On Sat, Apr 6, 2013 at 9:23 PM, Terry Hsu <terry.sh...@gmail.com> wrote: > Is there any available resource that explains how user-mode-linux maps the > pages of a task in UML to the host kernel?
The code...? ;) UML receives a SIGEGV on the host side if a page is not mapped. The SIGEGV handler then installs the mapping using mmap(). > In my UML, I modified a task's page table when forking it. Then I ran into a > situation where the page fault happens over and over again for the same > address in the forked task. I use gdb debugger and find out that when the > page fault happens for the first time, the kernel calls do_wp_page() to > fault in the page and marks the page present. This should prevent the next > page fault for the same address from happening again. I checked the PTE in > UML, they are marked as present so is it possible that the page is not being > allocated properly on the host kernel so that the page fault keeps happening > for the same address even though UML thinks the page is present. > > Any suggestions? If the same fault happens over and over UML (on the host side) seems unable to fix the fault. Check the return values of mmap().... Thanks, //richard ------------------------------------------------------------------------------ Minimize network downtime and maximize team effectiveness. Reduce network management and security costs.Learn how to hire the most talented Cisco Certified professionals. Visit the Employer Resources Portal http://www.cisco.com/web/learning/employer_resources/index.html _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
