2009-03-06 04:43:11 Regarding defragmentation in BF533
Hari Prasad (INDIA)
Message: 70526
Hi,
I need to malloc a memory chunk of 7MB in my app but the max size I can allocate is 2MB coz most of the free memory is fragmented. Is there any mechanism available which will defragment all the fragmented memory so that I can dynamically allocate a 7MB memory chunk?
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2009-03-06 04:49:25 Re: Regarding defragmentation in BF533
Mike Frysinger (UNITED STATES)
Message: 70528
the mechanism is called "virtual memory". since the Blackfin lacks a MMU, it cannot defragment things.
if you need large chunks, allocate them once at boot and never free them.
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2009-03-06 04:54:57 Regarding defragmentation in BF533
Michael Hennerich (GERMANY)
Message: 70529 > Is there any mechanism available which will defragment all the fragmented memory
No
But check this out:
docs.blackfin.uclinux.org/doku.php?id=linux-kernel:memory_allocation#silly_nommu_memory_tricks
Reserve your 7MB block upfront.
-Michael
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2009-03-06 07:46:15 Re: Regarding defragmentation in BF533
Hari Prasad (INDIA)
Message: 70531
Hi,
Could you please help me how to interpret this error message:
DMA free:15384kB min:1008kB low:1260kB high:1512kB active:5804kB inactive:5924kB present:63880kB pages_scanned:12342 all
_unreclaimable? no
lowmem_reserve[]: 0 0
DMA: 64*4kB 53*8kB 37*16kB 9*32kB 6*64kB 13*128kB 20*256kB 13*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB 0*32768kB = 15384kB
I got this error when I was trying to create a memory pool of 512KB chunks.
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2009-03-06 13:30:30 Re: Regarding defragmentation in BF533
Mike Frysinger (UNITED STATES)
Message: 70537
it's telling you you're out of memory and then it shows you what pieces are free