gaurav wrote:
thats rite but wen all processes have different address spaces so cant we
say that each process have duplicated copy of same data?
Of course all of the processes have a copy of the same data. The data
is copied, from the page cache, into a buffer which is contained in the
address space of the process. This buffer is allocated by the process,
not by the operating system.
The operating system maintains a single copy of the data in its page
cache, no matter how many processes are accessing the data and if it
has enough free memory to do so.
ps
