Hi Linus and Rik,

The same analysis I did for __alloc_pages() applies to
__alloc_pages_limit(), namely it can be optimized by looking at the logic
of 'page == NULL'. In both cases, of course, I checked the assembly
listing to make sure that my patch didn't make a worse code. It was always
a few instructions shorter and therefore worth it. (I didn't check whether
gcc produced fewer branches, I assume he did, otherwise he would be
totally braindead...).

Regards,
Tigran

--- linux/mm/page_alloc.c       Sun Oct 15 20:40:38 2000
+++ work/mm/page_alloc.c        Mon Oct 16 22:39:13 2000
@@ -262,15 +262,17 @@
                }
 
                if (z->free_pages + z->inactive_clean_pages >= water_mark) {
-                       struct page *page = NULL;
+                       struct page *page;
                        /* If possible, reclaim a page directly. */
-                       if (direct_reclaim && z->free_pages < z->pages_min + 8)
+                       if (direct_reclaim && z->free_pages < z->pages_min + 8) {
                                page = reclaim_page(z);
-                       /* If that fails, fall back to rmqueue. */
-                       if (!page)
-                               page = rmqueue(z, order);
-                       if (page)
-                               return page;
+                               /* If that fails, fall back to rmqueue. */
+                               if (!page) {
+                                       page = rmqueue(z, order);
+                                       if (page)
+                                               return page;
+                               }
+                       }
                }
        }
 

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