From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39202) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciGtb-0002O6-1z for qemu-devel@nongnu.org; Mon, 27 Feb 2017 03:43:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ciGtX-0006s4-O6 for qemu-devel@nongnu.org; Mon, 27 Feb 2017 03:43:03 -0500 Received: from [45.249.212.187] (port=2993 helo=dggrg01-dlp.huawei.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.71) (envelope-from ) id 1ciGtW-0006qp-QS for qemu-devel@nongnu.org; Mon, 27 Feb 2017 03:42:59 -0500 References: <1487993530-30875-1-git-send-email-zhangchen.fnst@cn.fujitsu.com> <1487993530-30875-4-git-send-email-zhangchen.fnst@cn.fujitsu.com> <58B12B02.2000202@huawei.com> <31f0e89c-13c0-247a-1026-9fc28ee2d6f4@cn.fujitsu.com> <58B3D525.6080104@huawei.com> From: Hailiang Zhang Message-ID: <58B3E69B.2050905@huawei.com> Date: Mon, 27 Feb 2017 16:43:07 +0800 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 2/3] COLO-compare: Optimize colo_packet_compare_common List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Zhang Chen , qemu-devel@nongnu.org Cc: xuquan8@huawei.com On 2017/2/27 15:34, Zhang Chen wrote: > > > On 02/27/2017 03:28 PM, Hailiang Zhang wrote: >> On 2017/2/27 15:03, Zhang Chen wrote: >>> >>> >>> On 02/25/2017 02:58 PM, Hailiang Zhang wrote: >>>> On 2017/2/25 11:32, Zhang Chen wrote: >>>>> Add offset args for colo_packet_compare_common, optimize >>>>> colo_packet_compare_icmp() and colo_packet_compare_udp() >>>>> just compare the IP payload. >>>>> >>>>> Signed-off-by: Zhang Chen >>>>> --- >>>>> net/colo-compare.c | 28 +++++++++++++++++++++------- >>>>> 1 file changed, 21 insertions(+), 7 deletions(-) >>>>> >>>>> diff --git a/net/colo-compare.c b/net/colo-compare.c >>>>> index e75f0ae..9853232 100644 >>>>> --- a/net/colo-compare.c >>>>> +++ b/net/colo-compare.c >>>>> @@ -180,7 +180,7 @@ static int packet_enqueue(CompareState *s, int >>>>> mode) >>>>> * return: 0 means packet same >>>>> * > 0 || < 0 means packet different >>>>> */ >>>>> -static int colo_packet_compare_common(Packet *ppkt, Packet *spkt) >>>>> +static int colo_packet_compare_common(Packet *ppkt, Packet *spkt, >>>>> int offset) >>>>> { >>>>> trace_colo_compare_ip_info(ppkt->size, >>>>> inet_ntoa(ppkt->ip->ip_src), >>>>> inet_ntoa(ppkt->ip->ip_dst), spkt->size, >>>>> @@ -188,7 +188,8 @@ static int colo_packet_compare_common(Packet >>>>> *ppkt, Packet *spkt) >>>>> inet_ntoa(spkt->ip->ip_dst)); >>>>> >>>>> if (ppkt->size == spkt->size) { >>>>> - return memcmp(ppkt->data, spkt->data, spkt->size); >>>>> + return memcmp(ppkt->data + offset, spkt->data + offset, >>>>> + spkt->size - offset); >>>>> } else { >>>>> trace_colo_compare_main("Net packet size are not the >>>>> same"); >>>>> return -1; >>>>> @@ -237,8 +238,7 @@ static int colo_packet_compare_tcp(Packet *spkt, >>>>> Packet *ppkt) >>>>> spkt->ip->ip_sum = ppkt->ip->ip_sum; >>>>> } >>>>> >>>>> - res = memcmp(ppkt->data + ETH_HLEN, spkt->data + ETH_HLEN, >>>>> - (spkt->size - ETH_HLEN)); >>>>> + res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN); >>>>> >>>> >>>> For tcp packets check, why not ignore the ip headers, just like udp >>>> packets check ? >>>> Besides, here, can we compare the checksum stored in headers of tcp >>>> and udp >>>> before