On 7/18/07, yogesh tillu <[EMAIL PROTECTED]> wrote:
Yeah, thats right. The buffer is filled but not flushed. After the fork, the entire address space (and hence the buffer) gets replicated * But I think currently copy on write approach is used for the *implementation of the fork .So entire address space will not get *replicated {previously clone approach was used , so in that *whole address space gets replicated } *
Copy-on-write (COW) is a method of replication of address spaces. Its a bit hard to explain on mail, but the basic concept is this - It is not necessary to actually copy the pages in memory until the data in the two processes becomes different. Till then the OS maintains page tables such that the same page is used until one of the processes modifies the contents of that page. When that happens, the page is first copied and then written. Obviously, it is no longer shared after that. So it doesnt matter whether whether the OS uses COW or not. When seen from userland, the address space is replicated. Hope that answers your question. For details, refer to some book on OS theory. -aditya -- ______________________________________________________________________ Pune GNU/Linux Users Group Mailing List: (plug-mail@plug.org.in) List Information: http://plug.org.in/cgi-bin/mailman/listinfo/plug-mail Send 'help' to [EMAIL PROTECTED] for mailing instructions.