* Re: Kernel 2.6 size increase
[not found] ` <fnHd.54o.19@gated-at.bofh.it>
@ 2003-07-31 16:31 ` Ihar "Philips" Filipau
2003-07-31 16:43 ` Tom Rini
0 siblings, 1 reply; 16+ messages in thread
From: Ihar "Philips" Filipau @ 2003-07-31 16:31 UTC (permalink / raw)
To: Tom Rini; +Cc: Linux Kernel Mailing List
Tom Rini wrote:
>
> Power Management, sysfs plays / will play a role in finding out the order
> in which devices get powered down. This is important on some types of
> embedded devices (and arguably important everywhere).
>
You are contradicting to yourself.
I have participated in creation of two specialized embedded systems,
and currently going into third one.
Every system were need some specialized shutdown sequence.
None of them were need power saving.
Please do not generalize your particular system to everything else.
No one needs another self-aware self-configurable software subsystem,
which intended to do the task of the engineers. Especially when this
task takes 15 minutes to code.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-31 16:31 ` Kernel 2.6 size increase Ihar "Philips" Filipau
@ 2003-07-31 16:43 ` Tom Rini
2003-07-31 17:04 ` Ihar "Philips" Filipau
0 siblings, 1 reply; 16+ messages in thread
From: Tom Rini @ 2003-07-31 16:43 UTC (permalink / raw)
To: Ihar Philips Filipau; +Cc: Linux Kernel Mailing List
On Thu, Jul 31, 2003 at 06:31:29PM +0200, Ihar Philips Filipau wrote:
> Tom Rini wrote:
> >
> >Power Management, sysfs plays / will play a role in finding out the order
> >in which devices get powered down. This is important on some types of
> >embedded devices (and arguably important everywhere).
> >
>
> You are contradicting to yourself.
>
> I have participated in creation of two specialized embedded systems,
> and currently going into third one.
> Every system were need some specialized shutdown sequence.
> None of them were need power saving.
Shutdown != sleep. If you want to wake devices up again, you need to do
them in the right order.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-31 16:43 ` Tom Rini
@ 2003-07-31 17:04 ` Ihar "Philips" Filipau
2003-07-31 17:20 ` Tom Rini
0 siblings, 1 reply; 16+ messages in thread
From: Ihar "Philips" Filipau @ 2003-07-31 17:04 UTC (permalink / raw)
To: Tom Rini; +Cc: Linux Kernel Mailing List
Tom Rini wrote:
>
> Shutdown != sleep. If you want to wake devices up again, you need to do
> them in the right order.
>
You didn't get my point.
My appliances do not need sleep/shutdown at all.
Not every embedded system is a handheld ;-)
Shutdown was smth like:
# mount / -o ro; sync; lcd-off; \
dd if=/dev/zero seek=0xBYE of=/dev/port
For a long time it was shell script :-)))
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-31 17:04 ` Ihar "Philips" Filipau
@ 2003-07-31 17:20 ` Tom Rini
2003-07-31 18:02 ` Ihar "Philips" Filipau
0 siblings, 1 reply; 16+ messages in thread
From: Tom Rini @ 2003-07-31 17:20 UTC (permalink / raw)
To: Ihar Philips Filipau; +Cc: Linux Kernel Mailing List
On Thu, Jul 31, 2003 at 07:04:49PM +0200, Ihar Philips Filipau wrote:
> Tom Rini wrote:
> >
> >Shutdown != sleep. If you want to wake devices up again, you need to do
> >them in the right order.
>
> You didn't get my point.
> My appliances do not need sleep/shutdown at all.
> Not every embedded system is a handheld ;-)
That certainly is true, yes. They might want to power things down when
the user isn't there (or maybe they don't, I don't know what you're
making :)). And I did originally say 'some'.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-31 17:20 ` Tom Rini
@ 2003-07-31 18:02 ` Ihar "Philips" Filipau
0 siblings, 0 replies; 16+ messages in thread
From: Ihar "Philips" Filipau @ 2003-07-31 18:02 UTC (permalink / raw)
To: Tom Rini; +Cc: Linux Kernel Mailing List
Tom Rini wrote:
>>
>> You didn't get my point.
>> My appliances do not need sleep/shutdown at all.
