Re: [bug report] iommu_dma_unmap_sg() is very slow then running IO from remote numa node

From: Ming Lei
Date: Tue Jul 20 2021 - 21:41:28 EST

On Mon, Jul 19, 2021 at 05:14:28PM +0100, John Garry wrote:
> On 09/07/2021 15:24, Ming Lei wrote:
> > > associated compromises.
> > Follows the log of 'perf report'
> >
> > 1) good(run fio from cpus in the nvme's numa node)
> Hi Ming,
> If you're still interested in this issue, as an experiment only you can try
> my rebased patches here:
> I think that you should see a significant performance boost.

There is build issue, please check your tree:

MODPOST vmlinux.symvers
MODINFO modules.builtin.modinfo
GEN modules.builtin
LD .tmp_vmlinux.btf
ld: Unexpected GOT/PLT entries detected!
ld: Unexpected run-time procedure linkages detected!
ld: drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.o: in function `smmu_test_store':
/root/git/linux/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c:3892: undefined reference to `smmu_test_core'
BTF .btf.vmlinux.bin.o
pahole: .tmp_vmlinux.btf: No such file or directory
LD .tmp_vmlinux.kallsyms1
.btf.vmlinux.bin.o: file not recognized: file format not recognized
make: *** [Makefile:1177: vmlinux] Error 1