svn commit: r193044 - head/sys/kern
Alan Cox
alc at FreeBSD.org
Fri May 29 18:35:52 UTC 2009
Author: alc
Date: Fri May 29 18:35:51 2009
New Revision: 193044
URL: http://svn.freebsd.org/changeset/base/193044
Log:
Modify vm_hold_load_pages() to allocate pages using VM_ALLOC_NOOBJ rather
than using the kernel object. This allows the elimination of page queues
locking from vm_hold_free_pages().
Modified:
head/sys/kern/vfs_bio.c
Modified: head/sys/kern/vfs_bio.c
==============================================================================
--- head/sys/kern/vfs_bio.c Fri May 29 16:24:23 2009 (r193043)
+++ head/sys/kern/vfs_bio.c Fri May 29 18:35:51 2009 (r193044)
@@ -3796,30 +3796,25 @@ vm_hold_load_pages(struct buf *bp, vm_of
from = round_page(from);
index = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT;
- VM_OBJECT_LOCK(kernel_object);
for (pg = from; pg < to; pg += PAGE_SIZE, index++) {
tryagain:
/*
* note: must allocate system pages since blocking here
- * could intefere with paging I/O, no matter which
+ * could interfere with paging I/O, no matter which
* process we are.
*/
- p = vm_page_alloc(kernel_object,
- ((pg - VM_MIN_KERNEL_ADDRESS) >> PAGE_SHIFT),
- VM_ALLOC_NOBUSY | VM_ALLOC_SYSTEM | VM_ALLOC_WIRED);
+ p = vm_page_alloc(NULL, pg >> PAGE_SHIFT, VM_ALLOC_NOOBJ |
+ VM_ALLOC_SYSTEM | VM_ALLOC_WIRED);
if (!p) {
atomic_add_int(&vm_pageout_deficit,
(to - pg) >> PAGE_SHIFT);
- VM_OBJECT_UNLOCK(kernel_object);
VM_WAIT;
- VM_OBJECT_LOCK(kernel_object);
goto tryagain;
}
p->valid = VM_PAGE_BITS_ALL;
pmap_qenter(pg, &p, 1);
bp->b_pages[index] = p;
}
- VM_OBJECT_UNLOCK(kernel_object);
bp->b_npages = index;
}
@@ -3835,7 +3830,6 @@ vm_hold_free_pages(struct buf *bp, vm_of
to = round_page(to);
newnpages = index = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT;
- VM_OBJECT_LOCK(kernel_object);
for (pg = from; pg < to; pg += PAGE_SIZE, index++) {
p = bp->b_pages[index];
if (p && (index < bp->b_npages)) {
@@ -3847,13 +3841,11 @@ vm_hold_free_pages(struct buf *bp, vm_of
}
bp->b_pages[index] = NULL;
pmap_qremove(pg, 1);
- vm_page_lock_queues();
- vm_page_unwire(p, 0);
+ p->wire_count--;
vm_page_free(p);
- vm_page_unlock_queues();
+ atomic_subtract_int(&cnt.v_wire_count, 1);
}
}
- VM_OBJECT_UNLOCK(kernel_object);
bp->b_npages = newnpages;
}
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