From 03f46b95e69afee47f37530068f8783cf65351c0 Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Thu, 13 May 2021 12:05:24 -0400 Subject: [PATCH] comment --- ..._5097e4ac096d1b0b9c06c544b9217e22._comment | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 doc/todo/support_macOS__39___cp_-c___40__cp_--reflink_equivalent__41__/comment_9_5097e4ac096d1b0b9c06c544b9217e22._comment diff --git a/doc/todo/support_macOS__39___cp_-c___40__cp_--reflink_equivalent__41__/comment_9_5097e4ac096d1b0b9c06c544b9217e22._comment b/doc/todo/support_macOS__39___cp_-c___40__cp_--reflink_equivalent__41__/comment_9_5097e4ac096d1b0b9c06c544b9217e22._comment new file mode 100644 index 0000000000..a1f1e67f93 --- /dev/null +++ b/doc/todo/support_macOS__39___cp_-c___40__cp_--reflink_equivalent__41__/comment_9_5097e4ac096d1b0b9c06c544b9217e22._comment @@ -0,0 +1,19 @@ +[[!comment format=mdwn + username="joey" + subject="""comment 9""" + date="2021-05-13T15:51:41Z" + content=""" +fork/exec can end up being fairly significant overhead when the files are +small enough. And, at least on linux systems, most people are probably not +using a filesystem supporting CoW, so most people would pay that perf +penalty. That's why the current code is optimised to avoid it, +at least in places where it's seemed worthwhile. + +I'll suggest again: Just start with copyCoW, leave copyFileExternal +not doing CoW copies, I'll accept that easy patch. And then if any of +the 6 or so call sites of copyFileExternal end up being ones you want to +make support CoW on OSX, convert them to use tryCopyCoW. + +(Alternatively, if there were a haskell library that provided the syscall +that does a CoW copy, it could just use it.) +"""]] -- 2.30.2