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Pass the vm_page's address to sf_buf_alloc(); map the vm_page as part

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of sf_buf_alloc() instead of expecting sf_buf_alloc()'s caller to map it.

The ultimate reason for this change is to enable two optimizations:
(1) that there never be more than one sf_buf mapping a vm_page at a time
and (2) 64-bit architectures can transparently use their 1-1 virtual
to physical mapping (e.g., "K0SEG") avoiding the overhead of pmap_qenter()
and pmap_qremove().
This commit is contained in:
alc 2003-03-29 06:14:14 +00:00
parent 7d7faf316e
commit 6f59be774d
3 changed files with 8 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
sys/kern/uipc_cow.c
View File

@ -144,9 +144,7 @@ socow_setup(struct mbuf *m0, struct uio *uio)
/*
* Allocate an sf buf
*/
sf = sf_buf_alloc();
sf->m = pp;
pmap_qenter(sf->kva, &pp, 1);
sf = sf_buf_alloc(pp);
/*
* attach to mbuf

15
sys/kern/uipc_syscalls.c
View File

@ -1637,7 +1637,7 @@ sf_buf_init(void *arg)
* Get an sf_buf from the freelist. Will block if none are available.
*/
struct sf_buf *
sf_buf_alloc()
sf_buf_alloc(struct vm_page *m)
{
struct sf_buf *sf;
int error;
@ -1655,8 +1655,11 @@ sf_buf_alloc()
if (error)
break;
}
if (sf != NULL)
if (sf != NULL) {
SLIST_REMOVE_HEAD(&sf_freelist.sf_head, free_list);
sf->m = m;
pmap_qenter(sf->kva, &sf->m, 1);
}
mtx_unlock(&sf_freelist.sf_lock);
return (sf);
}
@ -1930,7 +1933,7 @@ do_sendfile(struct thread *td, struct sendfile_args *uap, int compat)
* Get a sendfile buf. We usually wait as long as necessary,
* but this wait can be interrupted.
*/
if ((sf = sf_buf_alloc()) == NULL) {
if ((sf = sf_buf_alloc(pg)) == NULL) {
vm_page_lock_queues();
vm_page_unwire(pg, 0);
if (pg->wire_count == 0 && pg->object == NULL)
@ -1941,12 +1944,6 @@ do_sendfile(struct thread *td, struct sendfile_args *uap, int compat)
goto done;
}
/*
* Allocate a kernel virtual page and insert the physical page
* into it.
*/
sf->m = pg;
pmap_qenter(sf->kva, &pg, 1);
/*
* Get an mbuf header and set it up as having external storage.
*/

2
sys/sys/socketvar.h
View File

@ -371,7 +371,7 @@ int sbreserve(struct sockbuf *sb, u_long cc, struct socket *so,
void sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb);
int sbwait(struct sockbuf *sb);
struct sf_buf *
sf_buf_alloc(void);
sf_buf_alloc(struct vm_page *m);
void sf_buf_free(void *addr, void *args);
int sb_lock(struct sockbuf *sb);
int soabort(struct socket *so);