From f6f78f093b57f2abf82c2ba3d7bf65e533af6ae7 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Sun, 13 Sep 2009 12:11:57 +0200 Subject: doc: NEWS: say quadratic and linear, rather than O(N^2) and O(N) * NEWS: Use a slightly less technical description. Suggested by Andreas Schwab. --- NEWS | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'NEWS') diff --git a/NEWS b/NEWS index ec41ca773..980fb543f 100644 --- a/NEWS +++ b/NEWS @@ -13,12 +13,13 @@ GNU coreutils NEWS -*- outline -*- This makes rm -rf significantly faster (400-500%) in some pathological cases, and slightly slower (20%) in at least one pathological case. - rm -r deletes deep hierarchies more efficiently. Before, it took O(N^2) - time, now it takes O(N), where N is the depth of the hierarchy. However, - this improvement is not as pronounced as might be expected for very - deep trees, because prior to this change, for any relative name length - longer than 8KiB, rm -r would sacrifice official conformance to avoid the - disproportionate O(N^2) performance penalty. Leading to another improvement: + rm -r deletes deep hierarchies more efficiently. Before, execution time + was quadratic in the depth of the hierarchy, now it is merely linear. + However, this improvement is not as pronounced as might be expected for + very deep trees, because prior to this change, for any relative name + length longer than 8KiB, rm -r would sacrifice official conformance to + avoid the disproportionate quadratic performance penalty. Leading to + another improvement: rm -r is now slightly more standards-conformant when operating on write-protected files with relative names longer than 8KiB. -- cgit v1.2.3-54-g00ecf