Author: alc
Date: Sun Jul 11 20:11:44 2010
New Revision: 209902
URL: http://svn.freebsd.org/changeset/base/209902
Log:
Change the implementation of vm_hold_free_pages() so that it performs at
most one call to pmap_qremove(), and thus one TLB shootdown, instead of one
call and TLB shootdown per page.
Simplify the interface to vm_hold_free_pages().
MFC after: 3 weeks
Modified:
head/sys/kern/vfs_bio.c
Modified: head/sys/kern/vfs_bio.c
==============================================================================
--- head/sys/kern/vfs_bio.c Sun Jul 11 17:08:37 2010 (r209901)
+++ head/sys/kern/vfs_bio.c Sun Jul 11 20:11:44 2010 (r209902)
@@ -95,8 +95,7 @@ struct buf *buf; /* buffer header pool
static struct proc *bufdaemonproc;
static int inmem(struct vnode *vp, daddr_t blkno);
-static void vm_hold_free_pages(struct buf *bp, vm_offset_t from,
- vm_offset_t to);
+static void vm_hold_free_pages(struct buf *bp, int newbsize);
static void vm_hold_load_pages(struct buf *bp, vm_offset_t from,
vm_offset_t to);
static void vfs_page_set_valid(struct buf *bp, vm_ooffset_t off, vm_page_t m);
@@ -2888,10 +2887,7 @@ allocbuf(struct buf *bp, int size)
}
return 1;
}
- vm_hold_free_pages(
- bp,
- (vm_offset_t) bp->b_data + newbsize,
- (vm_offset_t) bp->b_data + bp->b_bufsize);
+ vm_hold_free_pages(bp, newbsize);
} else if (newbsize > bp->b_bufsize) {
/*
* We only use malloced memory on the first allocation.
@@ -3766,31 +3762,25 @@ tryagain:
/* Return pages associated with this buf to the vm system */
static void
-vm_hold_free_pages(struct buf *bp, vm_offset_t from, vm_offset_t to)
+vm_hold_free_pages(struct buf *bp, int newbsize)
{
- vm_offset_t pg;
+ vm_offset_t from;
vm_page_t p;
int index, newnpages;
- from = round_page(from);
- to = round_page(to);
- newnpages = index = (from - trunc_page((vm_offset_t)bp->b_data)) >>
PAGE_SHIFT;
-
- for (pg = from; pg < to; pg += PAGE_SIZE, index++) {
+ from = round_page((vm_offset_t)bp->b_data + newbsize);
+ newnpages = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT;
+ if (bp->b_npages > newnpages)
+ pmap_qremove(from, bp->b_npages - newnpages);
+ for (index = newnpages; index < bp->b_npages; index++) {
p = bp->b_pages[index];
- if (p && (index < bp->b_npages)) {
- if (p->busy) {
- printf(
- "vm_hold_free_pages: blkno: %jd, lblkno: %jd\n",
- (intmax_t)bp->b_blkno,
- (intmax_t)bp->b_lblkno);
- }
- bp->b_pages[index] = NULL;
- pmap_qremove(pg, 1);
- p->wire_count--;
- vm_page_free(p);
- atomic_subtract_int(&cnt.v_wire_count, 1);
- }
+ bp->b_pages[index] = NULL;
+ if (p->busy != 0)
+ printf("vm_hold_free_pages: blkno: %jd, lblkno: %jd\n",
+ (intmax_t)bp->b_blkno, (intmax_t)bp->b_lblkno);
+ p->wire_count--;
+ vm_page_free(p);
+ atomic_subtract_int(&cnt.v_wire_count, 1);
}
bp->b_npages = newnpages;
}
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
