Subject: Re: Add a MAP_ALIGNED flag for mmap(2).
To: Jason R Thorpe <email@example.com>
From: Matt Thomas <firstname.lastname@example.org>
Date: 02/28/2003 21:16:46
At 08:13 PM 2/28/2003, Jason R Thorpe wrote:
>On Fri, Feb 28, 2003 at 06:01:47PM -0800, Matt Thomas wrote:
> > Currently, ld.elf_so doesn't honor the alignment specified in a
> > ELF file's psections. This is due to the lack of ability to request
> > an aligned block of addresses from mmap(2). I propose we add a
> > MAP_ALIGNED flag which would mean that the addr argument to mmap(2)
> > would be the required alignment of the block. Supplying both
> > MAP_ALIGNED|MAP_FIXED would cause an error EINVAL to be returned.
> > Any thought on this proposal?
>Sounds good. I'm a little concerned that it means you can't pass a
>"please map it in this general neighborhood of the address space", but
>I definitely want the ability to specify alignment.
Define general area. 1MB? 16MB? 128MB?
>One question -- what happens if mmap can't satisfy the alignment
>contraint? Is it just a hint or a strict requirement?
I'd say it's a strict requirement like MAP_FIXED it.
Matt Thomas Internet: email@example.com
3am Software Foundry WWW URL: http://www.3am-software.com/bio/matt/
Cupertino, CA Disclaimer: I avow all knowledge of this message