From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51051) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZNHaT-0001VP-JA for qemu-devel@nongnu.org; Thu, 06 Aug 2015 05:35:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZNHaQ-00023s-AQ for qemu-devel@nongnu.org; Thu, 06 Aug 2015 05:35:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40578) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZNHaP-00023Z-SO for qemu-devel@nongnu.org; Thu, 06 Aug 2015 05:35:42 -0400 Message-ID: <55C32A65.6060908@redhat.com> Date: Thu, 06 Aug 2015 17:35:33 +0800 From: Jason Wang MIME-Version: 1.0 References: <1438677044-13030-1-git-send-email-yanghy@cn.fujitsu.com> <1438677044-13030-10-git-send-email-yanghy@cn.fujitsu.com> <55C30AE6.8080909@redhat.com> <55C3187C.2050503@cn.fujitsu.com> <55C32448.1030107@redhat.com> <55C327A5.9060802@cn.fujitsu.com> In-Reply-To: <55C327A5.9060802@cn.fujitsu.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 09/11] netfilter: add a netbuffer filter List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yang Hongyang , qemu-devel@nongnu.org Cc: thuth@redhat.com, zhang.zhanghailiang@huawei.com, lizhijian@cn.fujitsu.com, eddie.dong@intel.com, mrhines@linux.vnet.ibm.com, stefanha@redhat.com On 08/06/2015 05:23 PM, Yang Hongyang wrote: > > > On 08/06/2015 05:09 PM, Jason Wang wrote: >> >> >> On 08/06/2015 04:19 PM, Yang Hongyang wrote: >>> >>> >>> On 08/06/2015 03:21 PM, Jason Wang wrote: >>>> >>>> >>>> On 08/04/2015 04:30 PM, Yang Hongyang wrote: >>>>> This filter is to buffer/release packets, this feature can be used >>>>> when using MicroCheckpointing, or other Remus like VM FT >>>>> solutions, you >>>>> can also use it to simulate the network delay. >>>>> It has an interval option, if supplied, this filter will release >>>>> packets by interval. >>>>> >>>>> Usage: >>>>> -netdev tap,id=bn0 >>>>> -netfilter buffer,id=f0,netdev=bn0,chain=in,interval=1000 >>>>> >>>>> NOTE: >>>>> the scale of interval is microsecond. >>>>> >>>>> Signed-off-by: Yang Hongyang >>>>> --- >>>>> v4: remove bh >>>>> pass the packet to next filter instead of receiver >>>>> v3: check packet's sender and sender->peer when flush it >>>>> --- >>>>> [...] >>>>>>> >>>>>>>> + } >>>>>>>> +} >>>>>>>> + >>>>>>>> +static void filter_buffer_release_timer(void *opaque) >>>>>>>> +{ >>>>>>>> + FILTERBUFFERState *s = opaque; >>>>>>>> + filter_buffer_flush(&s->nf); >>>>>>>> + timer_mod(&s->release_timer, >>>>>>>> + qemu_clock_get_us(QEMU_CLOCK_VIRTUAL) + >>>>>>>> s->interval); >>>>>>>> +} >>>>>>>> + >>>>>>>> +/* filter APIs */ >>>>>>>> +static ssize_t filter_buffer_receive_iov(NetFilterState *nf, >>>>>>>> + NetClientState *sender, >>>>>>>> + unsigned flags, >>>>>>>> + const struct iovec *iov, >>>>>>>> + int iovcnt) >>>>>>>> +{ >>>>>>>> + FILTERBUFFERState *s = DO_UPCAST(FILTERBUFFERState, nf, nf); >>>>>>>> + NetQueue *queue = s->incoming_queue; >>>>>>>> + >>>>>>>> + qemu_net_queue_append_iov(queue, sender, flags, iov, iovcnt, >>>>>>>> + packet_send_completed); >>>>>>>> + return iov_size(iov, iovcnt); >>>>>>> >>>>>>> So if interval is zero, packet will be blocked forever and >>>>>>> memory will >>>>>>> be exhausted. >>>>>> >>>>>> Yes, but this supposed to be used by FT solutions, so it will >>>>>> be released periodically. Currently only used with interval makes >>>>>> sense. >>>>>> >>>>> >>>>> Then you need terminate the initialization when interval is zero. > > Ok, but I'd like to also write a comment with it to mention when there're > users, the interval check can be dropped. Ok.