Re: [PATCH] tools-utils: Do not skip symbolic links when analyzing a linux tree

[Dodji Seketeli <dodji@seketeli.org>]

Hello Matthias,

Matthias Maennich <maennich@google.com> a écrit:

> For various reasons, (parts of) a linux kernel tree containing vmlinux
> and kernel modules might be organized using symbolic links. One reason
> is that those binaries physically reside on a different storage and are
> linked into place. To support such scenarios by allowing to traverse
> symbolic links when discovering linux kernel binaries.
>
> I could not see a reason why this was disabled in the first place.
> Ignoring symbolic links had been the default since the inception of the
> kernel mode.

Following symbolic link is disabled because there can be cases where the
link points to a directory of the kernel tree, causing cycles in the
tree.  In that case, fts_read can return the same file several times.

I seem to remember that it had noticeable performance impacts on the
tests I did with our kernels.

So to support symbolic link, we'd need to properly handle (avoid?) those
cycles, probably by taking into account the FTS_DC bit of the
FTSENT::fts_info data member.  I haven't looked into it in details,
though.

Have you seen the same think in those cases?

Thanks.

[...]

-- 
		Dodji