From 3a50d97c5c165f2ee59b643bb0e70f8646bbdaa6 Mon Sep 17 00:00:00 2001
From: alc <alc@FreeBSD.org>
Date: Sun, 9 Mar 2003 20:38:56 +0000
Subject: [PATCH] Remove some unnecessary actions by the zero-copy setup and
teardown code. Remove an incorrect comment. (Incrementing an object's
reference count does not prevent a process from exiting. The real concern
here is that the physical page must not be deleted until transmission is
complete. That is already handled by the VM system and sf_buf_free().)
Tested by: ken
---
sys/kern/uipc_cow.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/sys/kern/uipc_cow.c b/sys/kern/uipc_cow.c
index 21701e0f597b..dfe2c8690ce3 100644
--- a/sys/kern/uipc_cow.c
+++ b/sys/kern/uipc_cow.c
@@ -87,19 +87,15 @@ socow_iodone(void *addr, void *args)
{
int s;
struct sf_buf *sf;
-
- vm_offset_t paddr;
vm_page_t pp;
sf = dtosf(addr);
- paddr = vtophys((vm_offset_t)addr);
- pp = PHYS_TO_VM_PAGE(paddr);
+ pp = sf->m;
s = splvm();
/* remove COW mapping */
vm_page_lock_queues();
vm_page_cowclear(pp);
vm_page_unlock_queues();
- vm_object_deallocate(pp->object);
splx(s);
/* note that sf_buf_free() unwires the page for us*/
sf_buf_free(addr, NULL);
@@ -152,11 +148,6 @@ socow_setup(struct mbuf *m0, struct uio *uio)
vm_page_wire(pp);
vm_page_unlock_queues();
- /*
- * prevent the process from exiting on us.
- */
- vm_object_reference(pp->object);
-
/*
* attach to mbuf
*/