d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make vm_page's PG_ZERO flag immutable between the time of the page's

Browse Source 
allocation and deallocation.  This flag's principal use is shortly after
allocation.  For such cases, clearing the flag is pointless.  The only
unusual use of PG_ZERO is in vfs_bio_clrbuf().  However, allocbuf() never
requests a prezeroed page.  So, vfs_bio_clrbuf() never sees a prezeroed
page.

Reviewed by:	tegge@
This commit is contained in:
Alan Cox 2004-05-06 05:03:23 +00:00
parent 2fb3498126
commit 5a32489377
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=128992
9 changed files with 1 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
sys/fs/nwfs/nwfs_io.c
View File

@ -464,8 +464,6 @@ nwfs_getpages(ap)
nextoff = toff + PAGE_SIZE;
m = pages[i];
m->flags &= ~PG_ZERO;
if (nextoff <= size) {
m->valid = VM_PAGE_BITS_ALL;
m->dirty = 0;

2
sys/fs/smbfs/smbfs_io.c
View File

@ -517,8 +517,6 @@ smbfs_getpages(ap)
nextoff = toff + PAGE_SIZE;
m = pages[i];
m->flags &= ~PG_ZERO;
if (nextoff <= size) {
/*
* Read operation filled an entire page

2
sys/fs/specfs/spec_vnops.c
View File

@ -780,8 +780,6 @@ spec_getpages(ap)
nextoff = toff + PAGE_SIZE;
m = ap->a_m[i];
m->flags &= ~PG_ZERO;
if (nextoff <= nread) {
m->valid = VM_PAGE_BITS_ALL;
vm_page_undirty(m);

1
sys/kern/uipc_syscalls.c
View File

@ -1893,7 +1893,6 @@ do_sendfile(struct thread *td, struct sendfile_args *uap, int compat)
if (error)
VM_OBJECT_LOCK(obj);
vm_page_lock_queues();
vm_page_flag_clear(pg, PG_ZERO);
vm_page_io_finish(pg);
mbstat.sf_iocnt++;
}

15
sys/kern/vfs_bio.c
View File

@ -1336,9 +1336,6 @@ brelse(struct buf * bp)
int had_bogus = 0;
m = bp->b_pages[i];
vm_page_lock_queues();
vm_page_flag_clear(m, PG_ZERO);
vm_page_unlock_queues();
/*
* If we hit a bogus page, fixup *all* the bogus pages
@ -1582,7 +1579,6 @@ vfs_vmio_release(bp)
continue;
if (m->wire_count == 0) {
vm_page_flag_clear(m, PG_ZERO);
/*
* Might as well free the page if we can and it has
* no valid data. We also free the page if the
@ -2326,10 +2322,8 @@ vfs_setdirty(struct buf *bp)
* test the pages to see if they have been modified directly
* by users through the VM system.
*/
for (i = 0; i < bp->b_npages; i++) {
vm_page_flag_clear(bp->b_pages[i], PG_ZERO);
for (i = 0; i < bp->b_npages; i++)
vm_page_test_dirty(bp->b_pages[i]);
}
/*
* Calculate the encompassing dirty range, boffset and eoffset,
@ -2919,7 +2913,6 @@ allocbuf(struct buf *bp, int size)
(cnt.v_free_min + cnt.v_cache_min))) {
pagedaemon_wakeup();
}
vm_page_flag_clear(m, PG_ZERO);
vm_page_wire(m);
vm_page_unlock_queues();
bp->b_pages[bp->b_npages] = m;
@ -3233,7 +3226,6 @@ bufdone(struct buf *bp)
if ((bp->b_iocmd == BIO_READ) && !bogusflag && resid > 0) {
vfs_page_set_valid(bp, foff, i, m);
}
vm_page_flag_clear(m, PG_ZERO);
/*
* when debugging new filesystems or buffer I/O methods, this
@ -3316,7 +3308,6 @@ vfs_unbusy_pages(struct buf * bp)
pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages);
}
vm_object_pip_subtract(obj, 1);
vm_page_flag_clear(m, PG_ZERO);
vm_page_io_finish(m);
}
vm_page_unlock_queues();
@ -3402,7 +3393,6 @@ vfs_busy_pages(struct buf * bp, int clear_modify)
for (i = 0; i < bp->b_npages; i++) {
vm_page_t m = bp->b_pages[i];
vm_page_flag_clear(m, PG_ZERO);
if ((bp->b_flags & B_CLUSTER) == 0) {
vm_object_pip_add(obj, 1);
vm_page_io_start(m);
@ -3579,9 +3569,6 @@ vfs_bio_clrbuf(struct buf *bp)
}
}
bp->b_pages[i]->valid |= mask;
vm_page_lock_queues();
vm_page_flag_clear(bp->b_pages[i], PG_ZERO);
vm_page_unlock_queues();
}
unlock:
VM_OBJECT_UNLOCK(bp->b_object);

2
sys/nfsclient/nfs_bio.c
View File

@ -215,8 +215,6 @@ nfs_getpages(struct vop_getpages_args *ap)
nextoff = toff + PAGE_SIZE;
m = pages[i];
m->flags &= ~PG_ZERO;
if (nextoff <= size) {
/*
* Read operation filled an entire page

4
sys/vm/swap_pager.c
View File

@ -1483,7 +1483,6 @@ swp_pager_async_iodone(struct buf *bp)
* interrupt.
*/
m->valid = 0;
vm_page_flag_clear(m, PG_ZERO);
if (i != bp->b_pager.pg_reqpage)
vm_page_free(m);
else
@ -1516,8 +1515,6 @@ swp_pager_async_iodone(struct buf *bp)
* that existed in the old swapper for a time before
* it got ripped out due to precisely this problem.
*
* clear PG_ZERO in page.
*
* If not the requested page then deactivate it.
*
* Note that the requested page, reqpage, is left
@ -1529,7 +1526,6 @@ swp_pager_async_iodone(struct buf *bp)
pmap_clear_modify(m);
m->valid = VM_PAGE_BITS_ALL;
vm_page_undirty(m);
vm_page_flag_clear(m, PG_ZERO);
/*
* We have to wake specifically requested pages

1
sys/vm/vm_fault.c
View File

@ -898,7 +898,6 @@ RetryFault:;
}
mtx_unlock(&Giant);
vm_page_lock_queues();
vm_page_flag_clear(fs.m, PG_ZERO);
vm_page_flag_set(fs.m, PG_REFERENCED);
/*

3
sys/vm/vnode_pager.c
View File

@ -513,7 +513,6 @@ vnode_pager_input_smlfs(object, m)
sf_buf_free(sf);
vm_page_lock_queues();
pmap_clear_modify(m);
vm_page_flag_clear(m, PG_ZERO);
vm_page_unlock_queues();
if (error) {
return VM_PAGER_ERROR;
@ -586,7 +585,6 @@ vnode_pager_input_old(object, m)
vm_page_lock_queues();
pmap_clear_modify(m);
vm_page_undirty(m);
vm_page_flag_clear(m, PG_ZERO);
vm_page_unlock_queues();
if (!error)
m->valid = VM_PAGE_BITS_ALL;
@ -884,7 +882,6 @@ vnode_pager_generic_getpages(vp, m, bytecount, reqpage)
/* vm_page_zero_invalid(mt, FALSE); */
}
vm_page_flag_clear(mt, PG_ZERO);
if (i != reqpage) {
/*