Re: [PATCH 2/2] x86, boot: Optimize the elf header handling.

From: H. Peter Anvin
Date: Sun Jul 01 2012 - 14:37:26 EST


On 07/01/2012 11:25 AM, Eric W. Biederman wrote:
>
> Well I see what is going on now.
>
> In the vmlinux the paddrs and the poffsests stop tracking when they
> come to the percpu PT_LOAD segment.
>
> It looks like we give the percpu segment a 4K alignment in memory
> and a 2M alignment in the file.
>
> It looks like something is causing ld to compute an unfortunate physical
> load address for the percpu section.
>
> At first glace I would say that is a bug. Either we need the alignment
> or we don't. But if we need the alignment we certainly need it to
> be respected for the real memory locations of the init symbols..
>

If we don't need it, I think we can use -z max-page-size=4096, but we
use the PMD alignment for percpu on x86-64; Tejun, does that apply to
the .data..percpu section in the executable as well?

-hpa

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/