Hi Tariq Thanks for your kindly response. That's really appreciated. On 01/25/2018 05:54 PM, Tariq Toukan wrote: > > > On 25/01/2018 8:25 AM, jianchao.wang wrote: >> Hi Eric >> >> Thanks for you kindly response and suggestion. >> That's really appreciated. >> >> Jianchao >> >> On 01/25/2018 11:55 AM, Eric Dumazet wrote: >>> On Thu, 2018-01-25 at 11:27 +0800, jianchao.wang wrote: >>>> Hi Tariq >>>> >>>> On 01/22/2018 10:12 AM, jianchao.wang wrote: >>>>>>> On 19/01/2018 5:49 PM, Eric Dumazet wrote: >>>>>>>> On Fri, 2018-01-19 at 23:16 +0800, jianchao.wang wrote: >>>>>>>>> Hi Tariq >>>>>>>>> >>>>>>>>> Very sad that the crash was reproduced again after applied the patch. >>>>>> >>>>>> Memory barriers vary for different Archs, can you please share more details regarding arch and repro steps? >>>>> The hardware is HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 12/27/2015 >>>>> The xen is installed. The crash occurred in DOM0. >>>>> Regarding to the repro steps, it is a customer's test which does heavy disk I/O over NFS storage without any guest. >>>>> >>>> >>>> What is the finial suggestion on this ? >>>> If use wmb there, is the performance pulled down ? > > I want to evaluate this effect. > I agree with Eric, expected impact is restricted, especially after batching the allocations.> >>> >>> Since https://urldefense.proofpoint.com/v2/url?u=https-3A__git.kernel.org_pub_scm_linux_kernel_git_davem_net-2Dnext.git_commit_-3Fid-3Ddad42c3038a59d27fced28ee4ec1d4a891b28155&d=DwICaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=7WdAxUBeiTUTCy8v-7zXyr4qk7sx26ATvfo6QSTvZyQ&m=c0oI8duFkyFBILMQYDsqRApHQrOlLY_2uGiz_utcd7s&s=E4_XKmSI0B63qB0DLQ1EX_fj1bOP78ZdeYADBf33B-k&e= >>> >>> we batch allocations, so mlx4_en_refill_rx_buffers() is not called that often. >>> >>> I doubt the additional wmb() will have serious impact there. >>> > > I will test the effect (it'll be beginning of next week). > I'll update so we can make a more confident decision. > I have also sent patches with wmb and batching allocations to customer and let them check whether the performance is impacted. And update here asap when get feedback. > Thanks, > Tariq > >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at https://urldefense.proofpoint.com/v2/url?u=http-3A__vger.kernel.org_majordomo-2Dinfo.html&d=DwICaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=7WdAxUBeiTUTCy8v-7zXyr4qk7sx26ATvfo6QSTvZyQ&m=f0myCdBQoRjaklxGau_S9ZtQKSQYALW9p2MIuTMAEYo&s=447fFu-xZoLvmxdaVhijK6cUk4Jcx7GtBCNddQT4GOQ&e= >> > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
