Since this timestamp is used to check for racy-clean files, it is important to keep it uptodate.
For the 'git checkout' command without the '-q' option, this make a huge difference. Before, each and every file which was updated, was racy-clean after the call to unpack_trees() and write_index() but before the GIT process ended.
And because of the call to show_local_changes() in builtin-checkout.c, we ended up reading those files back into memory, doing a SHA1 to check if the files was really different from the index. And, of course, no file was different.
With this fix, 'git checkout' without the '-q' option should now be almost as fast as with the '-q' option, but not quite, as we still do some few lstat(2) calls more without the '-q' option.
Below is some average numbers for 10 checkout's to v2.6.27 and 10 to v2.6.25 of the Linux kernel, to show the difference:
before (git version 1.6.2.rc1.256.g58a87): 7.860 user 2.427 sys 19.465 real 52.8% CPU faults: 0 major 95331 minor after: 6.184 user 2.160 sys 17.619 real 47.4% CPU faults: 0 major 38994 minor
Signed-off-by: Kjetil Barvik <barvik@broadpark.no> --- changes since v1:
Have added some lines to the commit log message (se the before and after numbers), one spellfix, and one extra blank line in the patch.
cache.h | 2 +- read-cache.c | 12 ++++++++++-- 2 files changed, 11 insertions(+), 3 deletions(-)
Show changes to 2 files +11 −3
cache.h, read-cache.c
diff --git a/cache.h b/cache.h index 20446c1..7e454a7 100644 --- a/cache.h +++ b/cache.h @@ -430,7 +430,7 @@ extern int read_index_preload(struct index_state *, const char **pathspec); extern int read_index_from(struct index_state *, const char *path); extern int is_index_unborn(struct index_state *); extern int read_index_unmerged(struct index_state *); -extern int write_index(const struct index_state *, int newfd); +extern int write_index(struct index_state *, int newfd); extern int discard_index(struct index_state *); extern int unmerged_index(const struct index_state *); extern int verify_path(const char *path); diff --git a/read-cache.c b/read-cache.c index bb07371..91f1d03 100644 --- a/read-cache.c +++ b/read-cache.c @@ -1528,13 +1528,14 @@ static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce) return ce_write(c, fd, ondisk, size); } -int write_index(const struct index_state *istate, int newfd) +int write_index(struct index_state *istate, int newfd) { git_SHA_CTX c; struct cache_header hdr; int i, err, removed, extended; struct cache_entry **cache = istate->cache; int entries = istate->cache_nr; + struct stat st; for (i = removed = extended = 0; i < entries; i++) { if (cache[i]->ce_flags & CE_REMOVE) @@ -1578,7 +1579,14 @@ int write_index(const struct index_state *istate, int newfd) if (err) return -1; } - return ce_flush(&c, newfd); + + if (ce_flush(&c, newfd) || fstat(newfd, &st)) + return -1; + istate->timestamp.sec = (unsigned int)st.st_ctime; +#ifdef USE_NSEC + istate->timestamp.nsec = (unsigned int)st.st_ctim.tv_nsec; +#endif + return 0; } /*
-- 1.6.1.GIT