>> Not every embedded system is a handheld ;-)
>
>
> That certainly is true, yes. They might want to power things down when
> the user isn't there (or maybe they don't, I don't know what you're
> making :)). And I did originally say 'some'.
>
Can you imagine teapot?
State of your system - on/off. Power saving as done by user herself:
power is consumed only when user want to boil the water ;-)
Two devices I was working on were little bit more complicated and I
had internal UPS to be able to handle power offs/fails gracefuly (like
switching off of LCD + save of the mechanics state).
As for me - I already expressed my point on subject: we should fix
compiler and language (C's inline is definitely not ehough to express
our intentions to compiler). That's the compiler should be optimized to
gain space for performace or gain performance for space.
And sure kernel should be more configurable too.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [uClinux-dev] Kernel 2.6 size increase
@ 2003-07-28 17:13 Nicolas Pitre
2003-07-28 23:02 ` Bernardo Innocenti
0 siblings, 1 reply; 16+ messages in thread
From: Nicolas Pitre @ 2003-07-28 17:13 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Bernardo Innocenti, Willy Tarreau, Christoph Hellwig,
uClinux development list, lkml, Alan Cox
On Fri, 25 Jul 2003, Christoph Hellwig wrote:
> On Thu, Jul 24, 2003 at 10:27:16PM +0200, Bernardo Innocenti wrote:
> > Some of the bigger 2.6 additions cannot be configured out.
> > I wish sysfs and the different I/O schedulers could be removed.
>
> Removing the I/O schedulers is pretty trivial, please come up with a
> patch to make both of them optional and maybe add a trivial noop one.
>
> Removing sysfs should also be pretty trivial but I'm not sure whether
> you really want that.
Being able to remove the block layer entirely, just as for the networking
layer, should be considered too, since none of ramfs, tmpfs, nfs, smbfs,
jffs and jffs2 just to name those ones actually need the block layer to
operate. This is really a big pile of dead code in many embedded setups.
Nicolas
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [uClinux-dev] Kernel 2.6 size increase
2003-07-28 17:13 [uClinux-dev] " Nicolas Pitre
@ 2003-07-28 23:02 ` Bernardo Innocenti
2003-07-29 2:36 ` Miles Bader
0 siblings, 1 reply; 16+ messages in thread
From: Bernardo Innocenti @ 2003-07-28 23:02 UTC (permalink / raw)
To: Nicolas Pitre; +Cc: Willy Tarreau, Christoph Hellwig, lkml, Alan Cox
On Monday 28 July 2003 19:13, Nicolas Pitre wrote:
> > Removing the I/O schedulers is pretty trivial, please come up with a
> > patch to make both of them optional and maybe add a trivial noop one.
> >
> > Removing sysfs should also be pretty trivial but I'm not sure whether
> > you really want that.
>
> Being able to remove the block layer entirely, just as for the networking
> layer, should be considered too, since none of ramfs, tmpfs, nfs, smbfs,
> jffs and jffs2 just to name those ones actually need the block layer to
> operate. This is really a big pile of dead code in many embedded setups.
It's a great idea.
I've read in the Kconfig help that JFFS2 still depends on mtdblock even
though it doesn't use it for I/O. I think I've also seen some promise
that this dependency will eventually be removed...
--
// Bernardo Innocenti - Develer S.r.l., R&D dept.
\X/ http://www.develer.com/
Please don't send Word attachments - http://www.gnu.org/philosophy/no-word-attachments.html
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-28 23:02 ` Bernardo Innocenti
@ 2003-07-29 2:36 ` Miles Bader
0 siblings, 0 replies; 16+ messages in thread
From: Miles Bader @ 2003-07-29 2:36 UTC (permalink / raw)
To: Bernardo Innocenti
Cc: Nicolas Pitre, Willy Tarreau, Christoph Hellwig, lkml, Alan Cox
Bernardo Innocenti <bernie@develer.com> writes:
> > Being able to remove the block layer entirely, just as for the networking
> > layer, should be considered too, since none of ramfs, tmpfs, nfs, smbfs,
> > jffs and jffs2 just to name those ones actually need the block layer to
> > operate. This is really a big pile of dead code in many embedded setups.
>
> It's a great idea.
Yup.
