[src/trunk]: src/sys/rump/librump/rumpvfs rumpvfs:

[rmind <rmind%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/8db0b9c4955b
branches:  trunk
changeset: 779571:8db0b9c4955b
user:      rmind <rmind%NetBSD.org@localhost>
date:      Sun Jun 03 16:46:08 2012 +0000

description:
rumpvfs:
- ubc_uiomove: avoid the re-lock dance, since the lock is shared these days.
- uvm_aio_aiodone: acquire the lock before modifying the page flags.

Tested by martin@.

diffstat:

 sys/rump/librump/rumpvfs/vm_vfs.c |  59 ++++++++++++++++----------------------
 1 files changed, 25 insertions(+), 34 deletions(-)

diffs (168 lines):

diff -r 6fe176b64438 -r 8db0b9c4955b sys/rump/librump/rumpvfs/vm_vfs.c
--- a/sys/rump/librump/rumpvfs/vm_vfs.c Sun Jun 03 16:23:44 2012 +0000
+++ b/sys/rump/librump/rumpvfs/vm_vfs.c Sun Jun 03 16:46:08 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vm_vfs.c,v 1.32 2011/06/19 18:28:24 hannken Exp $      */
+/*     $NetBSD: vm_vfs.c,v 1.33 2012/06/03 16:46:08 rmind Exp $        */
 
 /*
  * Copyright (c) 2008-2011 Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vm_vfs.c,v 1.32 2011/06/19 18:28:24 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vm_vfs.c,v 1.33 2012/06/03 16:46:08 rmind Exp $");
 
 #include <sys/param.h>
 
@@ -44,7 +44,7 @@
 void
 uvm_aio_aiodone(struct buf *bp)
 {
-       struct uvm_object *uobj;
+       struct uvm_object *uobj = NULL;
        int i, npages = bp->b_bufsize >> PAGE_SHIFT;
        struct vm_page **pgs;
        vaddr_t va;
@@ -55,6 +55,15 @@
        for (i = 0; i < npages; i++) {
                va = (vaddr_t)bp->b_data + (i << PAGE_SHIFT);
                pgs[i] = uvm_pageratop(va);
+
+               if (uobj == NULL) {
+                       uobj = pgs[i]->uobject;
+                       KASSERT(uobj != NULL);
+                       mutex_enter(uobj->vmobjlock);
+               } else {
+                       KASSERT(uobj == pgs[i]->uobject);
+               }
+
                if (pgs[i]->flags & PG_PAGEOUT) {
                        KASSERT((pgs[i]->flags & PG_FAKE) == 0);
                        pageout++;
@@ -62,19 +71,14 @@
                        pgs[i]->flags |= PG_RELEASED;
                }
        }
-
-       uvm_pagermapout((vaddr_t)bp->b_data, npages);
+       KASSERT(mutex_owned(uobj->vmobjlock));
 
-       /* get uobj because we need it after pages might be recycled */
-       uobj = pgs[0]->uobject;
-       KASSERT(uobj);
-
-       mutex_enter(uobj->vmobjlock);
        mutex_enter(&uvm_pageqlock);
        uvm_page_unbusy(pgs, npages);
        mutex_exit(&uvm_pageqlock);
        mutex_exit(uobj->vmobjlock);
 
+       uvm_pagermapout((vaddr_t)bp->b_data, npages);
        uvm_pageout_done(pageout);
 
        if (BUF_ISWRITE(bp) && (bp->b_cflags & BC_AGE) != 0) {
@@ -105,7 +109,6 @@
 ubc_zerorange(struct uvm_object *uobj, off_t off, size_t len, int flags)
 {
        struct vm_page **pgs;
-       struct uvm_object *pguobj;
        int maxpages = MIN(32, round_page(len) >> PAGE_SHIFT);
        int rv, npages, i;
 
@@ -122,7 +125,8 @@
                    0, PAGERFLAGS | PGO_PASTEOF);
                KASSERT(npages > 0);
 
-               for (i = 0, pguobj = NULL; i < npages; i++) {
+               mutex_enter(uobj->vmobjlock);
+               for (i = 0; i < npages; i++) {
                        struct vm_page *pg;
                        uint8_t *start;
                        size_t chunkoff, chunklen;
@@ -130,9 +134,9 @@
                        pg = pgs[i];
                        if (pg == NULL)
                                break;
-                       if (pguobj == NULL)
-                               pguobj = pg->uobject;
-                       KASSERT(pguobj == pg->uobject);
+
+                       KASSERT(pg->uobject != NULL);
+                       KASSERT(uobj->vmobjlock == pg->uobject->vmobjlock);
 
                        chunkoff = off & PAGE_MASK;
                        chunklen = MIN(PAGE_SIZE - chunkoff, len);
@@ -144,17 +148,10 @@
                        off += chunklen;
                        len -= chunklen;
                }
-               mutex_enter(pguobj->vmobjlock);
                uvm_page_unbusy(pgs, npages);
-               if (pguobj != uobj) {
-                       mutex_exit(pguobj->vmobjlock);
-                       mutex_enter(uobj->vmobjlock);
-               }
        }
        mutex_exit(uobj->vmobjlock);
        kmem_free(pgs, maxpages * sizeof(pgs));
-
-       return;
 }
 
 #define len2npages(off, len)                                           \
@@ -165,7 +162,6 @@
        int advice, int flags)
 {
        struct vm_page **pgs;
-       struct uvm_object *pguobj;
        int npages = len2npages(uio->uio_offset, todo);
        size_t pgalloc;
        int i, rv, pagerflags;
@@ -193,7 +189,8 @@
                if (rv)
                        goto out;
 
-               for (i = 0, pguobj = NULL; i < npages; i++) {
+               mutex_enter(uobj->vmobjlock);
+               for (i = 0; i < npages; i++) {
                        struct vm_page *pg;
                        size_t xfersize;
                        off_t pageoff;
@@ -201,31 +198,25 @@
                        pg = pgs[i];
                        if (pg == NULL)
                                break;
-                       if (pguobj == NULL)
-                               pguobj = pg->uobject;
-                       KASSERT(pguobj == pg->uobject);
 
+                       KASSERT(pg->uobject != NULL);
+                       KASSERT(uobj->vmobjlock == pg->uobject->vmobjlock);
                        pageoff = uio->uio_offset & PAGE_MASK;
+
                        xfersize = MIN(MIN(todo, PAGE_SIZE), PAGE_SIZE-pageoff);
                        KASSERT(xfersize > 0);
                        rv = uiomove((uint8_t *)pg->uanon + pageoff,
                            xfersize, uio);
                        if (rv) {
-                               mutex_enter(pguobj->vmobjlock);
                                uvm_page_unbusy(pgs, npages);
-                               mutex_exit(pguobj->vmobjlock);
+                               mutex_exit(uobj->vmobjlock);
                                goto out;
                        }
                        if (uio->uio_rw == UIO_WRITE)
                                pg->flags &= ~(PG_CLEAN | PG_FAKE);
                        todo -= xfersize;
                }
-               mutex_enter(pguobj->vmobjlock);
                uvm_page_unbusy(pgs, npages);
-               if (pguobj != uobj) {
-                       mutex_exit(pguobj->vmobjlock);
-                       mutex_enter(uobj->vmobjlock);
-               }
        } while (todo);
        mutex_exit(uobj->vmobjlock);