Shared memory

[akshayFarcry]

Are there features that the kernel provides for user processes to start sharing their memories during runtime that can avoid a kernel copy for transfer of the said shared memory?

Ex:
p1
{
buf buf1;


if(some_conditon)
{
handle=share(buf);
}
}


p2
{
buf buf2;
buf2=shared(handle);
}

[Rubberman]

Read the man page shm_overview to get an overview of memory sharing in Linux. Basically, it maps the shared memory segment into the process virtual memory space. Once that is done, as far as I know writing to that memory is direct and doesn't require kernel access.