From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Graf Subject: Re: [PATCH net-next v13 0/3] add hisilicon hip04 ethernet driver Date: Thu, 15 Jan 2015 13:39:03 +0100 Message-ID: <54B7B4E7.8030108@suse.de> References: <1421217254-12008-1-git-send-email-dingtianhong@huawei.com> <54B642B4.8010807@suse.de> <54B77C43.6010200@huawei.com> <14674609.dERhba4yMV@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <14674609.dERhba4yMV@wuerfel> Sender: netdev-owner@vger.kernel.org To: Arnd Bergmann , Ding Tianhong Cc: robh+dt@kernel.org, davem@davemloft.net, grant.likely@linaro.org, sergei.shtylyov@cogentembedded.com, linux-arm-kernel@lists.infradead.org, eric.dumazet@gmail.com, xuwei5@hisilicon.com, zhangfei.gao@linaro.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux@arm.linux.org.uk List-Id: devicetree@vger.kernel.org On 15.01.15 10:42, Arnd Bergmann wrote: > On Thursday 15 January 2015 16:37:23 Ding Tianhong wrote: >> On 2015/1/14 18:19, Alexander Graf wrote: >>> >>> >From a 10000 feet perspective it looks like two problems to me >>> >>> 1) Allocation failure doesn't get handled properly somewhere > > This is the bug that Eric pointed out as well. > >>> 2) We fail to allocate with order=0 - I don't see why > > GFP_ATOMIC. When allocating from a the napi poll function in softirq > context, you have to use nonblocking allocations, which occasionally > fail. This should not cause any harm other than dropped packets. > >> is it easy to repetition this bug? how big is your memory on your board, >> is it happened in your previous hip04 driver? > > It should be independent of memory size, but may be more likely if you > don't have swap space configured. With the previous driver I was unable to get this far - I ended up in random memory corruption and had a ~90% packet loss after about an hour of uptime. I'm not sure whether it's easy to reproduce, I merely started up a few VMs, did some disk I/O and started to compile QEMU in the background ;). I'll happily give your follow up patch that's going to fix the memory allocation problems a try though. Alex