When I've used a debugger to trace through the kernel reading a block on
a system using only romfs, it's utterly amazing how much completely
unnecessary stuff happens.
Of course it's a lot harder to find a clean way to make it optional
than it is to complain about it ... :-)
-Miles
--
I have seen the enemy, and he is us. -- Pogo
^ permalink raw reply [flat|nested] 16+ messages in thread
* Kernel 2.6 size increase
@ 2003-07-23 18:46 Bernardo Innocenti
2003-07-23 19:14 ` Richard B. Johnson
2003-07-23 22:07 ` [uClinux-dev] " Bernardo Innocenti
0 siblings, 2 replies; 16+ messages in thread
From: Bernardo Innocenti @ 2003-07-23 18:46 UTC (permalink / raw)
To: uClinux development list; +Cc: linux-kernel
Hello,
code bloat can be very harmful on embedded targets, but it's
generally inconvenient for any platform. I've measured the
code increase between 2.4.21 and 2.6.0-test1 on a small
kernel configuration for ColdFire:
text data bss dec hex filename
640564 39152 134260 813976 c6b98 linux-2.4.x/linux
845924 51204 78896 976024 ee498 linux-2.5.x/vmlinux
I could provide the exact .config file for both kernels to
anybody interested. They are almost the same: no filesystems
except JFFS2, IPv4 and a bunch of small drivers. I have no
SMP, security, futexes, modules and anything else not
strictly needed to execute processes.
I've made a linker map file and compared the size of single
subsystems. These are the the major contributors to the
size increase:
kernel/ +27KB
mm/ +14KB
fs/ +47KB
drivers/ +35KB
net/ +64KB
I've digged into net/ with nm -S --size-sort. It seems that
the major increase is caused by net/xfrm/. Could this module
be made optional?
In fs/, almost all modules have got 30-40% bigger, therefore
bloat is probably caused by inlines and macros getting more
complex.
Block drivers and MTD have generally become smaller. Character
devices are responsable for most of the size increase in drivers/.
--
// Bernardo Innocenti - Develer S.r.l., R&D dept.
\X/ http://www.develer.com/
Please don't send Word attachments - http://www.gnu.org/philosophy/no-word-attachments.html
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-23 18:46 Bernardo Innocenti
@ 2003-07-23 19:14 ` Richard B. Johnson
2003-07-23 20:07 ` David S. Miller
2003-07-23 22:07 ` [uClinux-dev] " Bernardo Innocenti
1 sibling, 1 reply; 16+ messages in thread
From: Richard B. Johnson @ 2003-07-23 19:14 UTC (permalink / raw)
To: Bernardo Innocenti; +Cc: uClinux development list, linux-kernel
On Wed, 23 Jul 2003, Bernardo Innocenti wrote:
> Hello,
>
> code bloat can be very harmful on embedded targets, but it's
> generally inconvenient for any platform. I've measured the
> code increase between 2.4.21 and 2.6.0-test1 on a small
> kernel configuration for ColdFire:
>
> text data bss dec hex filename
> 640564 39152 134260 813976 c6b98 linux-2.4.x/linux
^^^^^^
> 845924 51204 78896 976024 ee498 linux-2.5.x/vmlinux
[SNIPPED...]
It looks like a lot of data may have been initialized in the
newer kernel, i.e. int barf = 0; or struct vomit = {0,}.
If they just declared the static data, it would end up in
.bss which is allocated at run-time (and zeroed) and is
not in the kernel image.
You might want to check this out. There is 51204 - 39152 = 12,052
more data, but 134260 - 78896 = 55350 less bss.
Cheers,
Dick Johnson
Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips).
Note 96.31% of all statistics are fiction.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-23 19:14 ` Richard B. Johnson
@ 2003-07-23 20:07 ` David S. Miller
2003-07-23 21:47 ` Randy.Dunlap
0 siblings, 1 reply; 16+ messages in thread
From: David S. Miller @ 2003-07-23 20:07 UTC (permalink / raw)
To: root; +Cc: bernie, uclinux-dev, linux-kernel
On Wed, 23 Jul 2003 15:14:22 -0400 (EDT)
"Richard B. Johnson" <root@chaos.analogic.com> wrote:
> On Wed, 23 Jul 2003, Bernardo Innocenti wrote:
> It looks like a lot of data may have been initialized in the
> newer kernel, i.e. int barf = 0; or struct vomit = {0,}.
