On 25 February 2010 19:20, Michal Suchanek <[email protected]> wrote: > On 25 February 2010 04:30, William Leslie <[email protected]> > wrote: >> Letting the application developer decide the paging strategy makes >> memory pressure a more useful covert channel, though. It could be less >> of a big deal now that applications are moving to safe languages, >> indeed, it may be reasonable to allow application specific paging >> algorithms working in an environment where side effects from the >> frequency of paging are provably impossible. > > You can't force the application to run in a safe language, can you?
I meant the pager, but I was wrong anyway. As long as the pager implements the eviction strategy, and not the process of populating the pages, this is safe. But if you want to, for example, use memory as a cache but generate its contents on page in, or implement an application or language specific serialisation and persistence strategy, that is a different kettle of fish. On 26 February 2010 04:35, Jonathan S. Shapiro <[email protected]> wrote: > On Wed, Feb 24, 2010 at 7:30 PM, William Leslie > <[email protected]> wrote: >> >> Letting the application developer decide the paging strategy makes >> memory pressure a more useful covert channel, though. > > > Not correct. What creates the channel is allowing the memory pressure of one > application to have impact on the paging behavior of a second application. > If this is sufficiently isolated, there is no further hazard from allowing > the application to make its own eviction choice. Sure, but a fixed allocation could be prohibitively expensive as a default in a general purpose system. You want to use the ram you have. Giving each user, let alone each eg browser process their own dedicated spacebank does not seem reasonable, and neither does requiring the user to set allocations. William Leslie ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ CapROS-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/capros-devel
