Date: Fri, 13 Sep 2013 12:37:29 -0700 From: Adrian Chadd <adrian@freebsd.org> To: Chenchong Qin <qinchenchong@gmail.com> Cc: "freebsd-wireless@freebsd.org" <freebsd-wireless@freebsd.org> Subject: Re: Chenchong's work on net80211_ratectl Message-ID: <CAJ-Vmo=Se2JziV8D2PYNgxmZro-3JRpp3ZsRkTTWvUQ0YigRPw@mail.gmail.com> In-Reply-To: <CAFnsE3dxXr05%2Bv7F2hF7Qauoz-qqDzxkXiZrhUAtaxf0ObNhDg@mail.gmail.com> References: <CAFnsE3dYdPf5yGTFH683Q1Zh0mc-g%2B_YtCTraNNt28z2vBoSKw@mail.gmail.com> <CAJ-Vmom4sY7jcNwWmJkrDwfWjsok2fk8UEwTi5A=egj1JyerLw@mail.gmail.com> <CAFnsE3cyg=msBfQqqKUMmLABSL=j24VoMBwbBjxQ6b7Dyy7Mqg@mail.gmail.com> <CAJ-Vmo=k8NddAYyAJCkx4eOaA_8XsSxg6uKrdddx%2BgmeT%2BX9KA@mail.gmail.com> <CAFnsE3eaOyRcO3LXSi3L=jbzpyMv5Nt_jRGKt_mmA0WV-EV5vA@mail.gmail.com> <CAJ-VmokdxLhK5x6kO=jJzk-dv61EDK-ZgmndOimoyWWf76HiZA@mail.gmail.com> <CAJ-VmonMjR5iVTMVN9532d%2BPqOXWNUoZvxPtQir5h=yGxU-XdQ@mail.gmail.com> <CAFnsE3d9nG-X2b=z1srKfTtpxC3w5L%2B6Hg3TbOnAQrJN%2Bt19GA@mail.gmail.com> <CAJ-VmokF6hPtg9FoEdeJXLLaZRNhzd=nr_o6nHE%2BjYiQKTg3zQ@mail.gmail.com> <CAFnsE3eMwX-GiRzJt8jk4r9mxwSAQkcrDwk%2BnWVG7q6dabeA3A@mail.gmail.com> <CAJ-Vmo=mzvS0UBC7fGx2t501%2Bfioi4DJcw8qobOpbYOUiraqGg@mail.gmail.com> <CAFnsE3df=1WEuLZh5355v_K2eBgcuBbpoza74Y-5vvNupBz22A@mail.gmail.com> <CAJ-VmokyXwkKLdsJw74bux7G5EJSRvFhugTcLR9BgXfw4ysYRg@mail.gmail.com> <CAJ-VmokU=ZXysjZfAJ-REZL7kwg-_Z-LeAKca7AefONW_O1E5A@mail.gmail.com> <CAFnsE3cS_2Ad1geQQ0UB4doEgqVfhNBMi6j4fCRpFgQqcu2kJw@mail.gmail.com> <CAFnsE3eMrwpo=hcFb9XfpLL53Ppso%2B%2BXTBfpieP8FGejAKW1_w@mail.gmail.com> <CAJ-Vmo=s=0u7VO00vgzxmR7bE4aTtMrshZ3j5F312dya284V1g@mail.gmail.com> <CAFnsE3c%2BOg_2hVXO3zU7gmY4xFQjnxbv=ehJm=pbbpLJcgwJrQ@mail.gmail.com> <CAJ-Vmo=D3BNhhSn9D3x6hBry=fDecOd7BwttQ5Yw2iUKGDBN3w@mail.gmail.com> <CAFnsE3dw5bOyVRqMb9K3ME%2BHoDL61-e_XNJjjt_nRTaY=4dnhw@mail.gmail.com> <CAJ-Vmo=0tkTKQnOjrmYKqWqC%2B_nnFLqimdp06STETxLsFgxKxQ@mail.gmail.com> <CAFnsE3dm27483GVp4PRiwk=sxagT7NXQz4fmyOpth2zpCM2MwQ@mail.gmail.com> <CAFnsE3fvpjCXEC1gN46VXfPdeXG5RSVzNiJkZJiQ6xSYQFb89g@mail.gmail.com> <CAFnsE3e1r6Ah5SSrqnrxoqXMRm3yCaUxCjSD90epWQJEZU-pzw@mail.gmail.com> <CAJ-Vmok3dAHiwbeyEU6B4oWm=n36ME2yyGE69twjdEygr8iZSw@mail.gmail.com> <CAFnsE3dxXr05%2Bv7F2hF7Qauoz-qqDzxkXiZrhUAtaxf0ObNhDg@mail.gmail.com>
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Sweet, thanks! -adrian On 13 September 2013 09:11, Chenchong Qin <qinchenchong@gmail.com> wrote: > Hi! > > Here is some updates. > > Another member is added to ieee80211_rc_info to record value of the > maximum aggregate size. Then, in aggregation scenario, ratectl algo can > inform aggregation selection code of proper maximum aggregate size. > > Per-vap ratectl statistics is exported through sysctl. When > ieee80211_ratectl_init() is called, this statistics api is attached. It's > convenient to implement the per-device api -- just traverse the vap list > and call per-vap api for each vap. But, we know that ratectl of net80211 > provides service to vap-granularity object, not to device directly. So, is > it more suitable to implement the per-device api in device driver (i.e. > attach per-device api when attaching the device)? > > Code will be posted later. > > Thanks! > > Chenchong > > > On Thu, Sep 12, 2013 at 2:05 AM, Adrian Chadd <adrian@freebsd.org> wrote: > >> Hi, >> >> For now, yes, you have to assume that you won't always get a response for >> a rate lookup. The buffer may be sent with NOACK set, it may be deleted >> during a channel change or scan, etc. >> >> And yes - the rate control lookup