> If they just declared the static data, it would end up in
> .bss which is allocated at run-time (and zeroed) and is
> not in the kernel image.
GCC 3.3 and later do this automatically.
It's weird, since we killed TONS of explicit zero initializers during
2.5.x, you'd be pressed to find many examples like the one you
mention.
Another thing is that the define_per_cpu() stuff eliminated many huge
[NR_CPUS] arrays. But this probably doesn't apply to his kernel
unless he built is with SMP enabled.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-23 20:07 ` David S. Miller
@ 2003-07-23 21:47 ` Randy.Dunlap
0 siblings, 0 replies; 16+ messages in thread
From: Randy.Dunlap @ 2003-07-23 21:47 UTC (permalink / raw)
To: David S. Miller; +Cc: root, bernie, uclinux-dev, linux-kernel
On Wed, 23 Jul 2003 13:07:12 -0700 "David S. Miller" <davem@redhat.com> wrote:
| On Wed, 23 Jul 2003 15:14:22 -0400 (EDT)
| "Richard B. Johnson" <root@chaos.analogic.com> wrote:
|
| > On Wed, 23 Jul 2003, Bernardo Innocenti wrote:
| > It looks like a lot of data may have been initialized in the
| > newer kernel, i.e. int barf = 0; or struct vomit = {0,}.
| > If they just declared the static data, it would end up in
| > .bss which is allocated at run-time (and zeroed) and is
| > not in the kernel image.
|
| GCC 3.3 and later do this automatically.
|
| It's weird, since we killed TONS of explicit zero initializers during
| 2.5.x, you'd be pressed to find many examples like the one you
| mention.
|
| Another thing is that the define_per_cpu() stuff eliminated many huge
| [NR_CPUS] arrays. But this probably doesn't apply to his kernel
| unless he built is with SMP enabled.
Yes, lots were already killed off, but there are also several
kernel-janitor patches to remove many more static 0 inits.
They can be found at
http://developer.osdl.org/ogasawara/kj-patches/uninit_static/
and I'll be trying to have them merged, although I don't know
how well they will be accepted.
--
~Randy
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [uClinux-dev] Kernel 2.6 size increase
@ 2003-07-23 22:07 ` Bernardo Innocenti
2003-07-23 22:27 ` Willy Tarreau
0 siblings, 1 reply; 16+ messages in thread
From: Bernardo Innocenti @ 2003-07-23 22:07 UTC (permalink / raw)
To: Christoph Hellwig, uClinux development list; +Cc: linux-kernel
On Wednesday 23 July 2003 23:57, Bernardo Innocenti wrote:
> NOTE: I just noticed the 2.4.x kernel was built with -O1 because I
> had symbolic debug enabled. That's not fair: 2.4.20 would probably
> come out even smaller than I reported!
Here come the numbers:
text data bss dec hex filename
640564 39152 134260 813976 c6b98 linux-2.4.x/linux-O1
633028 37952 134260 805240 c4978 linux-2.4.x/linux-Os
So the new comparison base is:
text data bss dec hex filename
633028 37952 134260 805240 c4978 linux-2.4.x/linux-Os
819276 52460 78896 950632 e8168 linux-2.5.x/vmlinux-inline-Os
^^^^^^
2.6 still needs a hard diet... :-/
--
// Bernardo Innocenti - Develer S.r.l., R&D dept.
\X/ http://www.develer.com/
Please don't send Word attachments - http://www.gnu.org/philosophy/no-word-attachments.html
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [uClinux-dev] Kernel 2.6 size increase
2003-07-23 22:07 ` [uClinux-dev] " Bernardo Innocenti
@ 2003-07-23 22:27 ` Willy Tarreau
2003-07-24 20:27 ` Bernardo Innocenti
0 siblings, 1 reply; 16+ messages in thread
From: Willy Tarreau @ 2003-07-23 22:27 UTC (permalink / raw)
To: Bernardo Innocenti
Cc: Christoph Hellwig, uClinux development list, linux-kernel
Hi !
