Re: [PATCH/RFC] base-files: add noatime to rootfs mount options

[Dmitry Artamonow <mad_soft@inbox.ru>]

On 14:53 Sat 04 Apr     , Otavio Salvador wrote:
> On Sat, Apr 4, 2009 at 6:09 AM, Dmitry Artamonow <mad_soft@inbox.ru> wrote:
> > On 13:48 Sun 29 Mar     , Koen Kooi wrote:
> >> On 15-03-09 21:47, Dmitry Artamonow wrote:
> [...]
> >>> Fix it by adding noatime to rootfs mount options in fstab.
> >>
> >> Isn't 'relatime' a better option?
> >
> > Maybe yes, but we need more care in this case, because relatime has
> > been introduced in 2.6.20 [1], and there's still can be machines using
> > older kernels (judging solely by looking at the recipes in recipes/linux).
> > I fear that we may break booting on these machines by passing
> > unsupported option to mount.
> >
> > [1] http://kernelnewbies.org/Linux_2_6_20#head-6804816ab4f07548635032afbedd3e1f4eb3d1d7
> 
> I belive that if those machines still uses old kernels they have the
> responsability to deal with those things; besides that it is very
> common for machines to provide custom fstab files so it won't
> hurt to put a specific one to workaround it if required.

In case with default fstab - yes, probably you are right, since it can
be easily overrided by custom version for specific machine/distro.
But we need to carefully check which of the pre-existing
machine-specific fstabs can be modified to use relatime.

I've made some investigations by running this script:
 ls recipes/base-files/base-files/*/fstab | cut -d/ -f4 | \
 while read MACHINE  ; do echo $MACHINE; \
 bitbake -c setscene -n -vv virtual/kernel | grep setscene ; done
and then reformatting output by hand. Here's the results
(checked with Angstrom distro):

akita		linux-rp_2.6.26.bb
amsdelta	linux-amsdelta-2.6_2.6.16-omap2.bb
armzone-qt2410
c7x0		linux-rp_2.6.26.bb
efika		linux-rt_2.6.25.bb
ep93xx		linux_2.6.29+2.6.30-rc1.bb
epia		linux-epia_2.6.19.2.bb
gumstix-connex	gumstix-kernel_2.6.21.bb
gumstix-verdex	gumstix-kernel_2.6.21.bb
h2200		linux-handhelds-2.6_2.6.21-hh20.bb
h3600		linux-handhelds-2.6_2.6.21-hh20.bb
h3900		linux-handhelds-2.6_2.6.21-hh20.bb
h5000		linux-handhelds-2.6_2.6.21-hh20.bb
h6300		linux-h6300-omap1_2.6.16.16.bb
htcuniversal	linux-handhelds-2.6_2.6.21-hh20.bb
hx4700		linux-handhelds-2.6_2.6.21-hh20.bb
jornada56x	linux-handhelds-2.6_2.6.21-hh20.bb
jornada6xx	linux-jlime-jornada6xx_2.6.25.bb
jornada7xx	linux-jlime-jornada7xx_2.6.19rc6.bb
mtx-1		linux-mtx-1_2.4.27.bb
mtx-2		linux-mtx-2_2.4.27.bb
mx31moboard	linux_2.6.22.6.bb
netbook-pro	netbook-pro-kernel_2.6.17.bb
netvista	linux_2.6.23.bb
nokia770	linux-nokia800_2.6.18-osso40.bb
om-3d7k		linux-openmoko-devel_git.bb
om-gta01	linux-openmoko-2.6.24_git.bb
om-gta02	linux-openmoko-2.6.28_git.bb
omap5912osk	linux-omap_2.6.28.bb
openmn
openprotium
poodle		linux-rp_2.6.24.bb
simpad		linux_2.6.24.bb
slugos
spitz		linux-rp_2.6.26.bb
tosa		linux_2.6.29.bb
wrt54		linux-wrt_2.4.30.bb
xxs1500		linux-xxs1500_2.4.21.bb

As you can see there's still a lot of machines with 2.6.19, 2.6.16 and
even 2.4 kernels.

Anyway, I've redone patch by leaving out fstab for machines with
kernel <2.6.20 and also non-machine-fstabs (probably distro-specific -
openmn, openprotium, slugos, armzone-qt2410).

I'll send current version in following mail.

-- 
Best regards,
Dmitry "MAD" Artamonow