[PATCH] x86_64: Inclusion of ScaleMP vSMP architecture patches - vsmp_align

vSMP specific alignment patch to
1. Define INTERNODE_CACHE_SHIFT for vSMP
2. Use this for alignment of critical structures
3. Use INTERNODE_CACHE_SHIFT for ARCH_MIN_TASKALIGN,
   and let the slab align task_struct allocations to the internode cacheline size
4. Introduce and use ARCH_MIN_MMSTRUCT_ALIGN for mm_struct slab allocations.
Signed-off-by: NRavikiran Thirumalai <kiran@scalemp.com>
Signed-off-by: NShai Fultheim <shai@scalemp.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

include/asm-x86_64/cache.h

@@ -10,4 +10,16 @@
 #define L1_CACHE_SHIFT	(CONFIG_X86_L1_CACHE_SHIFT)
 #define L1_CACHE_BYTES	(1 << L1_CACHE_SHIFT)
 
+#ifdef CONFIG_X86_VSMP
+
+/* vSMP Internode cacheline shift */
+#define INTERNODE_CACHE_SHIFT (12)
+#ifdef CONFIG_SMP
+#define __cacheline_aligned_in_smp					\
+       __attribute__((__aligned__(1 << (INTERNODE_CACHE_SHIFT))))         \
+       __attribute__((__section__(".data.page_aligned")))
+#endif
+
+#endif
+
 #endif

include/asm-x86_64/processor.h

@@ -227,7 +227,13 @@ struct tss_struct {
 extern struct cpuinfo_x86 boot_cpu_data;
 DECLARE_PER_CPU(struct tss_struct,init_tss);
 
+#ifdef CONFIG_X86_VSMP
+#define ARCH_MIN_TASKALIGN	(1 << INTERNODE_CACHE_SHIFT)
+#define ARCH_MIN_MMSTRUCT_ALIGN	(1 << INTERNODE_CACHE_SHIFT)
+#else
 #define ARCH_MIN_TASKALIGN	16
+#define ARCH_MIN_MMSTRUCT_ALIGN	0
+#endif
 
 struct thread_struct {
 	unsigned long	rsp0;

kernel/fork.c

@@ -1298,6 +1298,10 @@ long do_fork(unsigned long clone_flags,
 	return pid;
 }
 
+#ifndef ARCH_MIN_MMSTRUCT_ALIGN
+#define ARCH_MIN_MMSTRUCT_ALIGN 0
+#endif
+
 void __init proc_caches_init(void)
 {
 	sighand_cachep = kmem_cache_create("sighand_cache",
@@ -1316,6 +1320,6 @@ void __init proc_caches_init(void)
 			sizeof(struct vm_area_struct), 0,
 			SLAB_PANIC, NULL, NULL);
 	mm_cachep = kmem_cache_create("mm_struct",
-			sizeof(struct mm_struct), 0,
+			sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
 			SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
 }