[OE-core] [RFC 1/2] IMAGE_ROOTFS_SIZE Cleanup
Joshua Lock
josh at linux.intel.com
Thu May 26 21:01:23 UTC 2011
On Thu, 2011-05-26 at 13:55 -0700, Darren Hart wrote:
>
> On 05/26/2011 12:54 PM, Joshua Lock wrote:
> > On Thu, 2011-05-26 at 11:28 -0700, Saul Wold wrote:
> >> On 05/26/2011 11:04 AM, Joshua Lock wrote:
> >>> On Mon, 2011-05-23 at 23:38 -0700, Saul Wold wrote:
> >>>> This basic cleanup removes the _ext2/3 overrides from places they
> >>>> no longer belong since they did not allow further overrides. In doing
> >>>> this the core-image-minimal* recipes can now set a reasonably small
> >>>> rootfs so that it's a realistic size for minimal.
> >>>
> >>> Awesome. Thanks for tackling this!
> >>>
> >>> Few questions below.
> >>>
> >>>>
> >>>> The new default for minimal is 8M and will be adujsted upward by the
> >>>> IMAGE_OVERHEAD_FACTOR (of 1.2).
> >>>>
> >>>> This fixes the ROOTFS_SIZE usage in the IMAGE_CMD_<fstype> code
> >>>>
> >>>> Signed-off-by: Saul Wold<sgw at linux.intel.com>
> >>>> ---
> >>>> meta/classes/image_types.bbclass | 7 +++++--
> >>>> meta/conf/distro/include/default-distrovars.inc | 2 --
> >>>> meta/conf/machine/include/qemu.inc | 2 --
> >>>> .../images/core-image-minimal-initramfs.bb | 2 ++
> >>>> meta/recipes-core/images/core-image-minimal.bb | 2 ++
> >>>> 5 files changed, 9 insertions(+), 6 deletions(-)
> >>>>
> >>>> diff --git a/meta/classes/image_types.bbclass b/meta/classes/image_types.bbclass
> >>>> index ec0cafd..69f859e 100644
> >>>> --- a/meta/classes/image_types.bbclass
> >>>> +++ b/meta/classes/image_types.bbclass
> >>>> @@ -21,22 +21,25 @@ runimagecmd () {
> >>>> }
> >>>>
> >>>> IMAGE_CMD_jffs2 = "mkfs.jffs2 --root=${IMAGE_ROOTFS} --faketime --output=${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.jffs2 ${EXTRA_IMAGECMD}"
> >>>> +
> >>>> IMAGE_CMD_cramfs = "mkcramfs ${IMAGE_ROOTFS} ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.cramfs ${EXTRA_IMAGECMD}"
> >>>> +
> >>>> IMAGE_CMD_ext2 = "genext2fs -b $ROOTFS_SIZE -d ${IMAGE_ROOTFS} ${EXTRA_IMAGECMD} ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.ext2"
> >>>> IMAGE_CMD_ext2.gz () {
> >>>> rm -rf ${DEPLOY_DIR_IMAGE}/tmp.gz&& mkdir ${DEPLOY_DIR_IMAGE}/tmp.gz
> >>>> - genext2fs -b ${IMAGE_ROOTFS_SIZE} -d ${IMAGE_ROOTFS} ${EXTRA_IMAGECMD} ${DEPLOY_DIR_IMAGE}/tmp.gz/${IMAGE_NAME}.rootfs.ext2
> >>>> + genext2fs -b $ROOTFS_SIZE -d ${IMAGE_ROOTFS} ${EXTRA_IMAGECMD} ${DEPLOY_DIR_IMAGE}/tmp.gz/${IMAGE_NAME}.rootfs.ext2
> >>>> gzip -f -9 ${DEPLOY_DIR_IMAGE}/tmp.gz/${IMAGE_NAME}.rootfs.ext2
> >>>> mv ${DEPLOY_DIR_IMAGE}/tmp.gz/${IMAGE_NAME}.rootfs.ext2.gz ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.ext2.gz
> >>>> rmdir ${DEPLOY_DIR_IMAGE}/tmp.gz
> >>>> }
> >>>> +
> >>>> IMAGE_CMD_ext3 () {
> >>>> genext2fs -b $ROOTFS_SIZE -d ${IMAGE_ROOTFS} ${EXTRA_IMAGECMD} ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.ext3
> >>>> tune2fs -j ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.ext3
> >>>> }
> >>>> IMAGE_CMD_ext3.gz () {
> >>>> rm -rf ${DEPLOY_DIR_IMAGE}/tmp.gz&& mkdir ${DEPLOY_DIR_IMAGE}/tmp.gz
> >>>> - genext2fs -b ${IMAGE_ROOTFS_SIZE} -d ${IMAGE_ROOTFS} ${EXTRA_IMAGECMD} ${DEPLOY_DIR_IMAGE}/tmp.gz/${IMAGE_NAME}.rootfs.ext3
> >>>> + genext2fs -b $ROOTFS_SIZE -d ${IMAGE_ROOTFS} ${EXTRA_IMAGECMD} ${DEPLOY_DIR_IMAGE}/tmp.gz/${IMAGE_NAME}.rootfs.ext3
> >>>> tune2fs -j ${DEPLOY_DIR_IMAGE}/tmp.gz/${IMAGE_NAME}.rootfs.ext3
> >>>> gzip -f -9 ${DEPLOY_DIR_IMAGE}/tmp.gz/${IMAGE_NAME}.rootfs.ext3
> >>>> mv ${DEPLOY_DIR_IMAGE}/tmp.gz/${IMAGE_NAME}.rootfs.ext3.gz ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.ext3.gz
> >>>> diff --git a/meta/conf/distro/include/default-distrovars.inc b/meta/conf/distro/include/default-distrovars.inc
> >>>> index 1aa45c8..4b68a0a 100644
> >>>> --- a/meta/conf/distro/include/default-distrovars.inc
> >>>> +++ b/meta/conf/distro/include/default-distrovars.inc
> >>>> @@ -1,7 +1,5 @@
> >>>> QA_LOGFILE = "${TMPDIR}/qa.log"
