diff options
| author | dg <dg@FreeBSD.org> | 1994-10-04 03:05:09 +0000 |
|---|---|---|
| committer | dg <dg@FreeBSD.org> | 1994-10-04 03:05:09 +0000 |
| commit | 467ebd68491cd821e382a8d83357a6e4e56130d2 (patch) | |
| tree | 7c44bb0a3e72fbd64bd379fd64cd8dcae2a744bb | |
| parent | 8a19acef0be008d6d541b694f0de5a0b152d1a8e (diff) | |
| download | FreeBSD-src-467ebd68491cd821e382a8d83357a6e4e56130d2.zip FreeBSD-src-467ebd68491cd821e382a8d83357a6e4e56130d2.tar.gz | |
Fixed bug related to proper sensing of page modification that we
inadvertantly introduced in pre-1.1.5. This could cause page modifications
to go unnoticed during certain extreme low memory/high paging rate conditions.
Submitted by: John Dyson and David Greenman
| -rw-r--r-- | sys/vm/vm_pageout.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c index d2d805f..dac738c 100644 --- a/sys/vm/vm_pageout.c +++ b/sys/vm/vm_pageout.c @@ -65,7 +65,7 @@ * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. * - * $Id: vm_pageout.c,v 1.11 1994/09/12 11:31:36 davidg Exp $ + * $Id: vm_pageout.c,v 1.12 1994/09/12 15:06:14 davidg Exp $ */ /* @@ -646,15 +646,16 @@ rescan1: } /* - * if page is clean and but the page has been referenced, - * then reactivate the page, but if we are very low on memory - * or the page has not been referenced, then we free it to the - * vm system. + * NOTE: PG_CLEAN doesn't guarantee that the page is clean. */ if (m->flags & PG_CLEAN) { - if ((cnt.v_free_count > vm_pageout_free_min) /* XXX */ - && ((pmap_is_referenced(VM_PAGE_TO_PHYS(m)) || - (m->flags & PG_REFERENCED) != 0))) { + /* + * If we're not low on memory and the page has been reference, + * or if the page has been modified, then reactivate the page. + */ + if (((cnt.v_free_count > vm_pageout_free_min) && + (pmap_is_referenced(VM_PAGE_TO_PHYS(m)) || ((m->flags & PG_REFERENCED) != 0))) || + pmap_is_modified(VM_PAGE_TO_PHYS(m))) { m->flags &= ~PG_REFERENCED; vm_page_activate(m); } else if (!m->act_count) { |