On Thu, Jul 24, 2003 at 12:07:15AM +0200, Bernardo Innocenti wrote:
> text data bss dec hex filename
> 633028 37952 134260 805240 c4978 linux-2.4.x/linux-Os
> 819276 52460 78896 950632 e8168 linux-2.5.x/vmlinux-inline-Os
> ^^^^^^
> 2.6 still needs a hard diet... :-/
I did the same observation a few weeks ago on 2.5.74/gcc-2.95.3. I tried
to track down the responsible, to the point that I completely disabled every
driver, networking option and file-system, just to see, and got about a 550 kB
vmlinux compiled with -Os. 550 kB for nothing :-(
I don't have the config nor the exact numbers right here now, but I can
redo the tests on 2.6.0-test1 if needed.
I was interested in using a very minimal pre-boot kernel with kexec which would
automatically select a valid image among several ones. But 500 kB overhead for
a boot loader quickly refrained me...
Cheers,
Willy
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [uClinux-dev] Kernel 2.6 size increase
2003-07-23 22:27 ` Willy Tarreau
@ 2003-07-24 20:27 ` Bernardo Innocenti
2003-07-29 22:29 ` Tom Rini
0 siblings, 1 reply; 16+ messages in thread
From: Bernardo Innocenti @ 2003-07-24 20:27 UTC (permalink / raw)
To: Willy Tarreau
Cc: Christoph Hellwig, uClinux development list, linux-kernel, Alan Cox
On Thursday 24 July 2003 00:27, Willy Tarreau wrote:
> On Thu, Jul 24, 2003 at 12:07:15AM +0200, Bernardo Innocenti wrote:
> > text data bss dec hex filename
> > 633028 37952 134260 805240 c4978 linux-2.4.x/linux-Os
> > 819276 52460 78896 950632 e8168 linux-2.5.x/vmlinux-inline-Os
> > ^^^^^^
> > 2.6 still needs a hard diet... :-/
>
> I did the same observation a few weeks ago on 2.5.74/gcc-2.95.3. I tried
> to track down the responsible, to the point that I completely disabled
> every driver, networking option and file-system, just to see, and got about
> a 550 kB vmlinux compiled with -Os. 550 kB for nothing :-(
Some of the bigger 2.6 additions cannot be configured out.
I wish sysfs and the different I/O schedulers could be removed.
There are probably many other things mostly useless for embedded
systems that I'm not aware of.
--
// Bernardo Innocenti - Develer S.r.l., R&D dept.
\X/ http://www.develer.com/
Please don't send Word attachments - http://www.gnu.org/philosophy/no-word-attachments.html
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [uClinux-dev] Kernel 2.6 size increase
2003-07-24 20:27 ` Bernardo Innocenti
@ 2003-07-29 22:29 ` Tom Rini
2003-07-29 22:48 ` Alan Cox
0 siblings, 1 reply; 16+ messages in thread
From: Tom Rini @ 2003-07-29 22:29 UTC (permalink / raw)
To: Bernardo Innocenti
Cc: Willy Tarreau, Christoph Hellwig, uClinux development list,
linux-kernel, Alan Cox
On Thu, Jul 24, 2003 at 10:27:16PM +0200, Bernardo Innocenti wrote:
> On Thursday 24 July 2003 00:27, Willy Tarreau wrote:
>
> > On Thu, Jul 24, 2003 at 12:07:15AM +0200, Bernardo Innocenti wrote:
> > > text data bss dec hex filename
> > > 633028 37952 134260 805240 c4978 linux-2.4.x/linux-Os
> > > 819276 52460 78896 950632 e8168 linux-2.5.x/vmlinux-inline-Os
> > > ^^^^^^
> > > 2.6 still needs a hard diet... :-/
> >
> > I did the same observation a few weeks ago on 2.5.74/gcc-2.95.3. I tried
> > to track down the responsible, to the point that I completely disabled
> > every driver, networking option and file-system, just to see, and got about
> > a 550 kB vmlinux compiled with -Os. 550 kB for nothing :-(
>
> Some of the bigger 2.6 additions cannot be configured out.
> I wish sysfs and the different I/O schedulers could be removed.
>
> There are probably many other things mostly useless for embedded
> systems that I'm not aware of.
