From a91d74a3c4de8115295ee87350c13a329164aaaf Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 30 Jul 2009 16:03:45 -0600 Subject: lguest: update commentry Every so often, after code shuffles, I need to go through and unbitrot the Lguest Journey (see drivers/lguest/README). Since we now use RCU in a simple form in one place I took the opportunity to expand that explanation. Signed-off-by: Rusty Russell Cc: Ingo Molnar Cc: Paul McKenney --- drivers/lguest/hypercalls.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/lguest/hypercalls.c') diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c index 787ab4bc09f0..83511eb0923d 100644 --- a/drivers/lguest/hypercalls.c +++ b/drivers/lguest/hypercalls.c @@ -59,7 +59,7 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args) case LHCALL_SHUTDOWN: { char msg[128]; /* - * Shutdown is such a trivial hypercall that we do it in four + * Shutdown is such a trivial hypercall that we do it in five * lines right here. * * If the lgread fails, it will call kill_guest() itself; the @@ -245,6 +245,10 @@ static void initialize(struct lg_cpu *cpu) * device), the Guest will still see the old page. In practice, this never * happens: why would the Guest read a page which it has never written to? But * a similar scenario might one day bite us, so it's worth mentioning. + * + * Note that if we used a shared anonymous mapping in the Launcher instead of + * mapping /dev/zero private, we wouldn't worry about cop-on-write. And we + * need that to switch the Launcher to processes (away from threads) anyway. :*/ /*H:100 -- cgit v1.2.3