allow skipping some cache flushes in proc

3 files changed, 5 insertions, 19 deletions

diff --git a/src/elf.c b/src/elf.c
index 85b4b2e..f643d41 100644
--- a/src/elf.c
+++ b/src/elf.c
@@ -93,10 +93,9 @@ static stat_t __map_exec(struct tcb *t,
 
 	/* create empty vmem so we don't have to worry about possible overlaps */
 	struct vmem *new_vmem = create_vmem();
-	if (!new_vmem) {
-		use_vmem(t->rpc.vmem);
+	if (!new_vmem)
 		return ERR_OOMEM;
-	}
+
 	struct vmem *old_vmem = t->proc.vmem;
 	t->proc.vmem = new_vmem;
 
diff --git a/src/uapi/ipc.c b/src/uapi/ipc.c
index 3f94e63..e323478 100644
--- a/src/uapi/ipc.c
+++ b/src/uapi/ipc.c
@@ -61,7 +61,7 @@ static __inline void enter_rpc(struct tcb *t, struct tcb *r, struct sys_ret a,
 
 	/* try to get rid of args as fast as possible to free up registers for
 	 * later use */
-	set_ret(t, 6, a);
+	set_ret_fast(t, a);
 
 	if (!is_set(flags, IPC_TAIL)) {
 		ctx->rpc_stack = t->rpc_stack;
@@ -79,7 +79,7 @@ static __inline void enter_rpc(struct tcb *t, struct tcb *r, struct sys_ret a,
 	}
 
 
-	set_stack(t, rpc_stack - BASE_PAGE_SIZE);
+	set_stack_fast(t, rpc_stack - BASE_PAGE_SIZE);
 	clone_uvmem(r->proc.vmem, t->rpc.vmem);
 	flush_tlb_full();
 
@@ -203,7 +203,7 @@ static void leave_rpc(struct tcb *t, struct sys_ret a)
 
 	/* again, get rid of args as fast as possible */
 	if (!ctx->notify)
-		set_ret(t, 6, a);
+		set_ret_fast(t, a);
 
 	struct tcb *r = get_tcb(ctx->pid);
 	while (!r || !is_proc(r) || zombie(r)) {
diff --git a/src/uapi/proc.c b/src/uapi/proc.c
index 4b6865c..52511f9 100644
--- a/src/uapi/proc.c
+++ b/src/uapi/proc.c
@@ -46,18 +46,12 @@ SYSCALL_DEFINE5(create)(struct tcb *t, sys_arg_t func,
 	if (!n)
 		return_args1(t, ERR_OOMEM);
 
-	/* temporarily jump into new thread memory to set arguments */
-	use_vmem(n->rpc.vmem);
-
 	/* this visit is likely not the cheapest thing in the universe, are
 	 * there ways to speed up thread creation? */
 	set_thread(n);
 	set_ret5(n, n->tid, d0, d1, d2, d3);
 	set_return(n, func);
 
-	/* return back */
-	use_vmem(t->rpc.vmem);
-
 	n->notify_id = t->notify_id;
 	return_args1(t, n->tid);
 }
@@ -91,13 +85,9 @@ SYSCALL_DEFINE0(fork)(struct tcb *t)
 	if (!n)
 		return_args1(t, ERR_OOMEM);
 
-	/* again, probably not fantastic that we're jumping between address
-	 * spaces like this */
-	use_vmem(n->rpc.vmem);
 	/* prepare args for when we eventually swap to the new proc, giving
 	 * parent ID as third return value */
 	set_args2(n, 0, get_eproc(t)->pid);
-	use_vmem(t->rpc.vmem);
 
 	n->notify_id = c->notify_id;
 	return_args1(t, n->pid);
@@ -180,12 +170,9 @@ SYSCALL_DEFINE2(spawn)(struct tcb *t, sys_arg_t bin, sys_arg_t interp)
 	/** @todo should permissions be transferred? Probably, not but now there
 	 * is a slightly annoying asymmetry between fork+exec vs spawn... */
 
-	/* temporarily switch to new thread to manipulate stack */
-	use_vmem(n->rpc.vmem);
 	set_thread(n);
 	set_return(n, n->callback);
 	set_ret4(n, 0, n->tid, SYS_USER_SPAWNED, n->pid);
-	use_vmem(t->rpc.vmem);
 
 	return_args1(t, n->pid);
 }