From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54089) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciFpx-0001lC-NJ for qemu-devel@nongnu.org; Mon, 27 Feb 2017 02:35:15 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ciFpt-0000FA-1y for qemu-devel@nongnu.org; Mon, 27 Feb 2017 02:35:13 -0500 Received: from [59.151.112.132] (port=50895 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciFps-0000D8-4l for qemu-devel@nongnu.org; Mon, 27 Feb 2017 02:35:08 -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: Zhang Chen Message-ID: Date: Mon, 27 Feb 2017 15:34:41 +0800 MIME-Version: 1.0 In-Reply-To: <58B3D525.6080104@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit 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: Hailiang Zhang , qemu-devel@nongnu.org Cc: zhangchen.fnst@cn.fujitsu.com, xuquan8@huawei.com 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. 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) >>>> >>> >>> >>> >>> >>> . >>> >> > > > > . > -- Thanks Zhang Chen