Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=4b356be019d0c28f67af02809df7072c1c8f7d32
Commit:     4b356be019d0c28f67af02809df7072c1c8f7d32
Parent:     8dab5241d06bfc9ee141ea78c56cde5070d7460d
Author:     Christoph Lameter <[EMAIL PROTECTED]>
AuthorDate: Sat Jun 16 10:16:13 2007 -0700
Committer:  Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Sat Jun 16 13:16:16 2007 -0700

    SLUB: minimum alignment fixes
    
    If ARCH_KMALLOC_MINALIGN is set to a value greater than 8 (SLUBs smallest
    kmalloc cache) then SLUB may generate duplicate slabs in sysfs (yes again)
    because the object size is padded to reach ARCH_KMALLOC_MINALIGN.  Thus the
    size of the small slabs is all the same.
    
    No arch sets ARCH_KMALLOC_MINALIGN larger than 8 though except mips which
    for some reason wants a 128 byte alignment.
    
    This patch increases the size of the smallest cache if
    ARCH_KMALLOC_MINALIGN is greater than 8.  In that case more and more of the
    smallest caches are disabled.
    
    If we do that then the count of the active general caches that is displayed
    on boot is not correct anymore since we may skip elements of the kmalloc
    array.  So count them separately.
    
    This approach was tested by Havard yesterday.
    
    Signed-off-by: Christoph Lameter <[EMAIL PROTECTED]>
    Cc: Haavard Skinnemoen <[EMAIL PROTECTED]>
    Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
    Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
 include/linux/slub_def.h |   13 +++++++++++--
 mm/slub.c                |   20 +++++++++++++++-----
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index a0ad374..6207a3d 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -28,7 +28,7 @@ struct kmem_cache {
        int size;               /* The size of an object including meta data */
        int objsize;            /* The size of an object without meta data */
        int offset;             /* Free pointer offset. */
-       unsigned int order;
+       int order;
 
        /*
         * Avoid an extra cache line for UP, SMP and for the node local to
@@ -56,7 +56,13 @@ struct kmem_cache {
 /*
  * Kmalloc subsystem.
  */
-#define KMALLOC_SHIFT_LOW 3
+#if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
+#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
+#else
+#define KMALLOC_MIN_SIZE 8
+#endif
+
+#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
 
 /*
  * We keep the general caches in an array of slab caches that are used for
@@ -76,6 +82,9 @@ static inline int kmalloc_index(size_t size)
        if (size > KMALLOC_MAX_SIZE)
                return -1;
 
+       if (size <= KMALLOC_MIN_SIZE)
+               return KMALLOC_SHIFT_LOW;
+
        if (size > 64 && size <= 96)
                return 1;
        if (size > 128 && size <= 192)
diff --git a/mm/slub.c b/mm/slub.c
index 2a1338c..fa28b16 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2436,6 +2436,7 @@ EXPORT_SYMBOL(krealloc);
 void __init kmem_cache_init(void)
 {
        int i;
+       int caches = 0;
 
 #ifdef CONFIG_NUMA
        /*
@@ -2446,20 +2447,29 @@ void __init kmem_cache_init(void)
        create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node",
                sizeof(struct kmem_cache_node), GFP_KERNEL);
        kmalloc_caches[0].refcount = -1;
+       caches++;
 #endif
 
        /* Able to allocate the per node structures */
        slab_state = PARTIAL;
 
        /* Caches that are not of the two-to-the-power-of size */
-       create_kmalloc_cache(&kmalloc_caches[1],
+       if (KMALLOC_MIN_SIZE <= 64) {
+               create_kmalloc_cache(&kmalloc_caches[1],
                                "kmalloc-96", 96, GFP_KERNEL);
-       create_kmalloc_cache(&kmalloc_caches[2],
+               caches++;
+       }
+       if (KMALLOC_MIN_SIZE <= 128) {
+               create_kmalloc_cache(&kmalloc_caches[2],
                                "kmalloc-192", 192, GFP_KERNEL);
+               caches++;
+       }
 
-       for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
+       for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
                create_kmalloc_cache(&kmalloc_caches[i],
                        "kmalloc", 1 << i, GFP_KERNEL);
+               caches++;
+       }
 
        slab_state = UP;
 
@@ -2476,8 +2486,8 @@ void __init kmem_cache_init(void)
                                nr_cpu_ids * sizeof(struct page *);
 
        printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, 
MinObjects=%d,"
-               " Processors=%d, Nodes=%d\n",
-               KMALLOC_SHIFT_HIGH, cache_line_size(),
+               " CPUs=%d, Nodes=%d\n",
+               caches, cache_line_size(),
                slub_min_order, slub_max_order, slub_min_objects,
                nr_cpu_ids, nr_node_ids);
 }
-
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