From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40082) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9ScZ-0002so-BJ for qemu-devel@nongnu.org; Mon, 29 Jun 2015 02:32:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z9ScW-0003mE-28 for qemu-devel@nongnu.org; Mon, 29 Jun 2015 02:32:47 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:33357) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9ScV-0003li-Pp for qemu-devel@nongnu.org; Mon, 29 Jun 2015 02:32:43 -0400 Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout2.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NQP00MA50UFGF50@mailout2.w1.samsung.com> for qemu-devel@nongnu.org; Mon, 29 Jun 2015 07:32:39 +0100 (BST) From: Pavel Fedin References: <017b01d0a809$0f682580$2e387080$@samsung.com> In-reply-to: Date: Mon, 29 Jun 2015 09:32:38 +0300 Message-id: <03ea01d0b235$64d42560$2e7c7020$@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=UTF-8 Content-transfer-encoding: quoted-printable Content-language: ru Subject: Re: [Qemu-devel] [PATCH v3] QOM: object_property_add() performance improvement List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?UTF-8?Q?'Andreas_F=C3=A4rber'?= Cc: 'Peter Crosthwaite' , 'QEMU Developers' I am here, was checking submission statuses and was going to PING = too... Andreas???! Kind regards, Pavel Fedin Expert Engineer Samsung Electronics Research center Russia > -----Original Message----- > From: qemu-devel-bounces+p.fedin=3Dsamsung.com@nongnu.org = [mailto:qemu-devel- > bounces+p.fedin=3Dsamsung.com@nongnu.org] On Behalf Of Peter = Crosthwaite > Sent: Saturday, June 27, 2015 6:28 AM > To: Pavel Fedin > Cc: QEMU Developers; Andreas F=C3=A4rber > Subject: Re: [Qemu-devel] [PATCH v3] QOM: object_property_add() = performance improvement >=20 > Ping! >=20 > Regards, > Peter >=20 > On Tue, Jun 16, 2015 at 12:50 AM, Pavel Fedin = wrote: > > The function originally behaves very badly when adding properties = with "[*]" > > suffix. Normally these are used for numbering IRQ pins. In order to = find the > > correct starting number the function started from zero and checked = for > > duplicates. This takes incredibly long time with large number of = CPUs because > > number of IRQ pins on some architectures (like ARM GICv3) gets = multiplied by > > number of CPUs. > > > > The solution is to add one more property which caches last used = index so that > > duplication check is not repeated thousands of times. Every time an = array is > > expanded the index is picked up from this cache. > > The property is a uint32_t and has the original name of the array = ('name[*]') > > for simplicity. It has getter function in order to allow to inspect = it from > > within monitor. > > > > The modification decreases qemu startup time with 32 CPUs by a = factor of 2 > > (~10 sec vs ~20 sec). > > > > Signed-off-by: Pavel Fedin > > Reviewed-by: Peter Crosthwaite > > --- > > Changes since v2: > > - Fixed line spacing > > - 'i' is now uintptr_t, got rid of double-casting from void *. = String space is enlarged to > > 20 characters in order to accommodate maximum possible 64-bit value. > > --- > > qom/object.c | 93 = ++++++++++++++++++++++++++++++++++++++++++------------------ > > 1 file changed, 66 insertions(+), 27 deletions(-) > > > > diff --git a/qom/object.c b/qom/object.c > > index 96abd34..e8b94fb 100644 > > --- a/qom/object.c > > +++ b/qom/object.c > > @@ -10,6 +10,8 @@ > > * See the COPYING file in the top-level directory. > > */ > > > > +#include > > + > > #include "qom/object.h" > > #include "qemu-common.h" > > #include "qapi/visitor.h" > > @@ -721,35 +723,14 @@ void object_unref(Object *obj) > > } > > } > > > > -ObjectProperty * > > -object_property_add(Object *obj, const char *name, const char = *type, > > - ObjectPropertyAccessor *get, > > - ObjectPropertyAccessor *set, > > - ObjectPropertyRelease *release, > > - void *opaque, Error **errp) > > +static ObjectProperty * > > +object_property_add_single(Object *obj, const char *name, const = char *type, > > + ObjectPropertyAccessor *get, > > + ObjectPropertyAccessor *set, > > + ObjectPropertyRelease *release, > > + void *opaque, Error **errp) > > { > > ObjectProperty *prop; > > - size_t name_len =3D strlen(name); > > - > > - if (name_len >=3D 3 && !memcmp(name + name_len - 3, "[*]", 4)) = { > > - int i; > > - ObjectProperty *ret; > > - char *name_no_array =3D g_strdup(name); > > - > > - name_no_array[name_len - 3] =3D '\0'; > > - for (i =3D 0; ; ++i) { > > - char *full_name =3D g_strdup_printf("%s[%d]", = name_no_array, i); > > - > > - ret =3D object_property_add(obj, full_name, type, get, = set, > > - release, opaque, NULL); > > - g_free(full_name); > > - if (ret) { > > - break; > > - } > > - } > > - g_free(name_no_array); > > - return ret; > > - } > > > > QTAILQ_FOREACH(prop, &obj->properties, node) { > > if (strcmp(prop->name, name) =3D=3D 0) { > > @@ -774,6 +755,64 @@ object_property_add(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 =3D (uintptr_t)opaque; > > + visit_type_uint32(v, &value, name, errp); > > +} > > + > > +ObjectProperty * > > +object_property_add(Object *obj, const char *name, const char = *type, > > + ObjectPropertyAccessor *get, > > + ObjectPropertyAccessor *set, > > + ObjectPropertyRelease *release, > > + void *opaque, Error **errp) > > +{ > > + size_t name_len =3D strlen(name); > > + char *name_no_array; > > + 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); > > + } > > + > > + /* 20 characters for maximum possible uintptr_t (64-bit) */ > > + name_no_array =3D g_malloc(name_len + 20); > > + > > + count =3D object_property_find(obj, name, NULL); > > + if (count =3D=3D NULL) { > > + /* This is very similar to = object_property_add_uint32_ptr(), but: > > + * - Returns pointer > > + * - Will not recurse here so that we can use raw name with = [*] > > + * - Allows us to use 'opaque' pointer itself as a storage, = because > > + * we want to store only a single integer which should = not be > > + * modified from outside. > > + */ > > + count =3D object_property_add_single(obj, name, "uint32", > > + = property_get_uint32_opaque, NULL, > > + NULL, NULL, = &error_abort); > > + } > > + > > + name_len -=3D 3; > > + memcpy(name_no_array, name, name_len); > > + i =3D (uintptr_t)count->opaque; > > + > > + do { > > + g_sprintf(&name_no_array[name_len], "[%zu]", i++); > > + > > + ret =3D object_property_add_single(obj, name_no_array, = type, get, set, > > + release, opaque, NULL); > > + } while (!ret); > > + > > + count->opaque =3D (void *)i; > > + g_free(name_no_array); > > + return ret; > > +} > > + > > ObjectProperty *object_property_find(Object *obj, const char *name, > > Error **errp) > > { > > -- > > 1.9.5.msysgit.0 > > > > > >