Re: Stressing malloc(9)

On Tue, Apr 23, 2024 at 7:30 AM Alexander Leidinger <Alexander@leidinger.net>
wrote:

> Am 2024-04-23 14:47, schrieb Alan Somers:
> > On Tue, Apr 23, 2024 at 2:37 AM Alexander Leidinger
> > <Alexander@leidinger.net> wrote:
>
> >> You basically say, that it is not uncommon to have such large
> >> allocations with kernels we ship (even in releases).
> >> Wouldn't it make sense to optimize the kernel to handle larger uma
> >> allocations?
> >>
> >> Or do you expect it to be specific to ZFS and it may be more sane to
> >> discuss with the OpenZFS developers to reduce this default setting?
> >
> > Yes, both of those things are true.  It might make sense to reduce the
> > setting's default value.  OTOH, the current value is probably fine for
> > people who don't use geli (and possibly other transforms that require
> > allocating data).  And it would also be good to optimize the kernel to
> > perform these allocations more efficiently.  My best idea is to teach
> > g_eli_alloc_data how to allocate scatter/gather lists of 64k buffers
> > instead of contiguous memory.  The memory doesn't need to be
> > contiguous, after all.  But that's a bigger change, and I don't know
> > that I have the time for it right now.
> > -Alan
>
> Do you have time do make a nice description of what would have to be
> done in the wiki?
>      https://wiki.freebsd.org/IdeasPage


I've added the super-brief verrsion to https://wiki.freebsd.org/WarnerLosh
which has my crazy ideas list...

Warner