Re: [Q] don't allow tmpfs to page out

From: christophe . varoqui
Date: Thu Jul 15 2004 - 05:03:08 EST


Selon Arjan van de Ven <arjanv@xxxxxxxxxx>:

>
> On Thu, Jul 15, 2004 at 09:58:37AM +0200, christophe.varoqui@xxxxxxx wrote:
> > >
> > > just do
> > > mount -t ramfs none /mnt/point
> > >
> > Would that be a suitable solution to store callout binaries for daemons
> like
> > multipathd that need to work in case of system-disk outage (/bin & swap on
> SAN
> > for example) ?
>
> somewhat, as long as ALL requirements are there, including all libraries ;)
>
ok, sure.
klibc linked static binaries in my case (scsi_id & multipath), so it should be ok.

> > If so, is it possible and/or correct for the daemon to do a private ramfs
> mount
> > for this purpose ?
>
> sure; namespaces can do a LOT

Somehow "man 2 mount" is not so verbose about that "lot" :)
Can you feed a pointer to a doc explaining how to achieve such privacy ?

> >
> > And while I'm at throwing all the questions I have on my mind :
> > * how can I disable on-demand loading for the daemon ?
> > * does mlockall() provides all the necessary garanties ?
>
> mlockall does not guarantee that syscalls you do don't cause memory
> allocations, nor does the ramfs approach.
>
mmm ... more questions than I had before :)
any hint about how to solve this issue ?

regards,
cvaroqui


--
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/