On Fri, Sep 19, 2008 at 5:54 PM, <[EMAIL PROTECTED]> wrote: > On Fri, Sep 19, 2008 at 05:29:20PM +0530, nidhi mittal wrote: > > as if linear address is of 32 bits then total linear address space of 4GB > is > > mapped to physical address space. > > then i wanted to ask > > Is this address space is split among all processes ? > > OR > > each process gets its independent full 4GB linear address space. ? > Each process gehts its independent 4GB linear address space. > The mapping work is done by the MMU. > > HTH > -- > Patrick Kirsch > http://spielux.de | Open Source Spiele, Bewertungen, Auftragsentwicklung > > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to [EMAIL PROTECTED] > Please read the FAQ at http://kernelnewbies.org/FAQ > > The linear address space of a process is divided into two parts Linear addresses from 0x00000000 to 0xbfffffff can be addressed when the process runs in either User or Kernel Mode. Linear addresses from 0xc0000000 to0xffffffff can be addressed only when the process runs in Kernel Mode.
When a process runs in User Mode, it issues linear addresses smaller than 0xc0000000 when it runs in Kernel Mode, it is executing kernel code and the linear addresses issued are greater than or equal to 0xc0000000. In some cases, however, the kernel must access the User Mode linear address space to retrieve or store data. -karunakar
