]> err.no Git - linux-2.6/commitdiff
[PATCH] mm: __alloc_pages cleanup
authorRohit Seth <rohit.seth@intel.com>
Mon, 14 Nov 2005 00:06:43 +0000 (16:06 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Mon, 14 Nov 2005 02:14:12 +0000 (18:14 -0800)
Clean up of __alloc_pages.

Restoration of previous behaviour, plus further cleanups by introducing an
'alloc_flags', removing the last of should_reclaim_zone.

Signed-off-by: Rohit Seth <rohit.seth@intel.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
include/linux/mmzone.h
mm/page_alloc.c
mm/vmscan.c

index f5fa3082fd6a56c628730c67873429f64f8d9cbb..6cfb114a0c34444756bda25bdc362dd673585dd2 100644 (file)
@@ -329,7 +329,7 @@ void get_zone_counts(unsigned long *active, unsigned long *inactive,
 void build_all_zonelists(void);
 void wakeup_kswapd(struct zone *zone, int order);
 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
-               int alloc_type, int can_try_harder, gfp_t gfp_high);
+               int classzone_idx, int alloc_flags);
 
 #ifdef CONFIG_HAVE_MEMORY_PRESENT
 void memory_present(int nid, unsigned long start, unsigned long end);
index b37dc0f78d077834a8839f92ca0ad93f4f49c971..845b91749a423b49e457e44db6e5b279a85e1f69 100644 (file)
@@ -732,9 +732,7 @@ buffered_rmqueue(struct zone *zone, int order, gfp_t gfp_flags)
                }
                local_irq_restore(flags);
                put_cpu();
-       }
-
-       if (page == NULL) {
+       } else {
                spin_lock_irqsave(&zone->lock, flags);
                page = __rmqueue(zone, order);
                spin_unlock_irqrestore(&zone->lock, flags);
@@ -754,20 +752,25 @@ buffered_rmqueue(struct zone *zone, int order, gfp_t gfp_flags)
        return page;
 }
 
+#define ALLOC_NO_WATERMARKS    0x01 /* don't check watermarks at all */
+#define ALLOC_HARDER           0x02 /* try to alloc harder */
+#define ALLOC_HIGH             0x04 /* __GFP_HIGH set */
+#define ALLOC_CPUSET           0x08 /* check for correct cpuset */
+
 /*
  * Return 1 if free pages are above 'mark'. This takes into account the order
  * of the allocation.
  */
 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
-                     int classzone_idx, int can_try_harder, gfp_t gfp_high)
+                     int classzone_idx, int alloc_flags)
 {
        /* free_pages my go negative - that's OK */
        long min = mark, free_pages = z->free_pages - (1 << order) + 1;
        int o;
 
-       if (gfp_high)
+       if (alloc_flags & ALLOC_HIGH)
                min -= min / 2;
-       if (can_try_harder)
+       if (alloc_flags & ALLOC_HARDER)
                min -= min / 4;
 
        if (free_pages <= min + z->lowmem_reserve[classzone_idx])
@@ -785,14 +788,40 @@ int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
        return 1;
 }
 
-static inline int
-should_reclaim_zone(struct zone *z, gfp_t gfp_mask)
+/*
+ * get_page_from_freeliest goes through the zonelist trying to allocate
+ * a page.
+ */
+static struct page *
+get_page_from_freelist(gfp_t gfp_mask, unsigned int order,
+               struct zonelist *zonelist, int alloc_flags)
 {
-       if (!z->reclaim_pages)
-               return 0;
-       if (gfp_mask & __GFP_NORECLAIM)
-               return 0;
-       return 1;
+       struct zone **z = zonelist->zones;
+       struct page *page = NULL;
+       int classzone_idx = zone_idx(*z);
+
+       /*
+        * Go through the zonelist once, looking for a zone with enough free.
+        * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
+        */
+       do {
+               if ((alloc_flags & ALLOC_CPUSET) &&
+                               !cpuset_zone_allowed(*z, gfp_mask))
+                       continue;
+
+               if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
+                       if (!zone_watermark_ok(*z, order, (*z)->pages_low,
+                                   classzone_idx, alloc_flags))
+                               continue;
+               }
+
+               page = buffered_rmqueue(*z, order, gfp_mask);
+               if (page) {
+                       zone_statistics(zonelist, *z);
+                       break;
+               }
+       } while (*(++z) != NULL);
+       return page;
 }
 
