Diego Roversi <[EMAIL PROTECTED]> writes: > I think that storeio is the only possibility to put a cache mechanism in > user space. But I see some drawbacks: > - memory user for caching can be paged out
If that happens, you're doing it wrong, I think. You want to use a special pager for the cache. When the kernel tells the pager to page out a page in your cache (my understanding of the details on how this happens is very vague), you don't want to write it to the swap, you can just throw it away, and reread it from the original location when it is accessed the next time (ok, that's for read-only access, but that's the simplest case). And that's exactly what mmap is supposed to do. I'm not sure what parts of mmap are done in Mach and how much of it is done in various hurd components, but I hope you can reuse or at least learn from that code. On the other hand, AFAIK, ext2fs *is* already mmapping the entire device (that's the source of the current limit on partition size), so I don't know why we're having this problem. Perhaps the general mmapping mechanisms can be improved to cache better? Regards, /Niels _______________________________________________ Bug-hurd mailing list [EMAIL PROTECTED] http://mail.gnu.org/mailman/listinfo/bug-hurd
