Re: [PATCH v2] Huge performance boost for recursion (cp, du, find, ls, rm, mv)

On Wed, 1 Apr 2026 at 20:20, Jody Bruchon via busybox
<[email protected]> wrote:
>
> On 2025-08-04 1:22 PM, Denys Vlasenko wrote:
> > On Tue, Apr 16, 2024 at 4:10 AM Jody Bruchon <[email protected]> wrote:

[...]

> > +    buf = (char *)malloc(end_offset + 1);
> > +    if (!buf) return NULL;
> >
> > Use xmalloc.
>
> Fair. Sorry.
>
> > +    if (dirp->d_name && DOT_OR_DOTDOT(dirp->d_name))
> > +        return NULL;
> >
> > dirp->d_name is never NULL, don't check for that.
>
> True. I can remove that part. I tend to code defensively, but I see that
> check's lack of value here.

Defensive coding about p != NULL is a good practice that shouldn't be
avoided unless a branch-analyzer is used as an automatism to grant p
!= NULL at every code change.

https://github.com/robang74/busybox/commits/features/

In the meantime, I rewrote the features branch repairing tabs from
spaces and added this Jody's patch with two variations: xmalloc (ok)
and cleanup comments //previous function.

#ifndef USE_FAST_SUBPATH
newfile = concat_subpath_file(filename, entry->d_name);
#else
newfile = concat_subpath_file_fast(filename, entry);
#endif

The above approach will help confrontation and further tests on
different platforms. Cache optimisations are great usually, but their
results are varying among platforms.

Best regards, R-
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