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Message-ID: <4E932897.2060907@in.ibm.com>
Date: Mon, 10 Oct 2011 22:47:11 +0530
From: Suzuki Poulose <suzuki@in.ibm.com>
MIME-Version: 1.0
To: Scott Wood <scottwood@freescale.com>
Subject: Re: [PATCH 1/3] [powerpc32] Process dynamic relocations for kernel
References: <20111010094627.16589.52367.stgit@suzukikp.in.ibm.com>
 <20111010095432.16589.32935.stgit@suzukikp.in.ibm.com>
 <4E930BFA.5030701@freescale.com>
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Cc: Michal Simek <monstr@monstr.eu>, tmarri@apm.com,
 Mahesh Jagannath Salgaonkar <mahesh@linux.vnet.ibm.com>,
 Dave Hansen <dave@linux.vnet.ibm.com>, David Laight <David.Laight@ACULAB.COM>,
 Paul Mackerras <paulus@samba.org>, Alan Modra <amodra@au1.ibm.com>,
 linux ppc dev <linuxppc-dev@lists.ozlabs.org>, Vivek Goyal <vgoyal@redhat.com>
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On 10/10/11 20:45, Scott Wood wrote:
> On 10/10/2011 04:55 AM, Suzuki K. Poulose wrote:
>> The following patch implements the dynamic relocation processing for
>> PPC32 kernel. relocate() accepts the target virtual address and relocates
>>   the kernel image to the same.
>
> How much overhead is involved in a true relocatable kernel?  Is it worth
> preserving the old "relocatable" booke behavior under a different name?

There are '75782' on an ebony kernel with minimal config. So thats a pretty big
number for small embedded chips. I guess, preserving the 'old relocatable' (page
aligned approach) would be a good idea for the architectures which can afford it.
e.g, places where TLB size is 64M or less.

Thanks
Suzuki