AnsweredAssumed Answered

i.mx6 solo reserved memory too high

Question asked by ZC Tee on Jun 11, 2015
Latest reply on Nov 1, 2015 by ZC Tee

Hi all,

I am trying to migrate my kernel from 3.0.15 to 3.0.101.

Upon fresh build of 3.0.101 with default imx6_defconfig, i am able to boot up the board.

My board is mounted with 512MB of RAM (2 x 16bit DDRRAM).

 

Upon boot up, i see that the memory available is only 246348k, where the rest is placed in reserved section, as kernel log below:

     PID hash table entries: 1024 (order: 0, 4096 bytes)

     Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)

     Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)

     Memory: 256MB = 256MB total

     Memory: 246348k/246348k available, 277940k reserved, 0K highmem

     Virtual kernel memory layout:

         vector  : 0xffff0000 - 0xffff1000   (   4 kB)

         fixmap  : 0xfff00000 - 0xfffe0000   ( 896 kB)

         DMA     : 0xf4600000 - 0xffe00000   ( 184 MB)

         vmalloc : 0xa0800000 - 0xf2000000   (1304 MB)

         lowmem  : 0x80000000 - 0xa0000000   ( 512 MB)

         pkmap   : 0x7fe00000 - 0x80000000   (   2 MB)

         modules : 0x7f000000 - 0x7fe00000   (  14 MB)

           .init : 0x80008000 - 0x8003c000   ( 208 kB)

           .text : 0x8003c000 - 0x80a99a5c   (10615 kB)

           .data : 0x80a9a000 - 0x80afe760   ( 402 kB)

            .bss : 0x80afe784 - 0x80b2c24c   ( 183 kB)

     SLUB: Genslabs=13, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1

From the log above, the memory is at 256MB only, but the lowmem is able to detect 512MB. Is it normal that the reserved memory is that much (277940k)?

 

In my previous kernel of 3.0.15, i am able to get 513264k memory available with only 11024k reserved memory. What makes the different? or is there anywhere in kernel that i can change the allocation of the reserved memory?

 

Thank you.

 

Regards,

ZC

Outcomes