hi , I had a problem with remapping too. Could I see your code? here is my code, that some times on AMD64 runs wrong : http://pastebin.com/m78da0b37
And now I solved the problem with remapping by using /dev/mem device. It has mmap syscal. And it seems to be working without problem. Alexej < 2009/3/13 Pekka Nikander <[email protected]> > As a part of a research project, I'm trying to build publish/subscribe > shared memory semantics where the idea is to first map an vm_object as > read/write to a publisher's memory space, and then a COW shadow of that > later to the subscriber processes' memory space. > > I've got to the point where the code works most of the time, but at certain > scenarios (which are hard to classify and seem slightly random) the mapping > goes wrong, and either the subscriber process has no physical mapping at the > supposed address or there appears some random page. To me it appears as if > the vm_object, vm_map etc data structures are OK, but somehow the pmaps > don't get right. I'm currently using 7.1 RELEASE on amd64, but I'm planning > to try the same on -CURRENT as soon as I get it properly ported. I even > tried calling pmap_enter_object explicitly before returning to the user > space, but it doesn't seem to help. > > Another thing is that there may be some bugs related OBJ_ONEMAPPING. We > need to explicitly clear it at places, and sometimes artificially bump up > the vm_object reference count to avoid code related to ONEMAPPING from > trashing the object's mappings. Is this a known issue? > > Any advice? > > --Pekka Nikander > > _______________________________________________ > [email protected] mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "[email protected]" > _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
