[9fans] fossil option -m

[arisawa]

Helo,

Plan 9 manual FOSSIL(4) says about fossil/fossil command option -m:
-m Allocate free-memory-percent percent of the avail-
able free RAM for buffers. This overrides all other
memory sizing parameters, notably the -c option to
open.
How to give memory, for example 25%, to fossil in starting 9pcf or 9pccpuf kernel?
I think the value should be enabled to be given in plan9.ini, but I couldn't find in the manual PLAN9.INI(8).

Kenji Arisawa

[erik quanstrom]

Post by arisawa
Helo,
-m Allocate free-memory-percent percent of the avail-
able free RAM for buffers. This overrides all other
memory sizing parameters, notably the -c option to
open.
How to give memory, for example 25%, to fossil in starting 9pcf or 9pccpuf kernel?
I think the value should be enabled to be given in plan9.ini, but I couldn't find in the manual PLAN9.INI(8).

if you're using standard plan 9 boot stuff, you'll need to hack boot/local.c
right under the /* start fossil */ comment, or fossil itself. personally, i'd lean
toward adding an environment variable which could be put into plan9.ini
and be the equivalent of -m.

- erik

[John Floren]

Post by erik quanstrom

Post by arisawa
Helo,
-m Allocate free-memory-percent percent of the avail-
able free RAM for buffers. This overrides all other
memory sizing parameters, notably the -c option to
open.
How to give memory, for example 25%, to fossil in starting 9pcf or 9pccpuf kernel?
I think the value should be enabled to be given in plan9.ini, but I couldn't find in the manual PLAN9.INI(8).

if you're using standard plan 9 boot stuff, you'll need to hack boot/local.c
right under the /* start fossil */ comment, or fossil itself. personally, i'd lean
toward adding an environment variable which could be put into plan9.ini
and be the equivalent of -m.
- erik

You can also use a boot.fs kernel, so you can define the startup in an
rc script. Very convenient, I used it to set up our
cpu/auth/fileserver to use a Coraid AoE device for Venti.

John

[arisawa]

Thanks Erik and John,

It seems the option value -m is 20 by default.
/sys/src/9/boot/local.c in Plan9:
run("/boot/fossil", "-m", "20", "-f", partition,
"-c", "srv -A fboot", "-c", "srv -p fscons", nil);

I have looked contents in /boot/bootfs.paq of 9front.
I like the booting process: flexible, elegant and probably powerful.

[Richard Miller]

Post by arisawa
I have looked contents in /boot/bootfs.paq of 9front.
I like the booting process: flexible, elegant and probably powerful.

Using a shell script to control booting has been around for a while:

--rwxrwxr-x M 12 sys sys 568 Feb 3 2005 /sys/lib/sysconfig/blast/boot

[erik quanstrom]

Post by arisawa
I have looked contents in /boot/bootfs.paq of 9front.
I like the booting process: flexible, elegant and probably powerful.

it's another stage of bootloading which requires a number of things to be built-in
to the kernel. in this sense, it's like initrd.

if we were to instead make the local file servers (fossil+venti, kfs, cwfs, etc.)
idiomatic enough in their arguments, it should be easy enough to drive them
with the same boot code, that needn't bloat the kernel, or require fancy
memory reclaim.

also,

Post by arisawa
let's make it "fsmb". that way we need not enumerate file servers.
i've always found listing things in mb is easier to work out.

i take it back. $fsname^mb is idiomatic enough to automate.
sorry for the noise.

- erik

[c***@gmx.de]

term% cat /sys/src/9/port/bootfs.proto
$objtype
bin
9660srv
awk
aux
kbdfs
bind
cat
cfs
cryptsetup
dd
disk
fdisk
kfs
prep
dossrv
echo
cwfs64x
grep
ip
ipconfig
ls
mkdir
mntgen
mount
mv
hjfs
rc
rm
sed
sleep
srv
test
unmount
nusb
usbd
disk
kb
xd
rc
lib
rcmain
local.rc 555 sys sys ../boot/local.rc
net.rc 555 sys sys ../boot/net.rc
bin
fstype
diskparts
nusbrc 555 sys sys ../boot/nusbrc
bootrc 555 sys sys ../boot/bootrc
tmp

the resulting bootfs.paq is 1.2 MB.

theres no reclaim. if init dies you get back to the bootrc
"bootargs" prompt.

for comparsion, drawing a 1024x768x32 rio window would be
like 3MB of precious kernel memory.

making fileservers idiomatic is a good idea. thats exactly
what i did with cwfs making it look like kfs. fossil/venti
is the only filesystem that requires special boot code.
(which does not matter in 9front as fossil was removed).

