From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Weinberger Date: Sat, 03 Nov 2018 10:10:08 +0100 Message-ID: <3624012.MiIzIq7dko@blindfold> In-Reply-To: <20181103035341.16893-1-helen.koike@collabora.com> References: <20181103035341.16893-1-helen.koike@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [linux-lvm] [PATCH v10 0/2] dm: boot a mapped device without an initramfs Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: To: Helen Koike , keescook@chromium.org Cc: wad@chromium.org, snitzer@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, linux-lvm@redhat.com, enric.balletbo@collabora.com, kernel@collabora.com, agk@redhat.com Helen, Am Samstag, 3. November 2018, 04:53:39 CET schrieb Helen Koike: > As mentioned in the discussion from the previous version of this patch, Android > and Chrome OS do not use initramfs mostly due to boot time and size liability. Do you have numbers on that? I understand that using something like dracut with systemd inside is not what you want from a boot time point of view. But having an initramfs embedded into the kernel image which contains only a single static linked binary can be *very* small and fast. If you invest a little more time, you don't even need a libc, just fire up some syscalls to setup your dm. I use this technique regularly on deeply embedded systems to setup non-trivial UBIFS/crypto stuff. Want I'm trying to say, before adding ad-hoc a feature to the kernel, we should be very sure that there is no other way to solve this in a sane manner. We have initramfs support for reasons. Thanks, //richard