On Wed, May 15, 2019 at 08:31:49AM +0200, Arnd Bergmann wrote: > On Wed, May 15, 2019 at 7:04 AM Leon Romanovsky <leonro@xxxxxxxxxxxx> wrote: > > On Tue, May 14, 2019 at 09:32:02PM -0300, Jason Gunthorpe wrote: > > > On Tue, May 14, 2019 at 12:45:10PM -0700, Nathan Chancellor wrote: > > > > Hi all, > > > > > > > > I checked the RDMA mailing list and trees and I haven't seen this > > > > reported/fixed yet (forgive me if it has) but when building for arm32 > > > > with multi_v7_defconfig and the following configs (distilled from > > > > allyesconfig): > > > > > > > > CONFIG_INFINIBAND=y > > > > CONFIG_INFINIBAND_ON_DEMAND_PAGING=y > > > > CONFIG_INFINIBAND_USER_ACCESS=y > > > > CONFIG_MLX5_CORE=y > > > > CONFIG_MLX5_INFINIBAND=y > > > > > > > > The following link time errors occur: > > > > > > > > arm-linux-gnueabi-ld: drivers/infiniband/hw/mlx5/main.o: in function `mlx5_ib_alloc_dm': > > > > main.c:(.text+0x60c): undefined reference to `__aeabi_uldivmod' > > > > arm-linux-gnueabi-ld: drivers/infiniband/hw/mlx5/cmd.o: in function `mlx5_cmd_alloc_sw_icm': > > > > cmd.c:(.text+0x6d4): undefined reference to `__aeabi_uldivmod' > > > > arm-linux-gnueabi-ld: drivers/infiniband/hw/mlx5/cmd.o: in function `mlx5_cmd_dealloc_sw_icm': > > > > cmd.c:(.text+0x9ec): undefined reference to `__aeabi_uldivmod' > > > > > > Fengguang, I'm surprised that 0-day didn't report this earlier.. > > > > I got many successful emails after I pushed this patch to 0-day testing. > > The long division warnings can compiler specific, and depend on certain > optimization options, as compilers can optimize out certain divisions and > replace them with multiplications and/or shifts, or prove that they can be > replaced with a 32-bit division. If this is a case that gcc manages to > optimize but clang does not, it might be worth looking into whether an > optimization can be added to clang, in addition to improving the source. > > Arnd While I did run initially run into this with clang, the errors above are with gcc (mainly to show this was going to be a universal problem and not just something with clang). Nathan
