release, opaque, NULL);
- g_free(full_name);
+ /* 20 characters for maximum possible uintptr_t (64-bit) */
+ name_no_array = g_malloc(name_len + 20);
+ name_len -= 3;
+ memcpy(name_no_array, name, name_len);
+
+ name_no_array[name_len] = '#';
+ name_no_array[name_len + 1] = '\0';
+ count = object_property_find(obj, name_no_array, NULL);
+ if (count == NULL) {
+ /* This is very similar to object_property_add_uint32_ptr(), but:
+ * - Returns pointer
+ * - Will not recurse here, avoiding one condition check
+ * - Allows us to use 'opaque' pointer itself as a storage, because
+ * we want to store only a single integer which should never be
+ * modified from outside.
+ */
+ count = object_property_add_single(obj, name_no_array, "uint32",
+ property_get_uint32_opaque, NULL,
+ NULL, NULL, &error_abort);
+ }
+
+ for (i = (uintptr_t)count->opaque; ; ++i) {
+ g_sprintf(&name_no_array[name_len], "[%zu]", i);
+
+ ret = object_property_add_single(obj, name_no_array, type, get, set,
+ release, opaque, NULL);
if (ret) {
break;
}
}
+
+ count->opaque = (void *)i;
g_free(name_no_array);
return ret;
}
--
1.9.5.msysgit.0
- [Qemu-devel] [PATCH v4 0/2] QOM: object_property_add() performance improvement, Pavel Fedin, 2015/07/14
- [Qemu-devel] [PATCH v4 1/2] QOM: Introduce object_property_add_single(), Pavel Fedin, 2015/07/14
- [Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement,
Pavel Fedin <=
- Re: [Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement, Daniel P. Berrange, 2015/07/27
- Re: [Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement, Markus Armbruster, 2015/07/27
- Re: [Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement, Pavel Fedin, 2015/07/27
- Re: [Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement, Andreas Färber, 2015/07/27
- Re: [Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement, Paolo Bonzini, 2015/07/27
- Re: [Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement, Paolo Bonzini, 2015/07/27
- Re: [Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement, Pavel Fedin, 2015/07/27