Messages in this thread | | | Date | Tue, 12 Jun 2007 01:04:01 +0200 | From | Bernd Schmidt <> | Subject | Re: [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/
| |