Skip site navigation (1)Skip section navigation (2) 
Date:      Fri, 29 May 2009 18:35:51 +0000 (UTC)
From:      Alan Cox <alc@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r193044 - head/sys/kern
Message-ID:  <200905291835.n4TIZpIQ082882@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help 
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;
 }

Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200905291835.n4TIZpIQ082882>