Author: kib
Date: Fri Nov 26 15:30:02 2010
New Revision: 215866
URL: http://svn.freebsd.org/changeset/base/215866

Log:
  MFC r215471:
  In vm_object_page_clean(), handle the pages that might be cached
  or not written by vm_pageout_flush().
  
  MFC r215574:
  The runlen returned from vm_pageout_flush() might be zero legitimately
  
  MCF r215610:
  Eliminate the mab, maf arrays and related variables.
  The change also fixes off-by-one error in the calculation of mreq.
  
  MFC r215796:
  After the sleep caused by encountering a busy page, relookup the page.

Modified:
  stable/8/sys/vm/vm_contig.c
  stable/8/sys/vm/vm_object.c
  stable/8/sys/vm/vm_pageout.c
  stable/8/sys/vm/vm_pageout.h
Directory Properties:
  stable/8/sys/   (props changed)
  stable/8/sys/amd64/include/xen/   (props changed)
  stable/8/sys/cddl/contrib/opensolaris/   (props changed)
  stable/8/sys/contrib/dev/acpica/   (props changed)
  stable/8/sys/contrib/pf/   (props changed)

Modified: stable/8/sys/vm/vm_contig.c
==============================================================================
--- stable/8/sys/vm/vm_contig.c Fri Nov 26 14:50:42 2010        (r215865)
+++ stable/8/sys/vm/vm_contig.c Fri Nov 26 15:30:02 2010        (r215866)
@@ -138,7 +138,7 @@ vm_contig_launder_page(vm_page_t m, vm_p
                } else if (object->type == OBJT_SWAP ||
                           object->type == OBJT_DEFAULT) {
                        m_tmp = m;
-                       vm_pageout_flush(&m_tmp, 1, VM_PAGER_PUT_SYNC);
+                       vm_pageout_flush(&m_tmp, 1, VM_PAGER_PUT_SYNC, 0, NULL);
                        VM_OBJECT_UNLOCK(object);
                        return (0);
                }

Modified: stable/8/sys/vm/vm_object.c
==============================================================================
--- stable/8/sys/vm/vm_object.c Fri Nov 26 14:50:42 2010        (r215865)
+++ stable/8/sys/vm/vm_object.c Fri Nov 26 15:30:02 2010        (r215866)
@@ -809,10 +809,12 @@ rescan:
                np = TAILQ_NEXT(p, listq);
                if (p->valid == 0)
                        continue;
-               while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) {
+               if (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) {
                        vm_page_lock_queues();
                        if (object->generation != curgeneration)
                                goto rescan;
+                       np = vm_page_find_least(object, pi);
+                       continue;
                }
                vm_page_test_dirty(p);
                if (p->dirty == 0)
@@ -828,7 +830,6 @@ rescan:
                        continue;
 
                n = vm_object_page_collect_flush(object, p, pagerflags);
-               KASSERT(n > 0, ("vm_object_page_collect_flush failed"));
                if (object->generation != curgeneration)
                        goto rescan;
                np = vm_page_find_least(object, pi + n);
@@ -844,77 +845,39 @@ rescan:
 static int
 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags)
 {
-       int runlen;
-       int maxf;
-       int chkb;
-       int maxb;
-       int i, index;
-       vm_pindex_t pi;
-       vm_page_t maf[vm_pageout_page_count];
-       vm_page_t mab[vm_pageout_page_count];
-       vm_page_t ma[vm_pageout_page_count];
-       vm_page_t tp, p1;
+       vm_page_t ma[vm_pageout_page_count], p_first, tp;
+       int count, i, mreq, runlen;
 
        mtx_assert(&vm_page_queue_mtx, MA_OWNED);
-       pi = p->pindex;
-       maxf = 0;
-       for (i = 1, p1 = p; i < vm_pageout_page_count; i++) {
-               tp = vm_page_next(p1);
+
+       count = 1;
+       mreq = 0;
+
+       for (tp = p; count < vm_pageout_page_count; count++) {
+               tp = vm_page_next(tp);
                if (tp == NULL || tp->busy != 0 || (tp->oflags & VPO_BUSY) != 0)
                        break;
                vm_page_test_dirty(tp);
                if (tp->dirty == 0)
                        break;
-               maf[i - 1] = p1 = tp;
-               maxf++;
        }
 
-       maxb = 0;
-       chkb = vm_pageout_page_count -  maxf;
-       for (i = 1, p1 = p; i < chkb; i++) {
-               tp = vm_page_prev(p1);
+       for (p_first = p; count < vm_pageout_page_count; count++) {
+               tp = vm_page_prev(p_first);
                if (tp == NULL || tp->busy != 0 || (tp->oflags & VPO_BUSY) != 0)
                        break;
                vm_page_test_dirty(tp);
                if (tp->dirty == 0)
                        break;
-               mab[i - 1] = p1 = tp;
-               maxb++;
+               p_first = tp;
+               mreq++;
        }
 
