On 3/27/2018 5:54 PM, Alexander Duyck wrote: > I view the wmb() + writel_relaxed() as more of a driver owning and > handling this itself. Besides in the Intel Ethernet driver case it is > better performance as our wmb() placement for us also provides a > secondary barrier so we don't need to add a separate smp_wmb() to deal > with a potential race we have with the Tx cleanup. Thanks for the reminder. I forgot about the double barrier optimization. wmb() + writel_relaxed() seems to be the best option for Intel network drivers at this moment. Otherwise, we'll have to remove wmb() and throw in smp barriers there like you mentioned. I'll leave the changes in the Intel drivers alone. -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. -- 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
