Messages in this thread | | | Date | Wed, 9 Feb 2011 03:41:44 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] Remove CONFIG_PM altogether, enable power management all the time |
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* Tim Bird <tbird20d@gmail.com> wrote:
> On Tue, Feb 8, 2011 at 4:21 AM, Ingo Molnar <mingo@elte.hu> wrote: > > > Rafael, could you do a defconfig-ish x86 build with and without CONFIG_PM, and > > post the 'size vmlinux' comparison - so that we can see the size difference? We > > make some things CONFIG_EXPERT configurable just to enable folks who *really* > > want to cut down on kernel size to configure it out. > > I'm one of those people who *really* wants to cut down the kernel size. I've > recently worked on a product where the kernel RAM budget is ~1M.
Did that kernel have CONFIG_PM disabled?
> > Note that those usecases, even if they want a super-small kernel, might not care > > about PM at all while they care about size: small boot kernels in ROMs, or > > simple devices where CPU-idling implies deep low power mode, etc. > > So the vmlinux size comparisons would be needed really. If it's 5k nobody will > care. I care about 5K. (But honestly, I don't actively hunt stuff less than 10K > in size, because there's too many of them to chase, currently).
The numbers that Frank Rowand sent show 40K+:
| | For 2.6.38-rc4, x86_64, CONFIG_NR_CPUS=4: | | size vmlinux | text data bss dec hex filename | | 6553910 3555020 9994240 20103170 132c002 vmlinux with CONFIG_PM | 6512652 3553116 9994240 20060008 1321768 vmlinux without CONFIG_PM | | 41258 1904 0 43162 delta |
Thanks,
Ingo
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