On Mon, Dec 04, 2000 at 10:51:07AM -0600, Ezequiel Reyes wrote: > *This message was transferred with a trial version of CommuniGate(tm) Pro* > > If you must choose between misc. microkernels, the perspective changes: > > Mach is a ukernel with a rich set of semantics. Therefore it is bloated > > and not so small than a ukernel should be. They are other microkernels > > that are much smaller and that provide for faster context switches. > > First of all, thank you for helping this newbie, your explanation have been > very clear to me, there are still two questions I would like to ask about > what you say of Mach offering more services than The Hurd really needs. > first: is all this extra-functionality still present in the GNU version of > Mach the Hurd currently uses or has it been removed for the sake of resource > consumption ? > second: if it hasn't been removed, is it just because the complexity of the > whole microkernel doesn't allow it without compromising cleanliness or > stability?
I do not think removing a few functions would make any kind of difference -- if they are that slow avoid using them. The reason the L4 people claim that Mach is so slow is that it uses async ipc messages. What does that mean? I send a message to you. Inside the message, I send a reply port. After I send the message, I wait on the reply port until you send me the result. In L4 they have (only) synchronous messages based on your tid (thread id) so when you send a message, it is ``easier'' to optimize. -Neal -- Neal H Walfield University of Massachusetts at Lowell [EMAIL PROTECTED] or [EMAIL PROTECTED]
