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@@ -33,6 +33,16 @@ Also see [[device drivers and IO systems]].
to IRQs. However, at least in GNU Mach, that code (`kern/eventcount.c`)
doesn't seem functional at all and isn't integrated properly in the kernel.
+ * IRC, freenode, #hurd, 2011-07-29
+
+ < antrik> regarding performance of userspace drivers, there is one
+ thing that really adds considerable overhead: interrupt
+ handling. whether this is relevant very much depends on the hardware
+ in question. when sending many small packets over gigabit ethernet,
+ it might be noticable; in most other cases it's irrelevant
+ < youpi> some cards support interrupt coalescin
+ < youpi> could be supported by DDE too
+
## DMA
* Security considerations.
@@ -52,6 +62,32 @@ Also see [[device drivers and IO systems]].
* [[GNU Mach|microkernel/mach/gnumach]] is said to have a high overhead when
doing RPC calls.
+## System Boot
+
+IRC, freenode, #hurd, 2011-07-27
+
+ < braunr> btw, was there any formulation of the modifications required to
+ have disk drivers in userspace ?
+ < braunr> (which would obviously need something like
+ initrd/initramfs/whatever and may also need the root file system not to
+ be the first task started)
+ < braunr> hm actually, we may not need initrd
+ < braunr> the boot loader could just load more modules
+ < antrik> braunr: I have described all that in my thesis report... in
+ German :-(
+ < braunr> and the boot scripts could be adjusted to pass around the right
+ ports
+ < Tekk_> braunr: yeah, we could probably load a module that kciks us into
+ userspace and starts the disk driver
+ < braunr> modules are actualy userspace executables
+ < Tekk_> ah
+ < Tekk_> so what's the issue?
+ < Tekk_> oh! I'm thinking the ext2fs server, which is already in userspce
+ < braunr> change the file systems to tell them which underlying disk driver
+ to use
+ < Tekk_> mhm
+ < braunr> s/disk/storage/
+
# Plan