Subject: Re: [RFC PATCH 00/11] an introduction of library operating system for Linux (LibOS)

From: Hajime Tazaki <[email-masked]>
Date: Tue, 24 Mar 2015 23:25:28 +0900

Hi,

thanks for your comment.

At Tue, 24 Mar 2015 14:21:49 +0100,
Richard Weinberger wrote:
> 
> Am 24.03.2015 um 14:10 schrieb Hajime Tazaki:
>  > == More information ==
> > 
> > The crucial difference between UML (user-mode linux) and this approach
> > is that we allow multiple network stack instances to co-exist within a
> > single process with dlmopen(3) like linking for easy debugging.
> 
> Is this the only difference?
> We already have arch/um, why do you need arch/lib/ then?
> My point is, can't you merge your arch/lib into the existing arch/um stuff?
> From a very rough look your arch/lib seems like a micro UML.

I understand your point.
but ptrace(2) based system call interception used by UML
makes it depend on the host OS (i.e., linux kernel), while
LibOS uses symbol hijacking with weak alias and LD_PRELOAD.

we're really thinking to run this library on other
POSIX-like hosts (e.g., osx) though it's not coming yet.

> BTW: There was already an idea for having UML as regular library.
> See: http://user-mode-linux.sourceforge.net/old/projects.html
> "UML as a normal userspace library"

thanks, it's new information for me.
were there any trial on this idea ?

-- Hajime