Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!



Hurd: H2 CD Images

Breace Re:speed? (312 comments)

I don't really see why a microkernel can not have access to userland buffers and a monolithic kernel can.

Maybe QNX 4 (different from Neutrino, which is the current QNX) was not very smart, I don't know. And I personally am not hot on message passing either, but QNX remains a good example of message-passing microkernels being to perform relatively good.

But when you say: Because the driver is a user process, it simply can't do the kind of memory mapping that a Unix kernel can do to grab userland data

I would have to disagree. The kernel could easily provide services that would provide memory mapping to the driver. I don't see why not. In fact, with proper protection mechanisms in place there's no reason why any user app should not be able to figure out real memory addresses. I don't think that would be ugly.

more than 12 years ago


Breace hasn't submitted any stories.


Breace has no journal entries.

Slashdot Login

Need an Account?

Forgot your password?

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>