-       for (i = 0; i < maxb; i++) {
-               index = (maxb - i) - 1;
-               ma[index] = mab[i];
-       }
-       ma[maxb] = p;
-       for (i = 0; i < maxf; i++) {
-               index = (maxb + i) + 1;
-               ma[index] = maf[i];
-       }
-       runlen = maxb + maxf + 1;
+       for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++)
+               ma[i] = tp;
 
-       vm_pageout_flush(ma, runlen, pagerflags);
-       for (i = 0; i < runlen; i++) {
-               if (ma[i]->dirty != 0) {
-                       KASSERT((ma[i]->flags & PG_WRITEABLE) == 0,
-       ("vm_object_page_collect_flush: page %p is not write protected",
-                           ma[i]));
-               }
-       }
-       for (i = 0; i < maxf; i++) {
-               if (ma[i + maxb + 1]->dirty != 0) {
-                       /*
-                        * maxf will end up being the actual number of pages
-                        * we wrote out contiguously, non-inclusive of the
-                        * first page.  We do not count look-behind pages.
-                        */
-                       if (maxf > i) {
-                               maxf = i;
-                               break;
-                       }
-               }
-       }
-       return (maxf + 1);
+       vm_pageout_flush(ma, count, pagerflags, mreq, &runlen);
+       return (runlen);
 }
 
 /*

Modified: stable/8/sys/vm/vm_pageout.c
==============================================================================
--- stable/8/sys/vm/vm_pageout.c        Fri Nov 26 14:50:42 2010        
(r215865)
+++ stable/8/sys/vm/vm_pageout.c        Fri Nov 26 15:30:02 2010        
(r215866)
@@ -391,7 +391,7 @@ more:
        /*
         * we allow reads during pageouts...
         */
-       return (vm_pageout_flush(&mc[page_base], pageout_count, 0));
+       return (vm_pageout_flush(&mc[page_base], pageout_count, 0, 0, NULL));
 }
 
 /*
@@ -402,14 +402,17 @@ more:
  *     reference count all in here rather then in the parent.  If we want
  *     the parent to do more sophisticated things we may have to change
  *     the ordering.
+ *
+ *     Returned runlen is the count of pages between mreq and first
+ *     page after mreq with status VM_PAGER_AGAIN.
  */
 int
-vm_pageout_flush(vm_page_t *mc, int count, int flags)
+vm_pageout_flush(vm_page_t *mc, int count, int flags, int mreq, int *prunlen)
 {
        vm_object_t object = mc[0]->object;
        int pageout_status[count];
        int numpagedout = 0;
-       int i;
+       int i, runlen;
 
        mtx_assert(&vm_page_queue_mtx, MA_OWNED);
        VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
@@ -435,6 +438,7 @@ vm_pageout_flush(vm_page_t *mc, int coun
 
        vm_pager_put_pages(object, mc, count, flags, pageout_status);
 
+       runlen = count - mreq;
        vm_page_lock_queues();
        for (i = 0; i < count; i++) {
                vm_page_t mt = mc[i];
@@ -465,6 +469,8 @@ vm_pageout_flush(vm_page_t *mc, int coun
                        vm_page_activate(mt);
                        break;
                case VM_PAGER_AGAIN:
+                       if (i >= mreq && i - mreq < runlen)
+                               runlen = i - mreq;
                        break;
                }
 
@@ -481,7 +487,9 @@ vm_pageout_flush(vm_page_t *mc, int coun
                                vm_page_try_to_cache(mt);
                }
        }
-       return numpagedout;
+       if (prunlen != NULL)
+               *prunlen = runlen;
+       return (numpagedout);
 }
 
 #if !defined(NO_SWAPPING)

Modified: stable/8/sys/vm/vm_pageout.h
==============================================================================
--- stable/8/sys/vm/vm_pageout.h        Fri Nov 26 14:50:42 2010        
(r215865)
+++ stable/8/sys/vm/vm_pageout.h        Fri Nov 26 15:30:02 2010        
(r215866)
@@ -102,7 +102,7 @@ extern void vm_waitpfault(void);
 
 #ifdef _KERNEL
 boolean_t vm_pageout_fallback_object_lock(vm_page_t, vm_page_t *);
-int vm_pageout_flush(vm_page_t *, int, int);
+int vm_pageout_flush(vm_page_t *, int, int, int, int *);
 void vm_pageout_oom(int shortage);
 #endif
 #endif /* _VM_VM_PAGEOUT_H_ */
_______________________________________________
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"

Reply via email to