lkml.org 
[lkml]   [2007]   [Jun]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH, RFD]: Unbreak no-mmu mmap
Mike Frysinger wrote:
> On 6/9/07, Matt Mackall <mpm@selenic.com> wrote:
>> On Fri, Jun 08, 2007 at 03:53:49PM +0200, Bernd Schmidt wrote:
>> > 2. It is no longer possible to get blocks smaller than a page through
>> > mmap. This behaviour was used by simplemalloc, which is an insane
>> > way of implementing malloc on nommu systems and hopefully not used
>> > by anyone anymore.
>>
>> That's worrisome. Breaking existing apps/libraries seems like a bad
>> idea.
>
> it isnt breaking anything ... simplemalloc() will continue to execute
> in newer kernels

While that's true, it'll have an even bigger memory overhead than it
already does (simplemalloc, by trapping into the kernel and creating
vm_area/vm_list structures for every malloc call, has huge overheads in
both time and space).
I've posted this as an RFD to get a feeling for whether we can change
behaviour here - I do expect that nommu embedded systems are less
constrained by backwards compatibility considerations, but I'd like to
hear from other embedded users whether this is a change they'd welcome.


Bernd
--
This footer brought to you by insane German lawmakers.
Analog Devices GmbH Wilhelm-Wagenfeld-Str. 6 80807 Muenchen
Sitz der Gesellschaft Muenchen, Registergericht Muenchen HRB 40368
Geschaeftsfuehrer Thomas Wessel, William A. Martin, Margaret Seif
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-06-12 01:07    [W:0.087 / U:1.736 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site