 /*
@@ -803,92 +832,60 @@ __alloc_pages(gfp_t gfp_mask, unsigned int order,
                struct zonelist *zonelist)
 {
        const gfp_t wait = gfp_mask & __GFP_WAIT;
-       struct zone **zones, *z;
+       struct zone **z;
        struct page *page;
        struct reclaim_state reclaim_state;
        struct task_struct *p = current;
-       int i;
-       int classzone_idx;
        int do_retry;
-       int can_try_harder;
+       int alloc_flags;
        int did_some_progress;
 
        might_sleep_if(wait);
 
-       /*
-        * The caller may dip into page reserves a bit more if the caller
-        * cannot run direct reclaim, or is the caller has realtime scheduling
-        * policy
-        */
-       can_try_harder = (unlikely(rt_task(p)) && !in_interrupt()) || !wait;
-
-       zones = zonelist->zones;  /* the list of zones suitable for gfp_mask */
+       z = zonelist->zones;  /* the list of zones suitable for gfp_mask */
 
-       if (unlikely(zones[0] == NULL)) {
+       if (unlikely(*z == NULL)) {
                /* Should this ever happen?? */
                return NULL;
        }
+restart:
+       page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
+                               zonelist, ALLOC_CPUSET);
+       if (page)
+               goto got_pg;
 
-       classzone_idx = zone_idx(zones[0]);
+       do
+               wakeup_kswapd(*z, order);
+       while (*(++z));
 
-restart:
        /*
-        * Go through the zonelist once, looking for a zone with enough free.
-        * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
+        * OK, we're below the kswapd watermark and have kicked background
+        * reclaim. Now things get more complex, so set up alloc_flags according
+        * to how we want to proceed.
+        *
+        * The caller may dip into page reserves a bit more if the caller
+        * cannot run direct reclaim, or if the caller has realtime scheduling
+        * policy.
         */
-       for (i = 0; (z = zones[i]) != NULL; i++) {
-               int do_reclaim = should_reclaim_zone(z, gfp_mask);
-
-               if (!cpuset_zone_allowed(z, __GFP_HARDWALL))
-                       continue;
-
-               /*
-                * If the zone is to attempt early page reclaim then this loop
-                * will try to reclaim pages and check the watermark a second
-                * time before giving up and falling back to the next zone.
-                */
-zone_reclaim_retry:
-               if (!zone_watermark_ok(z, order, z->pages_low,
-                                      classzone_idx, 0, 0)) {
-                       if (!do_reclaim)
-                               continue;
-                       else {
-                               zone_reclaim(z, gfp_mask, order);
-                               /* Only try reclaim once */
-                               do_reclaim = 0;
-                               goto zone_reclaim_retry;
-                       }
-               }
-
-               page = buffered_rmqueue(z, order, gfp_mask);
-               if (page)
-                       goto got_pg;
-       }
-
-       for (i = 0; (z = zones[i]) != NULL; i++)
-               wakeup_kswapd(z, order);
+       alloc_flags = 0;
+       if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
+               alloc_flags |= ALLOC_HARDER;
+       if (gfp_mask & __GFP_HIGH)
+               alloc_flags |= ALLOC_HIGH;
+       if (wait)
+               alloc_flags |= ALLOC_CPUSET;
 
        /*
         * Go through the zonelist again. Let __GFP_HIGH and allocations
-        * coming from realtime tasks to go deeper into reserves
+        * coming from realtime tasks go deeper into reserves.
         *
         * This is the last chance, in general, before the goto nopage.
         * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
         * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
         */
-       for (i = 0; (z = zones[i]) != NULL; i++) {
-               if (!zone_watermark_ok(z, order, z->pages_min,
-                                      classzone_idx, can_try_harder,
-                                      gfp_mask & __GFP_HIGH))
-                       continue;
-
-               if (wait && !cpuset_zone_allowed(z, gfp_mask))
-                       continue;
-
-               page = buffered_rmqueue(z, order, gfp_mask);
-               if (page)
-                       goto got_pg;
-       }
+       page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags);
+       if (page)
+               goto got_pg;
 