stuff for aggregate frames is a bit >> messy. It would be nice for the rate control code to return the rate _and_ >> the maximum aggregate size, in case the aggregation selection wants to cap >> how long frames are at the given choice. >> >> >> >> -adrian >> >> >> >> On 11 September 2013 10:29, Chenchong Qin <qinchenchong@gmail.com> wrote: >> >>> Hi! >>> >>> I've added some aggregation support here! >>> >>> At first I intend to pass subframe informations(nframes, per-subframe >>> length etc.) >>> to the ratectl api. But it seems to be a paradox that rate lookup must >>> be performed >>> before the ampdu is formed (aggregation limit based on the rate control >>> decision >>> is need) and subframe informations can be obtain only after the ampdu is >>> formed. >>> So, I add a new ieee80211_rc_info flag to ieee80211_ratectl to let it >>> distinguish >>> aggregation and non-aggregation scenarios. If rate lookup is called in >>> an aggregation >>> scenario, this flag is set. Then, ratectl algo knows that it's now >>> finding rates for an >>> ampdu and the framelen which records len of the first frame can be >>> ignored. When >>> it comes to complete period, tx status that shows number of subframes >>> been sent >>> and number of subframes been successfully received is passed to the >>> ratectl api. >>> >>> I also get a question here - whether one tx that doesn't perform rate >>> lookup will call >>> the complete procedure? >>> >>> Thanks! >>> >>> Chenchong >>> >>> >>> On Sun, Sep 8, 2013 at 11:18 PM, Chenchong Qin <qinchenchong@gmail.com>wrote: >>> >>>> Hi! >>>> >>>> I've added the common ratectl state as an mbuf tag! >>>> >>>> After days of frustration (compile errors, boot failed, kernel panics, >>>> suddenly kernel freezing...), it seems that ath now can use 11n-aware >>>> net80211 ratectl api to do rate control. Attachment[0] is the diff of >>>> modifications to dev/ath. Changes to net80211 is minor this time. Just add >>>> some debug msgs to it. Please reference my gsoc svn repo<https://svnweb.freebsd.org/socsvn/soc2013/ccqin/head/>; >>>> . >>>> >>>> It's worth mentioning that sometimes the kernel will "freezing" (it >>>> looks like all things stop working, screen is freezing, keyboard and mouse >>>> are not responding) after wireless stuff start working for a while. At >>>> first, I consider it caused by my modification to ath. But this strange >>>> thing can also happen in a head kernel (r255382). Attachment[1] is some >>>> useful messages just before it happens. By the way, I use a AR9227 device. >>>> >>>> And, I found that, for aggregation scenario, ath gathers tx information >>>> and update the ratectl states. So, what we can do to net80211 to let it >>>> support aggregation? >>>> >>>> Thanks! >>>> >>>> Chenchong >>>> >>>> >>>> On Tue, Sep 3, 2013 at 9:29 AM, Chenchong Qin <qinchenchong@gmail.com>wrote: >>>> >>>>> OK! >>>>> >>>>> Thanks! :-) >>>>> >>>>> Chenchong >>>>> >>>>> >>>>> On Tue, Sep 3, 2013 at 1:56 AM, Adrian Chadd <adrian@freebsd.org>wrote: >>>>> >>>>>> Hi! >>>>>> >>>>>> You can declare an mbuf tag and use that. Look at M_TXCB in net80211 >>>>>> and how mbuf tags are added. >>>>>> >>>>>> I've long thought about adding a net80211 mbuf tag to represent -all- >>>>>> of the tx related state - TX callback, rate control, rate completion, >>>>>> aggregation state, retry count, etc. That way all the drivers can use it. >>>>>> >>>>>> >>>>>> >>>>>> -adrian >>>>>> >>>>>> >>>>> >>>> >>> >> >
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