Find the answer to your Linux question:
Results 1 to 2 of 2
Hi Everybody, I am working on montavista linux, on broadcom chipset, mips processor...having 32Mb RAM..out of which top 2Mb has been given for DMA access..remaining 30Mb should be available. But ...
Enjoy an ad free experience by logging in. Not a member yet? Register.
  1. #1
    Just Joined!
    Join Date
    Oct 2005
    Posts
    1

    Reducing the reserved memory for kernel


    Hi Everybody,
    I am working on montavista linux, on broadcom chipset, mips processor...having 32Mb RAM..out of which top 2Mb has been given for DMA access..remaining 30Mb should be available. But in cat /proc/meminfo it only shows 26Mb free, in dmesg..it shows that 4.7Mb is reserved for kernel. That is far too much that i expect as I have heard it ahuld not be more than 2-3% of total memory. How to reduce it? I am having busybox utilities.
    here is the output:
    cat /proc/meminfo

    total: used: free: shared: buffers: cached:
    Mem: 27181056 7303168 19877888 0 53248 5435392
    Swap: 0 0 0
    MemTotal: 26544 kB
    MemFree: 19412 kB
    MemShared: 0 kB
    Buffers: 52 kB
    Cached: 5308 kB
    SwapCached: 0 kB
    Active: 720 kB
    Inactive: 4984 kB
    HighTotal: 0 kB
    HighFree: 0 kB
    LowTotal: 26544 kB
    LowFree: 19412 kB
    SwapTotal: 0 kB
    SwapFree: 0 kB
    Committed_AS: 1056 kB
    VmallocTotal: 1048560 kB
    VmallocUsed: 448 kB
    VmallocChunk: 1048112 kB



    dmesg|grep [Mm]em


    Setting memory region to 0x2000000
    Environment [0] : <memsize=32>
    5200 mem=30M ramdisk_size=8192 nfsroot=10.240.4.61:/home/canoop/target
    U-BOOT Environment: bootargs = root=/dev/ram console=ttyS0,115200 mem=30M
    memory: 02000000 @ 00000000 (usable)
    memory: 01e00000 @ 00000000 (usable)
    Kernel command line: yroot=/dev/ra console=ttyS0,115200 mem=30M
    Memory: 25996k/30720k available (1474k kernel code, 4724k reserved, 92k data, 80k init, 0k
    highmem)
    Disabling the Out Of Memory Killer
    Freeing initrd memory: 466k freed
    Freeing unused kernel memory: 80k freed




    Theres also another instance where dmesg doent show reserved space for kernel. So, I am wondering without this reserved space, it can work.....I have to reduce the memory by 3Mb. Any suggestions?

    Can I reduce the buffer cache, right now its almost 5.4Mb..I think that I can reduce by 1 Mb....any idea, how much effect will it have over perormance?

    /*What my suspicion is: Does Montavista linux has some limitation abt the minimum reserved space?*/




    Thanks,
    sudip

  2. #2
    Just Joined!
    Join Date
    Jun 2006
    Posts
    5

    mobilinux

    first of all you shouls say me how can I find Montavista linux Sorce code?

    I realy need it .

    thanks.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •