Hi In a VM, I add a IVSHMEM device, on which the MBUFS mempool resides, and also rings I create (I run a DPDK application in the VM). I saw there is a performance penalty if I use such device, instead of hugepages (the VM's hugepages). My VM's memory is *NOT* backed with host's hugepages. The memory behind the IVSHMEM device is a host hugepage (I use a patched version of QEMU, as provided by Intel). I thought maybe the reason is that this memory is seen by the VM as a mapped PCI memory region, so it is not cached, but I am not sure. So, my direction was to change the kernel (in the VM) so it will consider this memory as a regular memory (and thus cached), instead of a PCI memory region. However, I am not sure my direction is correct, and even if so, I am not sure how/where to change the kernel (my starting point was mm/mmap.c, but I'm not sure it's the correct place to start). Any suggestion is welcomed. Thanks, Eli. ------------------------------------------------------------------------------------------------------------------------------------------------- This email and any files transmitted and/or attachments with it are confidential and proprietary information of Toga Networks Ltd., and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information of Toga Networks Ltd., and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited. ------------------------------------------------------------------------------------------------------------------------------------------------ -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
