Re: [PATCH v2 0/6] tmpfs: add the option to disable swap

From: Hugh Dickins
Date: Tue Apr 18 2023 - 00:31:39 EST


On Thu, 9 Mar 2023, Luis Chamberlain wrote:

> I'm doing this work as part of future experimentation with tmpfs and the
> page cache, but given a common complaint found about tmpfs is the
> innability to work without the page cache I figured this might be useful
> to others. It turns out it is -- at least Christian Brauner indicates
> systemd uses ramfs for a few use-cases because they don't want to use
> swap and so having this option would let them move over to using tmpfs
> for those small use cases, see systemd-creds(1).

Thanks for your thorough work on tmpfs "noswap": seems well-received
by quite a few others, that's good.

I've just a few comments on later patches (I don't understand why you
went into those little rearrangements at the start of shmem_writepage(),
but they seem harmless so I don't object), but wanted to ask here:

You say "a common complaint about tmpfs is the inability to work without
the page cache". Ehh? I don't understand that at all, and have never
heard such a complaint. It doesn't affect the series itself (oh, Andrew
has copied that text into the first patch), but please illuminate!

Thanks,
Hugh