--
cinap

[erik quanstrom]

Post by c***@gmx.de
for comparsion, drawing a 1024x768x32 rio window would be
like 3MB of precious kernel memory.

not an apples-to-apples comparison. devdraw images are
reclaimable and compactable. and does init paqfs exit or not?
that's another 10mb. but memory use is really beside the point.

i think the rc booting travels a conceptually greater distance
between the kernel starting the first process and being fully
functional & configured kernel. this is a cost that for me
outweighs the benefits. and anyway, it's code either way.
the fact that it's rc and not c doesn't change the fact its built
into the kernel.

btw, is there any way to identify programs started from the init paq?
this is an additional 30 odd programs built into the kernel beyond
ipconfig and factotum. (why aren't they part of the init paq?)
and i wonder if there couldn't be some confusion.

- erik

[c***@gmx.de]

nope. paqfs doesnt exit. and its not wasting 10mb.

term% ps -a | grep paq
cinap_lenrek 5 0:00 0:00 188K Pread paqfs

yes, bootrc basicly does the same stuff as the c based /boot/boot
did before. we found that the other 30 odd programs can come in handy.
especially when you try to boot a kernel on a odd machines where
theres no working disks (yet :-)).

the odd machines tend to be owned by people new to plan9 and
being short of patience for getting a pxe setup or attach
serial cables to the machine. but asking them to break into rc
and getting some readout of some ctl files works fine.

ipconfig *is* part of bootfs.paq.

term% ls -l /boot
--r-xr-xr-x / 0 cinap_lenrek cinap_lenrek 29306 Aug 16 10:57 /boot/boot
--r-xr-xr-x / 0 cinap_lenrek cinap_lenrek 1327174 Aug 16 10:57 /boot/bootfs.paq
--r-xr-xr-x / 0 cinap_lenrek cinap_lenrek 241755 Aug 16 10:57 /boot/factotum
--r-xr-xr-x / 0 cinap_lenrek cinap_lenrek 72165 Aug 16 10:57 /boot/paqfs

factotum is not build into the paq because libauth's auth_getkeys()
execs "/boot/factotum" to ask for passwords/keys. changing that would
break old binaries.

--
cinap

[Richard Miller]

Post by c***@gmx.de
yes, bootrc basicly does the same stuff as the c based /boot/boot
did before. we found that the other 30 odd programs can come in handy.
especially when you try to boot a kernel on a odd machines where
theres no working disks (yet :-)).

Yes, I've found the same approach useful while developing an sd/mmc
card driver for the raspberry pi. I started with this inital boot.rc:

#!/boot/rc -m /boot/rcmain

/boot/echo boot...
/boot/bind -c /boot /bin
bind '#p' /proc
bind '#d' /fd
bind -a '#P' /dev
bind -a '#t' /dev
bind -a '#S' /dev
echo -n rpi >/dev/hostowner
echo fdisk...
fdisk -p /dev/sdM0/data >/dev/sdM0/ctl
cat /dev/sdM0/ctl
dossrv -f/dev/sdM0/dos
mount -c /srv/dos /mnt
exec /boot/rc -m/boot/rcmain -i

And for sd driver testing there's no need for a paqfs - a handful
of useful programs can just be stuck into /boot directly:

bootdir
boot.rc boot
/arm/bin/rc
/rc/lib/rcmain
/arm/bin/mount
/arm/bin/unmount
/arm/bin/bind
/arm/bin/echo
/arm/bin/cat
/arm/bin/cmp
/arm/bin/ls
/arm/bin/ps
/arm/bin/dd
/arm/bin/xd
/arm/bin/rm
/arm/bin/mkdir
/arm/bin/disk/fdisk
/arm/bin/dossrv

But all this is now obsolete [see next message].

[Richard Miller]

Post by erik quanstrom
personally, i'd lean
toward adding an environment variable which could be put into plan9.ini
and be the equivalent of -m.

How about
*fossilpercent=NN
*ventipercent=NN
*kfspercent=NN
Any others?