        /* This allocation should allow future memory freeing. */
 
@@ -897,13 +894,10 @@ zone_reclaim_retry:
                if (!(gfp_mask & __GFP_NOMEMALLOC)) {
 nofail_alloc:
                        /* go through the zonelist yet again, ignoring mins */
-                       for (i = 0; (z = zones[i]) != NULL; i++) {
-                               if (!cpuset_zone_allowed(z, gfp_mask))
-                                       continue;
-                               page = buffered_rmqueue(z, order, gfp_mask);
-                               if (page)
-                                       goto got_pg;
-                       }
+                       page = get_page_from_freelist(gfp_mask, order,
+                               zonelist, ALLOC_NO_WATERMARKS|ALLOC_CPUSET);
+                       if (page)
+                               goto got_pg;
                        if (gfp_mask & __GFP_NOFAIL) {
                                blk_congestion_wait(WRITE, HZ/50);
                                goto nofail_alloc;
@@ -924,7 +918,7 @@ rebalance:
        reclaim_state.reclaimed_slab = 0;
        p->reclaim_state = &reclaim_state;
 
-       did_some_progress = try_to_free_pages(zones, gfp_mask);
+       did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask);
 
        p->reclaim_state = NULL;
        p->flags &= ~PF_MEMALLOC;
@@ -932,19 +926,10 @@ rebalance:
        cond_resched();
 
        if (likely(did_some_progress)) {
-               for (i = 0; (z = zones[i]) != NULL; i++) {
-                       if (!zone_watermark_ok(z, order, z->pages_min,
-                                              classzone_idx, can_try_harder,
-                                              gfp_mask & __GFP_HIGH))
-                               continue;
-
-                       if (!cpuset_zone_allowed(z, gfp_mask))
-                               continue;
-
-                       page = buffered_rmqueue(z, order, gfp_mask);
-                       if (page)
-                               goto got_pg;
-               }
+               page = get_page_from_freelist(gfp_mask, order,
+                                               zonelist, alloc_flags);
+               if (page)
+                       goto got_pg;
        } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
                /*
                 * Go through the zonelist yet one more time, keep
@@ -952,18 +937,10 @@ rebalance:
                 * a parallel oom killing, we must fail if we're still
                 * under heavy pressure.
                 */
-               for (i = 0; (z = zones[i]) != NULL; i++) {
-                       if (!zone_watermark_ok(z, order, z->pages_high,
-                                              classzone_idx, 0, 0))
-                               continue;
-
-                       if (!cpuset_zone_allowed(z, __GFP_HARDWALL))
-                               continue;
-
-                       page = buffered_rmqueue(z, order, gfp_mask);
-                       if (page)
-                               goto got_pg;
-               }
+               page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
+                                               zonelist, ALLOC_CPUSET);
+               if (page)
+                       goto got_pg;
 
                out_of_memory(gfp_mask, order);
                goto restart;
@@ -996,9 +973,7 @@ nopage:
                dump_stack();
                show_mem();
        }
-       return NULL;
 got_pg:
-       zone_statistics(zonelist, z);
        return page;
 }
 
index 135bf8ca96ee60ac78783caac94fa30f2bfabfc8..28130541270f5ad35b3e18ac878b349c61c6e01f 100644 (file)
@@ -1074,7 +1074,7 @@ loop_again:
                                        continue;
 
                                if (!zone_watermark_ok(zone, order,
-                                               zone->pages_high, 0, 0, 0)) {
+                                               zone->pages_high, 0, 0)) {
                                        end_zone = i;
                                        goto scan;
                                }
@@ -1111,7 +1111,7 @@ scan:
 
                        if (nr_pages == 0) {    /* Not software suspend */
                                if (!zone_watermark_ok(zone, order,
-                                               zone->pages_high, end_zone, 0, 0))
+                                               zone->pages_high, end_zone, 0))
                                        all_zones_ok = 0;
                        }
                        zone->temp_priority = priority;
@@ -1259,7 +1259,7 @@ void wakeup_kswapd(struct zone *zone, int order)
                return;
 
        pgdat = zone->zone_pgdat;
-       if (zone_watermark_ok(zone, order, zone->pages_low, 0, 0, 0))
+       if (zone_watermark_ok(zone, order, zone->pages_low, 0, 0))
                return;
        if (pgdat->kswapd_max_order < order)
                pgdat->kswapd_max_order = order;