Re:

2009/5/7 Linus Torvalds [off-list ref]:

Somebody should check. It would be interesting to hear about whether this
makes a performance impact, especially with slow filesystems and/or other
operating systems that have a relatively higher cost for 'lstat()'.

I did (cygwin). My guess, the improvement is completely dwarfed by the
other overheads (like starting git and writing files).

# Without the patch
real    11m22.338s
user    0m54.629s
sys     8m33.638s

# With checkout index preload
real    11m14.361s
user    0m46.609s
sys     7m56.300s

The script:

#!/bin/sh

if [ "$1" = setup ]; then
    for i in 1 2 3 4
    do
        n=$(date)
        for f in `seq 1 10000`
        do
            echo "$n" >file$f
        done
        git add .
        printf "Commit $i:"
        git commit -m"$n"
    done
    exit
fi

export GIT_EXEC_PATH=/d/git-win
time for f in `seq 1 10`
do
    $GIT_EXEC_PATH/git checkout master~3 &&
    $GIT_EXEC_PATH/git checkout master~2 &&
    $GIT_EXEC_PATH/git checkout master~1 &&
    $GIT_EXEC_PATH/git checkout master
done
exit