Re: [RFC] [PATCH] kmem_alloc (generic wrapper for kmalloc and vmalloc)

[Geert Uytterhoeven]

On Wed, 10 Nov 2004, Carl-Daniel Hailfinger wrote:
> Robert Love schrieb:
> > On Wed, 2004-11-10 at 06:19 +0100, Carl-Daniel Hailfinger wrote:
> >>it seems there is a bunch of drivers which want to allocate memory as
> >>efficiently as possible in a wide range of allocation sizes. XFS and
> >>NTFS seem to be examples. Implement a generic wrapper to reduce code
> >>duplication.
> >>Functions have the my_ prefixes to avoid name clash with XFS.
> > 
> > 
> > No, no, no.  A good patch would be fixing places where you see this.
> > 
> > Code needs to conscientiously decide to use vmalloc over kmalloc.  The
> > behavior is different and the choice needs to be explicit.
> 
> Yes, but what do you suggest for the following problem:
> alloc(max_loop*sizeof(struct loop_device))
> 
> where sizeof(struct loop_device)==304 and 1<=max_loop<=16384
> 
> For the smallest allocation (304 bytes) vmalloc is clearly wasteful
> and for the largest allocation (~ 5 MBytes) kmalloc doesn't work.

Try vmalloc() if kmalloc() fails?

BTW, is there a simple and portable way to distinguish between memory allocated
using kmalloc() and vmalloc(), or should the called remember the allocation
method?

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds
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