From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55003) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d06wE-0002ol-Ks for qemu-devel@nongnu.org; Mon, 17 Apr 2017 09:43:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d06wB-0001Rn-HZ for qemu-devel@nongnu.org; Mon, 17 Apr 2017 09:43:30 -0400 Received: from mail-qt0-x241.google.com ([2607:f8b0:400d:c0d::241]:32994) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1d06wB-0001Rc-Cu for qemu-devel@nongnu.org; Mon, 17 Apr 2017 09:43:27 -0400 Received: by mail-qt0-x241.google.com with SMTP id c45so18634798qtb.0 for ; Mon, 17 Apr 2017 06:43:27 -0700 (PDT) Sender: =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= References: <1492334677-14170-1-git-send-email-zhangchen.fnst@cn.fujitsu.com> <1492334677-14170-2-git-send-email-zhangchen.fnst@cn.fujitsu.com> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Message-ID: <3a4f5675-bcea-96f5-5dd2-a3d4355cbe7a@amsat.org> Date: Mon, 17 Apr 2017 10:43:22 -0300 MIME-Version: 1.0 In-Reply-To: <1492334677-14170-2-git-send-email-zhangchen.fnst@cn.fujitsu.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/2] COLO-compare: Optimize tcp compare for option field List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Zhang Chen , qemu devel , Jason Wang Cc: Li Zhijian , bian naimeng , "eddie . dong" , zhanghailiang Hi Zhang, On 04/16/2017 06:24 AM, Zhang Chen wrote: > In this patch we support packet that have tcp options field. > Add tcp options field check, If the packet have options > field we just skip it and compare tcp payload, > Avoid unnecessary checkpoint, optimize performance. > > Signed-off-by: Zhang Chen > --- > net/colo-compare.c | 27 ++++++++++++++++++++++++++- > 1 file changed, 26 insertions(+), 1 deletion(-) > > diff --git a/net/colo-compare.c b/net/colo-compare.c > index aada04e..881d6b2 100644 > --- a/net/colo-compare.c > +++ b/net/colo-compare.c > @@ -228,6 +228,7 @@ static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt) > { > struct tcphdr *ptcp, *stcp; > int res; > + int tcp_offset = 0; No need to declare here, it can be restricted to the if {} body. > > trace_colo_compare_main("compare tcp"); > > @@ -248,7 +249,31 @@ static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt) > spkt->ip->ip_sum = ppkt->ip->ip_sum; > } > > - if (ptcp->th_sum == stcp->th_sum) { > + /* > + * Check tcp header length for tcp option field. > + * th_off > 5 means this tcp packet have options field. > + * The tcp options maybe always different. > + * for example: > + * From RFC 7323. > + * TCP Timestamps option (TSopt): > + * Kind: 8 > + * > + * Length: 10 bytes > + * > + * +-------+-------+---------------------+---------------------+ > + * |Kind=8 | 10 | TS Value (TSval) |TS Echo Reply (TSecr)| > + * +-------+-------+---------------------+---------------------+ > + * 1 1 4 4 > + * > + * In this case the primary guest's timestamp always different with > + * the secondary guest's timestamp. COLO just focus on payload, > + * so we just need skip this field. > + */ > + if (ptcp->th_off > 5) { You can declare here. I'd rather declare tcp_offset as a ptrdiff_t. > + tcp_offset = ppkt->transport_header - (uint8_t *)ppkt->data > + + (ptcp->th_off * 4); > + res = colo_packet_compare_common(ppkt, spkt, tcp_offset); > + } else if (ptcp->th_sum == stcp->th_sum) { > res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN); > } else { > res = -1; >