[PATCH] memory page alloc minor cleanups

- s/freeliest/freelist/ spelling fix

- Check for NULL *z zone seems useless - even if it could happen, so
  what?  Perhaps we should have a check later on if we are faced with an
  allocation request that is not allowed to fail - shouldn't that be a
  serious kernel error, passing an empty zonelist with a mandate to not
  fail?

- Initializing 'z' to zonelist->zones can wait until after the first
  get_page_from_freelist() fails; we only use 'z' in the wakeup_kswapd()
  loop, so let's initialize 'z' there, in a 'for' loop.  Seems clearer.

- Remove superfluous braces around a break

- Fix a couple errant spaces

- Adjust indentation on the cpuset_zone_allowed() check, to match the
  lines just before it -- seems easier to read in this case.

- Add another set of braces to the zone_watermark_ok logic

From: Paul Jackson <pj@sgi.com>

  Backout one item from a previous "memory page_alloc minor cleanups" patch.
   Until and unless we are certain that no one can ever pass an empty zonelist
  to __alloc_pages(), this check for an empty zonelist (or some BUG
  equivalent) is essential.  The code in get_page_from_freelist() blow ups if
  passed an empty zonelist.

Signed-off-by: Paul Jackson <pj@sgi.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index aa6fcc7ca66f1f8bc976b5798039c3a0672d09eb..08360aa111f97f60d45c23542f77bfa2e06b718d 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -486,7 +486,7 @@ static void free_one_page(struct zone *zone, struct page *page, int order)
        spin_lock(&zone->lock);
        zone->all_unreclaimable = 0;
        zone->pages_scanned = 0;
-       __free_one_page(page, zone ,order);
+       __free_one_page(page, zone, order);
        spin_unlock(&zone->lock);
 }
 
@@ -926,7 +926,7 @@ int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 }
 
 /*
- * get_page_from_freeliest goes through the zonelist trying to allocate
+ * get_page_from_freelist goes through the zonelist trying to allocate
  * a page.
  */
 static struct page *
@@ -948,8 +948,8 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order,
                        zone->zone_pgdat != zonelist->zones[0]->zone_pgdat))
                                break;
                if ((alloc_flags & ALLOC_CPUSET) &&
-                               !cpuset_zone_allowed(zone, gfp_mask))
-                       continue;
+                       !cpuset_zone_allowed(zone, gfp_mask))
+                               continue;
 
                if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
                        unsigned long mark;
@@ -959,17 +959,18 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order,
                                mark = zone->pages_low;
                        else
                                mark = zone->pages_high;
-                       if (!zone_watermark_ok(zone , order, mark,
-                                   classzone_idx, alloc_flags))
+                       if (!zone_watermark_ok(zone, order, mark,
+                                   classzone_idx, alloc_flags)) {
                                if (!zone_reclaim_mode ||
                                    !zone_reclaim(zone, gfp_mask, order))
                                        continue;
+                       }
                }
 
                page = buffered_rmqueue(zonelist, zone, order, gfp_mask);
-               if (page) {
+               if (page)
                        break;
-               }
+
        } while (*(++z) != NULL);
        return page;
 }
@@ -1005,9 +1006,8 @@ restart:
        if (page)
                goto got_pg;
 
-       do {
+       for (z = zonelist->zones; *z; z++)
                wakeup_kswapd(*z, order);
-       } while (*(++z));
 
        /*
         * OK, we're below the kswapd watermark and have kicked background