From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivan Khoronzhuk Subject: Re: [PATCH] net: core: page_pool: add user refcnt and reintroduce page_pool_destroy Date: Wed, 3 Jul 2019 00:41:43 +0300 Message-ID: <20190702214142.GJ4510@khorivan> References: <156207778364.29180.5111562317930943530.stgit@firesoul> <20190702144426.GD4510@khorivan> <20190702165230.6caa36e3@carbon> <20190702145612.GF4510@khorivan> <20190702171029.76c60538@carbon> <20190702152112.GG4510@khorivan> <20190702202907.15fb30ce@carbon> <20190702185839.GH4510@khorivan> <20190702230241.3be6d787@carbon> <20190702211536.GA22618@apalos> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <20190702211536.GA22618@apalos> Sender: netdev-owner@vger.kernel.org To: Ilias Apalodimas Cc: Jesper Dangaard Brouer , netdev@vger.kernel.org, grygorii.strashko@ti.com, jakub.kicinski@netronome.com, daniel@iogearbox.net, john.fastabend@gmail.com, ast@kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org List-Id: linux-omap@vger.kernel.org On Wed, Jul 03, 2019 at 12:15:36AM +0300, Ilias Apalodimas wrote: >Hi Jesper, >Getting late here, i'll respond in detail tomorrow. One point though > >[...] >> >> This special use-case, seems confined to your driver. And Ilias told me >> that XDP is not really a performance benefit for this driver as the HW >> PPS-limit is hit before the XDP and netstack limit. I ask, does it >> make sense to add XDP to this driver, if it complicates the code for >> everybody else? >I think yes. This is a widely used driver on TI embedded devices so having XDP >to play along is a nice feature. It's also the first and only armv7 we have >supporting this. Ivan already found a couple of issues due to the 32-bit >architecture he is trying to fix, i think there's real benefit in having that, >performance aside. >I fully agree we should not impact the performance of the API to support a >special hardware though. I'll have a look on the 2 solutions tomorrow, but the >general approach on this one should be 'the simpler the better' > >Cheers >/Ilias BTW even w/o optimization it has close to 300kpps (but with increased number of descs) on drop which is very close to netsec measurements Ilias sent. But from what I know there is no h/w limit on cpsw at all that this CPU can serve, so my assumption it's rather s/w limit. But that's not main here and XDP usage has not been estimated enough yet in embedded, where hi speed not only benefit that can be taken from XDP. I need more clear circumstances to send v6 ... -- Regards, Ivan Khoronzhuk