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Diffstat (limited to 'Documentation/technical/racy-git.txt')
| -rw-r--r-- | Documentation/technical/racy-git.txt | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/Documentation/technical/racy-git.txt b/Documentation/technical/racy-git.txt index 5030d9f2f8..53aa0c82c2 100644 --- a/Documentation/technical/racy-git.txt +++ b/Documentation/technical/racy-git.txt @@ -42,10 +42,12 @@ compared, but this is not enabled by default because this member is not stable on network filesystems. With `USE_NSEC` compile-time option, `st_mtim.tv_nsec` and `st_ctim.tv_nsec` members are also compared, but this is not enabled by default -because the value of this member becomes meaningless once the -inode is evicted from the inode cache on filesystems that do not -store it on disk. - +because in-core timestamps can have finer granularity than +on-disk timestamps, resulting in meaningless changes when an +inode is evicted from the inode cache. See commit 8ce13b0 +of git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git +([PATCH] Sync in core time granuality with filesystems, +2005-01-04). Racy git -------- @@ -135,7 +137,7 @@ them, and give the same timestamp to the index file: This will make all index entries racily clean. The linux-2.6 project, for example, there are over 20,000 files in the working -tree. On my Athron 64X2 3800+, after the above: +tree. On my Athlon 64 X2 3800+, after the above: $ /usr/bin/time git diff-files 1.68user 0.54system 0:02.22elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k @@ -184,7 +186,7 @@ In a large project where raciness avoidance cost really matters, however, the initial computation of all object names in the index takes more than one second, and the index file is written out after all that happens. Therefore the timestamp of the -index file will be more than one seconds later than the the +index file will be more than one seconds later than the youngest file in the working tree. This means that in these cases there actually will not be any racily clean entry in the resulting index. |