From 94a9116175d902b803fa2f29b5454acee26e57b4 Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Wed, 22 Sep 2021 16:28:06 -0400 Subject: [PATCH] comment --- ..._85f07d906b836ac968ab877258180c0c._comment | 33 +++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 doc/bugs/Windows__58___substantial_per-file_cost_for___96__add__96__/comment_3_85f07d906b836ac968ab877258180c0c._comment diff --git a/doc/bugs/Windows__58___substantial_per-file_cost_for___96__add__96__/comment_3_85f07d906b836ac968ab877258180c0c._comment b/doc/bugs/Windows__58___substantial_per-file_cost_for___96__add__96__/comment_3_85f07d906b836ac968ab877258180c0c._comment new file mode 100644 index 0000000000..ce7bb40133 --- /dev/null +++ b/doc/bugs/Windows__58___substantial_per-file_cost_for___96__add__96__/comment_3_85f07d906b836ac968ab877258180c0c._comment @@ -0,0 +1,33 @@ +[[!comment format=mdwn + username="joey" + subject="""comment 3""" + date="2021-09-22T19:33:58Z" + content=""" +Look at the 3 git add results, dividing windows runtime by linux: + + 1.9/0.05 = 38.00 + 4.5/0.08 = 56.25 + 13.1/0.36 = 36.39 + +The middle is slightly an outlier, and it would be better to have more data +points, but what this says to me is it's probably around 38x more expensive +on windows than on linux for git-annex smudge --clean to run. + +git-annex smudge --clean makes on the order of 3000 syscalls, including +opening 200 files, execing git 30 times, and statting 400 files. That's +around 10x as many syscalls as git add makes. And it's run once per file. So +relatively small differences in syscall performance between windows and +linux can add up. + +I've looked at just this kind of comparisons before, and it has always +seemed explainable by differences in syscall overhead. I don't +really see anything in your numbers that says otherwise. + +I'm still curious if there's an older version of git-annex that was faster +(after it stopped using direct mode in v7). +If I've understood correctly, you don't seem to be saying that there is. + +If it's always been this slow, then about all I can think to do to improve +it is profile git-annex smudge --clean on windows and see if anything other +than those syscalls is somehow being slow. +"""]]