In article <m16BKdv-000CgdC@Wasteland> you wrote:
> First patch, please explain what I did wrong :)
Nothing, but can be improved further.
One can use that function in kmalloc() and then optimize the function using
a binary search.
--- slab.c 2001/09/21 16:28:50 1.27
+++ slab.c 2001/12/05 07:51:58
@@ -1533,14 +1533,13 @@
*/
void * kmalloc (size_t size, int flags)
{
- cache_sizes_t *csizep = cache_sizes;
+ kmem_cache_t *cp;
+
+ cp = kmem_find_general_cachep(size, flags);
+
+ if (cp)
+ return __kmem_cache_alloc(cp, flags);
- for (; csizep->cs_size; csizep++) {
- if (size > csizep->cs_size)
- continue;
- return __kmem_cache_alloc(flags & GFP_DMA ?
- csizep->cs_dmacachep : csizep->cs_cachep, flags);
- }
return NULL;
}
the patch for having the binary search will look something like:
From: Momchil Velikov <velco@fadata.bg>
@@ -1589,18 +1583,66 @@ void kfree (const void *objp)
kmem_cache_t * kmem_find_general_cachep (size_t size, int gfpflags)
{
- cache_sizes_t *csizep = cache_sizes;
+ int idx;
- /* This function could be moved to the header file, and
- * made inline so consumers can quickly determine what
- * cache pointer they require.
- */
- for ( ; csizep->cs_size; csizep++) {
- if (size > csizep->cs_size)
- continue;
+ switch (size) {
+#if PAGE_SIZE == 4096
+ case 0 ... 32:
+ idx = 0;
+ break;
+ case 33 ... 64:
+ idx = 1;
+ break;
+#else
+ case 0 ... 64:
+ idx = 1;
+ break;
+#endif
+ case 65 ... 128:
+ idx = 2;
+ break;
+ case 129 ... 256:
+ idx = 3;
+ break;
+ case 257 ...512:
+ idx = 4;
+ break;
+ case 513 ... 1024:
+ idx = 5;
+ break;
+ case 1025 ... 2048:
+ idx = 6;
+ break;
+ case 2049 ... 4096:
+ idx = 7;
+ break;
+ case 4097 ... 8192:
+ idx = 8;
+ break;
+ case 8193 ... 16384:
+ idx = 9;
+ break;
+ case 16385 ... 32768:
+ idx = 10;
+ break;
+ case 32769 ... 65536:
+ idx = 11;
+ break;
+ case 65537 ... 131072:
+ idx = 12;
+ break;
+ default:
+ idx = -1;
break;
}
- return (gfpflags & GFP_DMA) ? csizep->cs_dmacachep : csizep->cs_cachep;
+
+ if (idx == -1)
+ return NULL;
+
+#if PAGE_SIZE != 4096
+ idx = idx - 1;
+#endif
+ return (gfpflags & GFP_DMA) ? cache_sizes [idx].cs_dmacachep : cache_sizes [idx].cs_cachep;
}
#ifdef CONFIG_SMP
I have not tested yet if the "idx -1" is optimized good, or if it is better
to have assigend idx the values depending on the #define. But otherwise it
should work well.
Greetings
Bernd
-
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This archive was generated by hypermail 2b29 : Fri Dec 07 2001 - 21:00:27 EST