Re: [PATCH 1/2] tools/dma: move dma_map_benchmark from selftests to tools/dma

[Qinxin Xia]

On 2025/8/22 09:12:07, Barry Song <21cnbao@xxxxxxxxx> wrote:
> > Does usr/include have header files? Did you run make headers_install
> > before make?
> > [xiaqinxin@localhost linux]$ make headers_install
> >     HOSTCC  scripts/basic/fixdep
> >     HOSTCC  scripts/unifdef
> >     WRAP    arch/arm64/include/generated/uapi/asm/socket.h
> >     SYSHDR  arch/arm64/include/generated/uapi/asm/unistd_64.h
> >     HDRINST usr/include/asm-generic/mman.h
> >     HDRINST usr/include/asm-generic/stat.h
> >     HDRINST usr/include/asm-generic/ucontext.h
> >     HDRINST usr/include/asm-generic/int-ll64.h
> >     HDRINST usr/include/asm-generic/unistd.h
> >     HDRINST usr/include/asm-generic/kvm_para.h
> >     HDRINST usr/include/asm-generic/types.h
> >     HDRINST usr/include/asm-generic/ipcbuf.h
> >     HDRINST usr/include/asm-generic/termbits-common.h
> > ...
> > [xiaqinxin@localhost linux]$ cd tools/dma/
> > [xiaqinxin@localhost dma]$ make
> > cc -I../../usr/include -I../../include dma_map_benchmark.c -o
> > dma_map_benchmark
>
> This is really frustrating. Why do other parts not need this, but
> dma_map_benchmark does? It is also not acceptable to hardcode the
> path to usr/include.
>
> It is also not good practice to access a kernel header directly from a
> userspace tool - such as -I../../include.
>
> Shouldn't map_benchmark.h be a proper UAPI header that gets installed
> into the toolchain like the others?
Hello Barry :

This include file is inherited from the original version, and there are 
similar

method in other parts ：

pcmcia/Makefile:CFLAGS := -I../../usr/include
laptop/dslm/Makefile:CFLAGS := -I../../usr/include
accounting/Makefile:CFLAGS := -I../../usr/include

During compilation, the system searches for header files from 
../../usr/include first.

If no header file is found in ../../usr/include, the system attempts to 
get header files

from the system directory of the compilation environment. So maybe in 
some compilation

environments, compiling these modules might have the same problem...

'struct map_benchmark' is defined in map_benchmark.h which is used by 
map_benchmark.c

Do we need to define them separately in the kernel and uapi header files?>>
> > My test is ok.
>
>
> Thanks
> Barry