Re: [RFC PATCH 00/35] remove in-kernel syscall invocations

From: Ingo Molnar
Date: Mon Mar 12 2018 - 03:33:03 EST



* Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> wrote:

> I'm a bit more unsure about these remaining patches. They use inline stubs
> named ksys_xyzzy() which (mostly) call fs-internal functions. Another
> alternative would be to define these in fs/*, but then we'd get more and
> more indirections.
>
> syscalls: do not call sys_unlink() within the kernel
> syscalls: do not call sys_rmdir() within the kernel
> syscalls: do not call sys_mkdir{,at}() within the kernel
> syscalls: do not call sys_symlink{,at}() within the kernel
> syscalls: do not call sys_mknod{,at}() within the kernel
> syscalls: do not call sys_link{,at}() within the kernel
> syscalls: do not call sys_{f,}chmod{at,}() within the kernel
> syscalls: do not call sys_{f,}access{,at}() within the kernel
> syscalls: do not call sys_ftruncate() within the kernel
> syscalls: do not call sys_{,l,f}chown() within the kernel
> syscalls: do not call sys_close() within the kernel

> 72 files changed, 572 insertions(+), 274 deletions(-)

Just curious, have you done a before/after vmlinux /usr/bin/size comparison?
How do these changes impact generated code?

My expectation would be for there to be a noticeable decrease in text size.

Thanks,

Ingo