On Thu, Jun 19, 2014 at 8:51 AM, sandeep kumar <coolsandyforyou@xxxxxxxxx> wrote: > Hi All > > i was going through mm initialization code, and saw paging_init() > implementation. > it has a function map_lowmem(). > > I was wondering why do we need page table entries for lowmem ?? > I hope you understand how MMU and virtual memory works. > because all the pages in lowmem can be addressed by kernel logical address > and differ only an offset from the physical address. Why cant we simply add > that offset to the virtual(logical) address and get the job done. Why waste > some memory for creating PTEs for them? Let's forget about lowmem or high mem. See the role of MMU and you'll understand why it's needed. > > can any one clarify? > > > -- > With regards, > Sandeep Kumar Anantapalli, > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > -- ---P.K.S _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
