Paul Eggert <[EMAIL PROTECTED]> wrote: > Jim Meyering <[EMAIL PROTECTED]> writes: > >> CONSECUTIVE_READDIR_UNLINK_THRESHOLD = 200 > > I looked into this a bit, and found myself wondering: why does 'rm' > need to have this constant? Could rm do the rough equivalent of > savedir on the directory (copying its file names and perhaps types > into main memory), and then walk through the in-memory copy of the > directory? > > Such an approach would take more memory, but the extra memory should > be acceptable these days. Also, this approach would walk through the > directory twice, but in the normal case this wouldn't hurt performance > much, and it might even help performance. > > An advantage of this approach is that we wouldn't need these fudge > factors for buggy file systems.
I wrote a prototype savedir-based implementation from scratch. It is a more efficient when there are many directories containing many entries, but it demonstrates O(n^2) performance when the hierarchy is deep and narrow, e.g., /x/x/x/x/x/x/.../x. So, yes, this is worth investigating. _______________________________________________ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
