1
linux/drivers/lguest
Rusty Russell 7b21e34fd1 virtio: harsher barriers for rpmsg.
We were cheating with our barriers; using the smp ones rather than the
real device ones.  That was fine, until rpmsg came along, which is
used to talk to a real device (a non-SMP CPU).

Unfortunately, just putting back the real barriers (reverting
d57ed95d) causes a performance regression on virtio-pci.  In
particular, Amos reports netbench's TCP_RR over virtio_net CPU
utilization increased up to 35% while throughput went down by up to
14%.

By comparison, this branch is in the noise.

Reference: https://lkml.org/lkml/2011/12/11/22

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:42 +10:30
..
x86 x86: Fix rflags in FAKE_STACK_FRAME 2011-12-06 10:02:38 +01:00
core.c lguest: move process freezing before pending signals check 2011-10-27 10:56:18 +10:30
hypercalls.c
interrupts_and_traps.c lguest: update comments 2011-07-22 14:39:50 +09:30
Kconfig Correct occurrences of 2011-05-06 09:27:55 -07:00
lg.h lguest: use a special 1:1 linear pagetable mode until first switch. 2011-07-22 14:39:48 +09:30
lguest_device.c virtio: harsher barriers for rpmsg. 2012-01-12 15:44:42 +10:30
lguest_user.c lguest: add export.h to lguest files for THIS_MODULE/EXPORT_SYMBOL 2011-10-31 19:32:13 -04:00
Makefile Correct occurrences of 2011-05-06 09:27:55 -07:00
page_tables.c lguest: update comments 2011-07-22 14:39:50 +09:30
README
segments.c

Welcome, friend reader, to lguest.

Lguest is an adventure, with you, the reader, as Hero.  I can't think of many
5000-line projects which offer both such capability and glimpses of future
potential; it is an exciting time to be delving into the source!

But be warned; this is an arduous journey of several hours or more!  And as we
know, all true Heroes are driven by a Noble Goal.  Thus I offer a Beer (or
equivalent) to anyone I meet who has completed this documentation.

So get comfortable and keep your wits about you (both quick and humorous).
Along your way to the Noble Goal, you will also gain masterly insight into
lguest, and hypervisors and x86 virtualization in general.

Our Quest is in seven parts: (best read with C highlighting turned on)

I) Preparation
	- In which our potential hero is flown quickly over the landscape for a
	  taste of its scope.  Suitable for the armchair coders and other such
	  persons of faint constitution.

II) Guest
	- Where we encounter the first tantalising wisps of code, and come to
	  understand the details of the life of a Guest kernel.

III) Drivers
	- Whereby the Guest finds its voice and become useful, and our
	  understanding of the Guest is completed.

IV) Launcher
	- Where we trace back to the creation of the Guest, and thus begin our
	  understanding of the Host.

V) Host
	- Where we master the Host code, through a long and tortuous journey.
	  Indeed, it is here that our hero is tested in the Bit of Despair.

VI) Switcher
	- Where our understanding of the intertwined nature of Guests and Hosts
	  is completed.

VII) Mastery
	- Where our fully fledged hero grapples with the Great Question:
	  "What next?"

make Preparation!
Rusty Russell.