Well, from Pat's talk at OLS, it seems like sysfs would be an important
part of 'sleep', which is something at least some embedded systems care
about.
... not that 2.6 doesn't need some good pruning options now, but maybe
CONFIG_EMBEDDED isn't the right place to put them all.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [uClinux-dev] Kernel 2.6 size increase
2003-07-29 22:29 ` Tom Rini
@ 2003-07-29 22:48 ` Alan Cox
2003-07-29 23:06 ` Tom Rini
0 siblings, 1 reply; 16+ messages in thread
From: Alan Cox @ 2003-07-29 22:48 UTC (permalink / raw)
To: Tom Rini
Cc: Bernardo Innocenti, Willy Tarreau, Christoph Hellwig,
uClinux development list, Linux Kernel Mailing List
On Maw, 2003-07-29 at 23:29, Tom Rini wrote:
>
> Well, from Pat's talk at OLS, it seems like sysfs would be an important
> part of 'sleep', which is something at least some embedded systems care
> about.
sysfs is relevant for bigger systems but for small embedded stuff the whole
PM layer is fairly "so what". At that level your hardware is tightly defined
and you *know* the power management ordering. Policy becomes critical for
performance and gets done at a very fine grained level - things like waking
up the flash for a read then turning it back off on a timer for example.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [uClinux-dev] Kernel 2.6 size increase
2003-07-29 22:48 ` Alan Cox
@ 2003-07-29 23:06 ` Tom Rini
2003-07-30 2:07 ` Miles Bader
0 siblings, 1 reply; 16+ messages in thread
From: Tom Rini @ 2003-07-29 23:06 UTC (permalink / raw)
To: Alan Cox
Cc: Bernardo Innocenti, Willy Tarreau, Christoph Hellwig,
uClinux development list, Linux Kernel Mailing List
On Tue, Jul 29, 2003 at 11:48:10PM +0100, Alan Cox wrote:
> On Maw, 2003-07-29 at 23:29, Tom Rini wrote:
> >
> > Well, from Pat's talk at OLS, it seems like sysfs would be an important
> > part of 'sleep', which is something at least some embedded systems care
> > about.
>
> sysfs is relevant for bigger systems but for small embedded stuff the whole
> PM layer is fairly "so what". At that level your hardware is tightly defined
> and you *know* the power management ordering. Policy becomes critical for
> performance and gets done at a very fine grained level - things like waking
> up the flash for a read then turning it back off on a timer for example.
And wouldn't it be nice to have one 'policy enforcing tool' or whatever
that you feed it policy_desktop.txt, policy_embedded_in_my_fridge.txt or
policy_enterprise.txt ?
And while you know the ordering for your one board, it's not the same as
that other board there, nor that third board just behind you, and so on.
So getting passed in some sort of tree (or more correctly DAG) and
dealing with it with some more generic code sure sounds nice.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-29 23:06 ` Tom Rini
@ 2003-07-30 2:07 ` Miles Bader
2003-07-30 15:33 ` Tom Rini
0 siblings, 1 reply; 16+ messages in thread
From: Miles Bader @ 2003-07-30 2:07 UTC (permalink / raw)
To: Tom Rini
Cc: Alan Cox, Bernardo Innocenti, Willy Tarreau, Christoph Hellwig,
uClinux development list, Linux Kernel Mailing List
Tom Rini <trini@kernel.crashing.org> writes:
> And wouldn't it be nice to have one 'policy enforcing tool' or whatever
> that you feed it policy_desktop.txt, policy_embedded_in_my_fridge.txt or
> policy_enterprise.txt ?
Sure, but not nice enough to justify requiring more memory or whatever
(of course just that one feature's not going to make much difference,
but in aggregate, they might).
-Miles
--
Run away! Run away!
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-30 2:07 ` Miles Bader
@ 2003-07-30 15:33 ` Tom Rini
2003-07-31 1:49 ` Miles Bader
0 siblings, 1 reply; 16+ messages in thread
From: Tom Rini @ 2003-07-30 15:33 UTC (permalink / raw)
To: Miles Bader
Cc: Alan Cox, Bernardo Innocenti, Willy Tarreau, Christoph Hellwig,
uClinux development list, Linux Kernel Mailing List
On Wed, Jul 30, 2003 at 11:07:24AM +0900, Miles Bader wrote:
> Tom Rini <trini@kernel.crashing.org> writes:
> > And wouldn't it be nice to have one 'policy enforcing tool' or whatever
> > that you feed it policy_desktop.txt, policy_embedded_in_my_fridge.txt or
> > policy_enterprise.txt ?
