On Wed, May 26, 2021 at 04:33:00PM +0800, Menglong Dong wrote: > On Wed, May 26, 2021 at 12:33 PM Josh Triplett <josh@xxxxxxxxxxxxxxxx> wrote: > > > > On Tue, May 25, 2021 at 10:23:09PM -0500, Eric W. Biederman wrote: > > > If we are going to do this something that is so small and clean it can > > > be done unconditionally always. > > [...] > > > The net request as I understand it: Make the filesystem the initramfs > > > lives in be an ordinary filesystem so it can just be used as the systems > > > primary filesystem. > > > > Including the ability to pivot_root it away, which seems like the main > > sticking point. > > > > If this can be done without any overhead, that seems fine, but if this > > involves mounting an extra filesystem, that may add an appreciable > > amount of boot time for systems trying to boot in milliseconds. (Such > > systems would not use an initramfs if they're going to go on and boot a > > separate root filesystem, but they can use an initramfs as their *only* > > filesystem.) > > Compared to the time the unpacking spent, a mounting seems nothing. In the > scene above, this change can be disabled by kconfig, if pivot_root > is not needed in initramfs. I asked for the kconfig entry. And it would be good to document then also the worst case expected on boot for what this could do to you. I mean, we are opening a different evil universe. So that's why the kconfig exists. How bad and evil can this be? I don't think anyone has clarified that yet. Luis