call colo_packet_compare_common(), which i think will improve >>>> the comparing >>>> performance. >>> >>> That's another way to compare the packet suggested by Dr. David Alan >>> Gilbert, >>> It makes two packets IP header be same firstly, then compare all IP >>> packet. >>> This way can tell people why we ignore IP header explicitly in other >>> packets check like udp. >>> For performance, If we ignore the IP header that will reduce at least 20 >>> byte not to be compared. >>> So, ignore ip header have better comparing performance. >>> >> >> OK, here, i think we can re-use the checksum value stored in headers >> of tcp >> or udp, comparing it first before comparing the complete payload of >> tcp or udp >> packets is another way to improve the performance, it is only 2 bytes. > > No, The IP header's checksum are always different, Because the IP > header's ID field > are always different. > Not checksum in ip header， i mean checksum in tcp header or udp header. > Thanks > Zhang Chen > >> >> Thanks. >> >>> Thanks >>> Zhang Chen >>> >>> >>>> >>>> Thanks. >>>> Hailiang >>>> >>>>> if (res != 0 && >>>>> trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) { >>>>> trace_colo_compare_pkt_info_src(inet_ntoa(ppkt->ip->ip_src), >>>>> @@ -277,7 +277,14 @@ static int colo_packet_compare_udp(Packet *spkt, >>>>> Packet *ppkt) >>>>> return -1; >>>>> } >>>>> >>>>> - ret = colo_packet_compare_common(ppkt, spkt); >>>>> + /* >>>>> + * Because of ppkt and spkt are both in the same connection, >>>>> + * The ppkt's src ip, dst ip, src port, dst port, ip_proto all >>>>> are >>>>> + * same with spkt. In addition, IP header's Identification is a >>>>> random >>>>> + * field, we can handle it in IP fragmentation function later. >>>>> + * So we just compare the ip payload here. >>>>> + */ >>>>> + ret = colo_packet_compare_common(ppkt, spkt, network_length + >>>>> ETH_HLEN); >>>>> >>>>> if (ret) { >>>>> trace_colo_compare_udp_miscompare("primary pkt size", >>>>> ppkt->size); >>>>> @@ -304,7 +311,14 @@ static int colo_packet_compare_icmp(Packet >>>>> *spkt, Packet *ppkt) >>>>> return -1; >>>>> } >>>>> >>>>> - if (colo_packet_compare_common(ppkt, spkt)) { >>>>> + /* >>>>> + * Because of ppkt and spkt are both in the same connection, >>>>> + * The ppkt's src ip, dst ip, src port, dst port, ip_proto all >>>>> are >>>>> + * same with spkt. In addition, IP header's Identification is a >>>>> random >>>>> + * field, we can handle it in IP fragmentation function later. >>>>> + * So we just compare the ip payload here. >>>>> + */ >>>>> + if (colo_packet_compare_common(ppkt, spkt, network_length + >>>>> ETH_HLEN)) { >>>>> trace_colo_compare_icmp_miscompare("primary pkt size", >>>>> ppkt->size); >>>>> qemu_hexdump((char *)ppkt->data, stderr, "colo-compare", >>>>> @@ -330,7 +344,7 @@ static int colo_packet_compare_other(Packet >>>>> *spkt, Packet *ppkt) >>>>> inet_ntoa(ppkt->ip->ip_dst), spkt->size, >>>>> inet_ntoa(spkt->ip->ip_src), >>>>> inet_ntoa(spkt->ip->ip_dst)); >>>>> - return colo_packet_compare_common(ppkt, spkt); >>>>> + return colo_packet_compare_common(ppkt, spkt, 0); >>>>> } >>>>> >>>>> static int colo_old_packet_check_one(Packet *pkt, int64_t >>>>> *check_time) >>>>> >>>> >>>> >>>> >>>> >>>> . >>>> >>> >> >> >> >> . >> >