I'll do a patch if nobody objects. Needs a change to kfs to add '-m' option.

[David du Colombier]

Post by Richard Miller
How about
*fossilpercent=NN
*ventipercent=NN
*kfspercent=NN
Any others?
I'll do a patch if nobody objects. Needs a change to kfs to add '-m' option.

Yes. I think it's a good idea.
But maybe without the leading '*', since they
aren't kernel parameters.

[Richard Miller]

Post by David du Colombier
But maybe without the leading '*', since they
aren't kernel parameters.

Probably right, although it's never been clear to me why some things
have '*' and some don't. For example etherN=XXXXX is used only by
the kernel, but it still gets passed in the normal '#e' environment
to processes.

On further thought, what about generalising a bit more: plan9.ini(8)
already has
factotumopts=options
Causes boot(8) to start factotum with the given options,

If we allowed XXXXopts=options, where XXXX is the name of any command
in /boot, my earlier suggestion would be just a particular case of this
with
fossilopts=-m NN
ventiopts=-m NN

Is this a simplification or a complication?

I'd actually prefer 'fossil-opts=-M NN' , but we already have the
precedent of factotumopts.

[erik quanstrom]

Post by Richard Miller
Probably right, although it's never been clear to me why some things
have '*' and some don't. For example etherN=XXXXX is used only by
the kernel, but it still gets passed in the normal '#e' environment
to processes.

i'd say that it's a bit of parsimony that we didn't get right.
quite similar in its dog-always-on-wrong-side-of-door nature
to bourne shell's "export".

Post by Richard Miller
How about
*fossilpercent=NN
*ventipercent=NN
*kfspercent=NN

let's make it "fsmb". that way we need not enumerate file servers.
i've always found listing things in mb is easier to work out.

maybe i'm applying bad experiences with percentage-based partitions,
and *kernelpercent incorrectly.

(if i have *kernelpercent=9 or 10 and 3000mb of memory, how much
kernel memory do i get and why? how much memory would i
get if i specified nothing? i think the answer is 73.8125mb any
way for a cpu server, and 256mb for a terminal, using the distribution's
algorithms.)

- erik

[David du Colombier]

Post by arisawa
let's make it "fsmb". that way we need not enumerate file servers.

Just wondering. How do you distinguish between Fossil
and Venti, when they are running on the same machine?
They have very different memory requirement.

[erik quanstrom]

Post by David du Colombier

Post by arisawa
let's make it "fsmb". that way we need not enumerate file servers.

Just wondering. How do you distinguish between Fossil
and Venti, when they are running on the same machine?
They have very different memory requirement.

i retracted this suggestion yesterday. not only for the reason you
point out, but also because if we generalize the kfs, fossil code
to bootlocalfses, $($fsname)mb seems the obvious choice.

- erik

[Bakul Shah]

Post by erik quanstrom

Post by David du Colombier

Post by arisawa
let's make it "fsmb". that way we need not enumerate file servers.

Just wondering. How do you distinguish between Fossil
and Venti, when they are running on the same machine?
They have very different memory requirement.

i retracted this suggestion yesterday. not only for the reason you
point out, but also because if we generalize the kfs, fossil code
to bootlocalfses, $($fsname)mb seems the obvious choice.

What's mb? Milli bits?

[c***@gmx.de]

millerbytes :)

--
cinap

[erik quanstrom]

Post by Bakul Shah
What's mb? Milli bits?

micro baud.

- erik

[erik quanstrom]

Post by John Floren
You can also use a boot.fs kernel, so you can define the startup in an
rc script. Very convenient, I used it to set up our
cpu/auth/fileserver to use a Coraid AoE device for Venti.

you can do that with the usual scripts with 9atom. it requires setting
"aoeif=<list>" and "aoedev=<list>". see the manual pages.

- erik

[erik quanstrom]

Post by erik quanstrom

Post by John Floren
You can also use a boot.fs kernel, so you can define the startup in an
rc script. Very convenient, I used it to set up our
cpu/auth/fileserver to use a Coraid AoE device for Venti.

you can do that with the usual scripts with 9atom. it requires setting
"aoeif=<list>" and "aoedev=<list>". see the manual pages.

s:scripts:boot code:

- erik

[Richard Miller]

millerbytes :)

No, he only barks occasionally.