x86: tsc prevent time going backwards

[sfrench/cifs-2.6.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 45711585684ec74c01f7b93ae28a8d8b4f62bfb9..4046434046e68b0a45864c019a095fab088420ee 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -70,13 +70,6 @@ struct scan_control {
 
        int order;
 
-       /*
-        * Pages that have (or should have) IO pending.  If we run into
-        * a lot of these, we're better off waiting a little for IO to
-        * finish rather than scanning more pages in the VM.
-        */
-       int nr_io_pages;
-
        /* Which cgroup do we reclaim from */
        struct mem_cgroup *mem_cgroup;
 
@@ -512,10 +505,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                         */
                        if (sync_writeback == PAGEOUT_IO_SYNC && may_enter_fs)
                                wait_on_page_writeback(page);
-                       else {
-                               sc->nr_io_pages++;
+                       else
                                goto keep_locked;
-                       }
                }
 
                referenced = page_referenced(page, 1, sc->mem_cgroup);
@@ -554,10 +545,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                if (PageDirty(page)) {
                        if (sc->order <= PAGE_ALLOC_COSTLY_ORDER && referenced)
                                goto keep_locked;
-                       if (!may_enter_fs) {
-                               sc->nr_io_pages++;
+                       if (!may_enter_fs)
                                goto keep_locked;
-                       }
                        if (!sc->may_writepage)
                                goto keep_locked;
 
@@ -568,10 +557,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                        case PAGE_ACTIVATE:
                                goto activate_locked;
                        case PAGE_SUCCESS:
-                               if (PageWriteback(page) || PageDirty(page)) {
-                                       sc->nr_io_pages++;
+                               if (PageWriteback(page) || PageDirty(page))
                                        goto keep;
-                               }
                                /*
                                 * A synchronous write - probably a ramdisk.  Go
                                 * ahead and try to reclaim the page.
@@ -1344,7 +1331,6 @@ static unsigned long do_try_to_free_pages(struct zone **zones, gfp_t gfp_mask,
 
        for (priority = DEF_PRIORITY; priority >= 0; priority--) {
                sc->nr_scanned = 0;
-               sc->nr_io_pages = 0;
                if (!priority)
                        disable_swap_token();
                nr_reclaimed += shrink_zones(priority, zones, sc);
@@ -1379,8 +1365,7 @@ static unsigned long do_try_to_free_pages(struct zone **zones, gfp_t gfp_mask,
                }
 
                /* Take a nap, wait for some writeback to complete */
-               if (sc->nr_scanned && priority < DEF_PRIORITY - 2 &&
-                               sc->nr_io_pages > sc->swap_cluster_max)
+               if (sc->nr_scanned && priority < DEF_PRIORITY - 2)
                        congestion_wait(WRITE, HZ/10);
        }
        /* top priority shrink_caches still had more to do? don't OOM, then */
@@ -1514,7 +1499,6 @@ loop_again:
                if (!priority)
                        disable_swap_token();
 
-               sc.nr_io_pages = 0;
                all_zones_ok = 1;
 
                /*
@@ -1607,8 +1591,7 @@ loop_again:
                 * OK, kswapd is getting into trouble.  Take a nap, then take
                 * another pass across the zones.
                 */
-               if (total_scanned && priority < DEF_PRIORITY - 2 &&
-                                       sc.nr_io_pages > sc.swap_cluster_max)
+               if (total_scanned && priority < DEF_PRIORITY - 2)
                        congestion_wait(WRITE, HZ/10);
 
                /*