From 1dbd0b24d25c42dc5f85932f9f94492dad873019 Mon Sep 17 00:00:00 2001
From: "Yichun Zhang (agentzh)" <agentzh@gmail.com>
Date: Tue, 6 May 2014 13:16:59 -0700
Subject: [PATCH] apply the slab_defrag patch to the nginx core by default.

---
 patches/nginx-1.7.0-slab_defrag.patch | 100 ++++++++++++++++++++++++++
 util/mirror-tarballs                  |   4 ++
 2 files changed, 104 insertions(+)
 create mode 100644 patches/nginx-1.7.0-slab_defrag.patch

diff --git a/patches/nginx-1.7.0-slab_defrag.patch b/patches/nginx-1.7.0-slab_defrag.patch
new file mode 100644
index 0000000..03f95be
--- /dev/null
+++ b/patches/nginx-1.7.0-slab_defrag.patch
@@ -0,0 +1,100 @@
+diff -r 7586e7b2dbe9 src/core/ngx_slab.c
+--- a/src/core/ngx_slab.c	Tue Feb 18 17:30:40 2014 +0400
++++ b/src/core/ngx_slab.c	Tue May 06 12:32:22 2014 -0700
+@@ -118,6 +118,7 @@
+     pool->pages->slab = pages;
+     pool->pages->next = &pool->free;
+     pool->pages->prev = (uintptr_t) &pool->free;
++    pool->pages->prev_slab = 0;
+ 
+     pool->start = (u_char *)
+                   ngx_align_ptr((uintptr_t) p + pages * sizeof(ngx_slab_page_t),
+@@ -628,6 +629,7 @@
+                 page[pages].slab = page->slab - pages;
+                 page[pages].next = page->next;
+                 page[pages].prev = page->prev;
++                page[pages].prev_slab = pages;
+ 
+                 p = (ngx_slab_page_t *) page->prev;
+                 p->next = &page[pages];
+@@ -651,6 +653,7 @@
+                 p->slab = NGX_SLAB_PAGE_BUSY;
+                 p->next = NULL;
+                 p->prev = NGX_SLAB_PAGE;
++                p->prev_slab = 0;
+                 p++;
+             }
+ 
+@@ -668,7 +671,7 @@
+ ngx_slab_free_pages(ngx_slab_pool_t *pool, ngx_slab_page_t *page,
+     ngx_uint_t pages)
+ {
+-    ngx_slab_page_t  *prev;
++    ngx_slab_page_t  *prev, *p;
+ 
+     page->slab = pages--;
+ 
+@@ -682,6 +685,52 @@
+         page->next->prev = page->prev;
+     }
+ 
++    /* try to merge the following free slab (if any) */
++
++    p = &page[page->slab];
++    if ((u_char *) p < pool->start
++        && !(p->slab & NGX_SLAB_PAGE_START)
++        && p->next != NULL
++        && (p->prev & NGX_SLAB_PAGE_MASK) == NGX_SLAB_PAGE)
++    {
++        page->slab += p->slab;
++
++        /* remove the following slab from the free list */
++
++        prev = (ngx_slab_page_t *) p->prev;
++        prev->next = p->next;
++        p->next->prev = p->prev;
++
++        ngx_memzero(p, sizeof(ngx_slab_page_t));
++
++        /* adjust prev_slab in the new following slab accordingly */
++        if ((u_char *) (p + p->slab) < pool->start) {
++            p[p->slab].prev_slab = page->slab;
++        }
++    }
++
++    if (page->prev_slab) {
++        /* try to merge the preceding free slab (if any) */
++
++        p = page - page->prev_slab;
++        if (!(p->slab & NGX_SLAB_PAGE_START)
++            && p->next != NULL
++            && (p->prev & NGX_SLAB_PAGE_MASK) == NGX_SLAB_PAGE)
++        {
++            p->slab += page->slab;
++
++            /* adjust prev_slab in the new following slab accordingly */
++            if ((u_char *) (p + p->slab) < pool->start) {
++                p[p->slab].prev_slab = p->slab;
++            }
++
++            ngx_memzero(page, sizeof(ngx_slab_page_t));
++
++            /* skip adding "page" to the free list */
++            return;
++        }
++    }
++
+     page->prev = (uintptr_t) &pool->free;
+     page->next = pool->free.next;
+ 
+diff -r 7586e7b2dbe9 src/core/ngx_slab.h
+--- a/src/core/ngx_slab.h	Tue Feb 18 17:30:40 2014 +0400
++++ b/src/core/ngx_slab.h	Tue May 06 12:32:22 2014 -0700
+@@ -19,6 +19,7 @@
+     uintptr_t         slab;
+     ngx_slab_page_t  *next;
+     uintptr_t         prev;
++    uintptr_t         prev_slab;
+ };
+ 
+ 
diff --git a/util/mirror-tarballs b/util/mirror-tarballs
index 193f3e2..f1d0c75 100755
--- a/util/mirror-tarballs
+++ b/util/mirror-tarballs
@@ -242,6 +242,10 @@ echo "$info_txt applying the setting_args_invalidates_uri patch for nginx $ver"
 patch -p1 < $root/patches/nginx-$ver-setting_args_invalidates_uri.patch || exit 1
 echo
 
+echo "$info_txt applying the slab_defrag patch for nginx"
+patch -p1 < $root/patches/nginx-$main_ver-slab_defrag.patch || exit 1
+echo
+
 rm -f *.patch || exit 1
 
 cd .. || exit 1