On 30.08.2022 11:02, Rick Macklem wrote:
Mateusz Guzik <[email protected]> wrote:
On 8/30/22, Alexander Motin <[email protected]> wrote:
The branch main has been updated by mav:
URL:
https://cgit.FreeBSD.org/src/commit/?id=35b7759c05cbc65c06d87141da79f0f80af0f458
commit 35b7759c05cbc65c06d87141da79f0f80af0f458
Author: Alexander Motin <[email protected]>
AuthorDate: 2022-08-30 14:51:21 +0000
Commit: Alexander Motin <[email protected]>
CommitDate: 2022-08-30 14:51:21 +0000
cp: Fix build without VM_AND_BUFFER_CACHE_SYNCHRONIZED.
It allows to not use mmap() for small files, which is not helpful
in case of ZFS. Should be no functional change.
This should be of no use thanks to copy_file_range
cp does not use copy_file_range(2) for small files, if I recall correctly.
Right. I tried to look for motivation, but history of this file goes
back to 4.4 Lite. :) I wonder whether copy_file_range(2) for UFS does
something clever, like this mmap() to avoid additional memory copy. For
ZFS though it cause big problem with buffer cache squeezing ARC to
absolute minimum. So if there is agreement to modernize this, I'd
completely support it.
--
Alexander Motin