>
> Sure, but not nice enough to justify requiring more memory or whatever
> (of course just that one feature's not going to make much difference,
> but in aggregate, they might).
Well, that sort-of depends on which 'embedded' board you're talking
about really. And the trade-off between the work needed for a hacked-up
1 off, the space that could be saved by doing this, and the space that
could be saved elsewhere. Perhaps on the embedded_in_my_fridge machine
it might make sense, but not ever embedded device is quite so tiny and
strapped for space.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-30 15:33 ` Tom Rini
@ 2003-07-31 1:49 ` Miles Bader
2003-07-31 4:17 ` Tom Rini
0 siblings, 1 reply; 16+ messages in thread
From: Miles Bader @ 2003-07-31 1:49 UTC (permalink / raw)
To: Tom Rini
Cc: Alan Cox, Bernardo Innocenti, Willy Tarreau, Christoph Hellwig,
uClinux development list, Linux Kernel Mailing List
Tom Rini <trini@kernel.crashing.org> writes:
> > but not nice enough to justify requiring more memory or whatever (of
> > course just that one feature's not going to make much difference,
> > but in aggregate, they might).
>
> Well, that sort-of depends on which 'embedded' board you're talking
> about really.
The point was that in _some_ embedded systems, the space-savings is
wanted, and so a useful thing for linux to support.
-Miles
--
Suburbia: where they tear out the trees and then name streets after them.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-31 1:49 ` Miles Bader
@ 2003-07-31 4:17 ` Tom Rini
2003-07-31 5:03 ` Miles Bader
0 siblings, 1 reply; 16+ messages in thread
From: Tom Rini @ 2003-07-31 4:17 UTC (permalink / raw)
To: Miles Bader
Cc: Alan Cox, Bernardo Innocenti, Willy Tarreau, Christoph Hellwig,
uClinux development list, Linux Kernel Mailing List
On Thu, Jul 31, 2003 at 10:49:06AM +0900, Miles Bader wrote:
> Tom Rini <trini@kernel.crashing.org> writes:
> > > but not nice enough to justify requiring more memory or whatever (of
> > > course just that one feature's not going to make much difference,
> > > but in aggregate, they might).
> >
> > Well, that sort-of depends on which 'embedded' board you're talking
> > about really.
>
> The point was that in _some_ embedded systems, the space-savings is
> wanted, and so a useful thing for linux to support.
To what end? One of the things we (== PPC folks) at OLS was that, wow,
doing PM as some sort of one-off sucks, and if at all possible we want
to get device information (and pm dependancies) passed in so we can tell
sysfs and get any shared driver done right for free, among other
reasons.
As has been pointed out, there's things like the block layer that aren't
needed if you have just a subset of common embedded-device filesystems and
some network stuff seems to have creeped back in. All I'm trying to say
is that before you go too far down the CONFIG_SYSFS route, investigate the
others first as there's a fair chance of saving even more.
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-31 4:17 ` Tom Rini
@ 2003-07-31 5:03 ` Miles Bader
2003-07-31 15:24 ` Tom Rini
0 siblings, 1 reply; 16+ messages in thread
From: Miles Bader @ 2003-07-31 5:03 UTC (permalink / raw)
To: Tom Rini
Cc: Alan Cox, Bernardo Innocenti, Willy Tarreau, Christoph Hellwig,
uClinux development list, Linux Kernel Mailing List
Tom Rini <trini@kernel.crashing.org> writes:
> > The point was that in _some_ embedded systems, the space-savings is
> > wanted, and so a useful thing for linux to support.
>
> As has been pointed out, there's things like the block layer that aren't
> needed if you have just a subset of common embedded-device filesystems and
> some network stuff seems to have creeped back in. All I'm trying to say
> is that before you go too far down the CONFIG_SYSFS route, investigate the
> others first as there's a fair chance of saving even more.
