mmap fail with error 22

[Prasad Bc]

Hi All,

   I need help with the mmap failure with my linux kernel version 3.6.4

   here is the following code 
    if ((fd = open ("/dev/mem", O_RDWR)) < 0)
    {
        return ((uint32_t) -1);
    }

    mem_virt_addr = mmap (NULL,
                              mem_size,
                              PROT_READ | PROT_WRITE,
                              MAP_SHARED | MAP_NORESERVE,
                              fd,
                              0);
    close (fd);

    if (mem_virt_addr == NULL)
    {
        error_msg ("memory count not be mapped (%d).", errno);
        return ((uint32_t) -1);
    }

From the above code if I specify mem_size as 1MB (1024*1024) code works fine. If I increase the size >1MB then I get error number 22 which is "EINVAL". Can any one help me on how to get rid of this error. I need a memory size of 64MB.

I have unset the .config file for CONFIG_STRICT_DEVMEM and built the kernel.

Regards,

-Prasad

[Anil Kumar Pugalia]

Hi Prasad,
    What are you trying to do, by directly mmaping such big chunk of memory?

Regards
Anil

Passion: http://sysplay.in (Playing with Systems)

Prasad Bc said the following on Monday 09 June 2014 04:59 PM:

--
You received this message because you are subscribed to the Google Groups "SysPlay's Inside Linux" group.
To unsubscribe from this group and stop receiving emails from it, send an email to inside_linux...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.