From: Linus Torvalds Date: Fri, 10 Aug 2007 16:51:58 +0000 (-0700) Subject: Fix "git commit directory/" performance anomaly X-Git-Tag: v1.5.3-rc5~40 X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=22631473e0b7a33356587ba3e38a9b4cc4dba2f1;p=git.git Fix "git commit directory/" performance anomaly This trivial patch avoids re-hashing files that are already clean in the index. This mirrors what commit 0781b8a9b2fe760fc4ed519a3a26e4b9bd6ccffe did for "git add .", only for "git commit ." instead. This improves the cold-cache case immensely, since we don't need to bring in all the file contents, just the index and any files dirty in the index. Before: [torvalds@woody linux]$ time git commit . real 1m49.537s user 0m3.892s sys 0m2.432s After: [torvalds@woody linux]$ time git commit . real 0m14.273s user 0m1.312s sys 0m0.516s (both after doing a "echo 3 > /proc/sys/vm/drop_caches" to get cold-cache behaviour - even with the index optimization git still has to "lstat()" all the files, so with a truly cold cache, bringing all the inodes in will take some time). [jc: trivial "return 0;" fixed] Signed-off-by: Linus Torvalds Signed-off-by: Junio C Hamano --- diff --git a/builtin-update-index.c b/builtin-update-index.c index 509369e9e..a7a4574f2 100644 --- a/builtin-update-index.c +++ b/builtin-update-index.c @@ -86,9 +86,15 @@ static int process_lstat_error(const char *path, int err) static int add_one_path(struct cache_entry *old, const char *path, int len, struct stat *st) { - int option, size = cache_entry_size(len); - struct cache_entry *ce = xcalloc(1, size); + int option, size; + struct cache_entry *ce; + + /* Was the old index entry already up-to-date? */ + if (old && !ce_stage(old) && !ce_match_stat(old, st, 0)) + return 0; + size = cache_entry_size(len); + ce = xcalloc(1, size); memcpy(ce->name, path, len); ce->ce_flags = htons(len); fill_stat_cache_info(ce, st);