ucc_geth DPRAM alloc error, 2.6.22-rc3

Rune Torgersen runet at innovsys.com
Fri Jun 15 08:46:00 EST 2007


> -----Original Message-----
> From: Joakim Tjernlund
> Sent: Thursday, June 14, 2007 2:18 AM

> some comments:
> 
> With these aligments, won't you waste alot of MURAM?
> 
> Looking at the 2 first allocs:
>   MURAM alloc, start:1400, size:200(512), align:8(8)
>   MURAM alloc, start:1608, size:208(520), align:8(8)
> shouldn't the second alloc have 0x1600 as start address?

I've noticed (on a internal project that uses a LOT of DPRAM on a 82xx,
uses same allocator), that the current allignment stuff allocates bytes
requested + allignment and never frees the unused space.

So if you want 8 bytes with 64 bytes allignment, the allocator
allocatesd (8+64) 72 bytes. It should then return the unused 64 bytes at
the beginning and end to the pool, but doesn't.

I have an internal version of the allocator that does it correct (for us
atleast), and also does a best fit instead of first fit.

If anybody is interested, I can post it. Mine is the rheap from arch/ppc
not arch/powerpc



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