Re: 2.6.21-mm1

Andrew Morton
2007-05-06T20:55:38Z

On Sun, 6 May 2007 22:44:29 +0200 Sam Ravnborg <sam@ravnborg.org> wrote:

> On Sun, May 06, 2007 at 08:33:48AM +0400, Dan Kruchinin wrote:
> > >
> > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21/2.6.21-mm1/
> >
> > I have the following message after kernel compilation:
> >
> > ---
> > ...
> > WARNING: init/built-in.o - Section mismatch: reference to .init.text:
> > from .text between 'rest_init' (at offset 0x11e) and 'try_name'
>
> Covered in another mail.
>
> > ...
> > ...
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x20)
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x24)
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x28)
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x2c)
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x30)
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x34)
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x38)
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x3c)
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x40)
> > WARNING: drivers/dma/async_tx.o - Section mismatch: reference to
> > .init.data: from .data after 'channel_table' (at offset 0x44)
>
> We have following code:
> /* guarantee that calls that happen before init will not find a channel */
> static struct chan_ref_percpu __initdata null_chan_ref[NR_CPUS];
>
> static struct chan_ref_percpu *channel_table[] = {
> DMA_TX_ARRAY_INIT(null_chan_ref)
> };
>
> The DMA_TX_ARRAY_INIT is some macro obscufation that serves no
> real use and just hide a few assignements.
> What happens here is that we assign channel_table a value
> that are used as cover-up until the real assignment happens
> in the init function.
> So the only real way to fix this seems to remove the otherwise correct
> __initdata mark on null_chan_ref.
> Thats one pointer wasted pr. cpu (in total NR_CPUS).
>

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