I'm not really trying to defend this particular config option, just
saying that the attitude of `why bother trying to cut down, it's more
featureful to include everything!' is not always valid.
You may very well be right that other subsystems offer better
gain/pain, and I'm all for attacking the low-hanging-fruit first.
> To what end? One of the things we (== PPC folks) at OLS was that, wow,
> doing PM as some sort of one-off sucks, and if at all possible we want
> to get device information (and pm dependancies) passed in so we can tell
> sysfs and get any shared driver done right for free, among other
> reasons.
[What's PM? Power Management? What does that have to do with anything?]
-Miles
--
Would you like fries with that?
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Kernel 2.6 size increase
2003-07-31 5:03 ` Miles Bader
@ 2003-07-31 15:24 ` Tom Rini
0 siblings, 0 replies; 16+ messages in thread
From: Tom Rini @ 2003-07-31 15:24 UTC (permalink / raw)
To: Miles Bader
Cc: Alan Cox, Bernardo Innocenti, Willy Tarreau, Christoph Hellwig,
uClinux development list, Linux Kernel Mailing List
On Thu, Jul 31, 2003 at 02:03:34PM +0900, Miles Bader wrote:
> Tom Rini <trini@kernel.crashing.org> writes:
> > > The point was that in _some_ embedded systems, the space-savings is
> > > wanted, and so a useful thing for linux to support.
> >
> > As has been pointed out, there's things like the block layer that aren't
> > needed if you have just a subset of common embedded-device filesystems and
> > some network stuff seems to have creeped back in. All I'm trying to say
> > is that before you go too far down the CONFIG_SYSFS route, investigate the
> > others first as there's a fair chance of saving even more.
>
> I'm not really trying to defend this particular config option, just
> saying that the attitude of `why bother trying to cut down, it's more
> featureful to include everything!' is not always valid.
I hate email sometimes. My attitude is "some things you really can't
cut out". I really am all for trying to cut things out, it's just that
some things are tied in rather well (like sysfs and root device as
opposed to the static table before).
> You may very well be right that other subsystems offer better
> gain/pain, and I'm all for attacking the low-hanging-fruit first.
>
> > To what end? One of the things we (== PPC folks) at OLS was that, wow,
> > doing PM as some sort of one-off sucks, and if at all possible we want
> > to get device information (and pm dependancies) passed in so we can tell
> > sysfs and get any shared driver done right for free, among other
> > reasons.
>
> [What's PM? Power Management? What does that have to do with anything?]
Power Management, sysfs plays / will play a role in finding out the order
in which devices get powered down. This is important on some types of
embedded devices (and arguably important everywhere).
--
Tom Rini
http://gate.crashing.org/~trini/
^ permalink raw reply [flat|nested] 16+ messages in thread
end of thread, other threads:[~2003-07-31 18:01 UTC | newest]
Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
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2003-07-31 16:31 ` Kernel 2.6 size increase Ihar "Philips" Filipau
2003-07-31 16:43 ` Tom Rini
2003-07-31 17:04 ` Ihar "Philips" Filipau
2003-07-31 17:20 ` Tom Rini
2003-07-31 18:02 ` Ihar "Philips" Filipau
2003-07-28 17:13 [uClinux-dev] " Nicolas Pitre
2003-07-28 23:02 ` Bernardo Innocenti
2003-07-29 2:36 ` Miles Bader
-- strict thread matches above, loose matches on Subject: below --
2003-07-23 18:46 Bernardo Innocenti
2003-07-23 19:14 ` Richard B. Johnson
2003-07-23 20:07 ` David S. Miller
2003-07-23 21:47 ` Randy.Dunlap
2003-07-23 22:07 ` [uClinux-dev] " Bernardo Innocenti
2003-07-23 22:27 ` Willy Tarreau
2003-07-24 20:27 ` Bernardo Innocenti
2003-07-29 22:29 ` Tom Rini
2003-07-29 22:48 ` Alan Cox
2003-07-29 23:06 ` Tom Rini
2003-07-30 2:07 ` Miles Bader
2003-07-30 15:33 ` Tom Rini
2003-07-31 1:49 ` Miles Bader
2003-07-31 4:17 ` Tom Rini
2003-07-31 5:03 ` Miles Bader
2003-07-31 15:24 ` Tom Rini
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