> >>>>
> >>>> -IMAGE_ROOTFS_SIZE_ext2 ?= "131072"
> >>>> -
> >>>> OEINCLUDELOGS ?= "yes"
> >>>> KERNEL_CONSOLE ?= "ttyS0"
> >>>>
> >>>> diff --git a/meta/conf/machine/include/qemu.inc b/meta/conf/machine/include/qemu.inc
> >>>> index 4122a88..9ef242f 100644
> >>>> --- a/meta/conf/machine/include/qemu.inc
> >>>> +++ b/meta/conf/machine/include/qemu.inc
> >>>> @@ -6,8 +6,6 @@ MACHINE_FEATURES = "kernel26 apm alsa pcmcia bluetooth irda usbgadget screen"
> >>>> IMAGE_FSTYPES ?= "tar.bz2 ext3"
> >>>>
> >>>> ROOT_FLASH_SIZE = "280"
> >>>> -IMAGE_ROOTFS_SIZE_ext2 ?= "280000"
> >>>> -IMAGE_ROOTFS_SIZE_ext3 ?= "280000"
> >>>>
> >>>> # Don't include kernels in standard images
> >>>> RDEPENDS_kernel-base = ""
> >>>> diff --git a/meta/recipes-core/images/core-image-minimal-initramfs.bb b/meta/recipes-core/images/core-image-minimal-initramfs.bb
> >>>> index 21aaa6c..3246d5c 100644
> >>>> --- a/meta/recipes-core/images/core-image-minimal-initramfs.bb
> >>>> +++ b/meta/recipes-core/images/core-image-minimal-initramfs.bb
> >>>> @@ -8,3 +8,5 @@ IMAGE_LINGUAS = ""
> >>>> LICENSE = "MIT"
> >>>>
> >>>> inherit core-image
> >>>> +
> >>>> +IMAGE_ROOTFS_SIZE = "8192"
> >>>
> >>> I'm not really sure about this, an initramfs that's the same size as a
> >>> more fully featured rootfs?
> >>>
> >> That may be, then we need to increase the size slightly, but this will
> >> trigger the correct behavior of actual size * IMAGE_OVERHEAD_FACTOR,
> >> rather than the 64M which would be the default, this was to ensure it
> >> could get smaller. I don't have a current initramfs size, I will build
> >> and verify.
> >>
> >>
> >>>> diff --git a/meta/recipes-core/images/core-image-minimal.bb b/meta/recipes-core/images/core-image-minimal.bb
> >>>> index aa00e67..743e121 100644
> >>>> --- a/meta/recipes-core/images/core-image-minimal.bb
> >>>> +++ b/meta/recipes-core/images/core-image-minimal.bb
> >>>> @@ -9,5 +9,7 @@ LICENSE = "MIT"
> >>>>
> >>>> inherit core-image
> >>>>
> >>>> +IMAGE_ROOTFS_SIZE = "8192"
> >>>> +
> >>>
> >>> In your cover letter you stated that the minimal image is currently
> >>> 9.9M, which means we *need* the overhead to contain the entire image
> >>> contents. Correct? That seems a little unwise.
> >>>
> >> Right, that's currently, we want to see the image get smaller even, so
> >> the 8M is an appropriate setting. Currently the actual ext3 image is
> >> 13M with 10M of contents.
> >>
> >> So are you suggested that the 8M size is unwise or the overhead, not
> >> sure I am catching your meaning here.
> >
> > I'm just nervous about relying on the overhead, what if someone sets it
> > lower and then the image doesn't fit?
> >
> > Having the goal of a smaller minimal image is good but in my opinion we
> > should adjust the rootfs size when the image is smaller, not before.
>
> Every argument I've heard in favor of the IMAGE_OVERHEAD was centered
> around ensuring there is enough space for the user to actually use the
> system after it was installed and booted. Using this single metric to
> try and both make up for oversized images and provide space for user
> data seems like to cause maintenance issues going forward.
>
> While our goal should be to reduce the image size, the default image
> size in the recipes should default to the largest of the images built
> for the supported machines. The overhead should be used strictly for
> user data.
>
So it turns out that if IMAGE_ROOTFS is smaller than the contents the
size of the contents is used. Once this if test has been performed the
overhead factor is applied.
I found this to be a tad confusing (hence all the back and forth here)
so have filed a documentation bug about it:
http://bugzilla.pokylinux.org/show_bug.cgi?id=1110
Maybe we can have some comments in the code near where those variables
are set too?
--
Joshua Lock
Yocto Project Build Monkey
Intel Open Source Technology Centre
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