Re: [PATCH] Use a hash rather than a linked-list for cycle check in cp

[Bo Borgerson]

On Tue, Apr 22, 2008 at 3:03 PM, Jim Meyering <address@hidden> wrote:
>
>  Hi Bo,
>
>  Thanks for that patch.
>
>  However, let's see if Cai Xianchao and Li Zefan
>  are still working on rewriting cp to use openat-style functions.
>
>   http://thread.gmane.org/gmane.comp.gnu.coreutils.bugs/12041
>
>  Because once cp is rewritten the way I outlined later in
>  that thread, there will be no need for your patch.
>

Hi,

I may be missing something, but from a scan of that thread it seems to
me that the two patches are actually mutually beneficial.

My patch makes the check for cycles the directory graph cheaper, but
the limitation of PATH_MAX meant that the maximum penalty for this
check wasn't ever that significant.

If the cap on recursion imposed by PATH_MAX were to be lifted then the
performance benefit realized from a cheaper cycle check would be more
significant.

Bo