Re: Working on Discard for FFS

[christos%astron.com@localhost (Christos Zoulas)]

In article <CAO5QJJVT65VAy7rsqK8jGCj_h8ipwyMYD5dkukO8cgV+RsjUoQ%mail.gmail.com@localhost>,
Joshua Gillett  <joshuagillett%college.harvard.edu@localhost> wrote:
>-=-=-=-=-=-
>
>tech-kern,
>
>I wanted to follow up. Iâ??m interesting in doing some work on this and
>wanted to know the feasibility of and if there was any more information
>pertaining to the project.
>
>Best wishes,
>Joshua Gillett
>Harvard College â??27
>A.B. Candidate in Computer Science

Hi Joshua,

There is some low level support in NetBSD for trim in the device drivers
(wd for example), but there is no ioctl interface, filesystem support and
of course no userland trim utility. I would check out how FreeBSD does it
first and model it after that. I would start with ioctl support, then
userland utility support to test and finally I would start adding support
to ffs. I think that we would need to update our zfs code to support trim.

Best,

christos