On Sat, Nov 2, 2019 at 3:03 PM Linus Torvalds
[off-list ref] wrote:

On Sat, Nov 2, 2019 at 1:31 PM Andy Lutomirski [off-list ref] wrote:

quoted

Add in the fact that it’s not obvious that vmsplice *can* be used correctly, and I’m wondering if we should just remove it or make it just do write() under the hood.

Sure it can. Just don't modify the data you vmsplice. It's really that simple.

That said, if we don't have any actual users, then we should look at
removing it (maybe turning it into "write()" as you say). Not because
it's hard to use, but simply because it probably doesn't have that
many uses.

Looking at debian code search, there are _some_ uses (including
openssl and fuse):

  https://codesearch.debian.net/search?q=%3D+vmsplice%28&literal=1

but I didn't check any more closely what they do.

             Linus