aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/cache.h
diff options
context:
space:
mode:
authorRavikiran G Thirumalai <kiran@scalex86.org>2006-01-08 04:01:27 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-08 23:13:38 -0500
commit22fc6eccbf4ce4eb6265e6ada7b50a7b9cc57d05 (patch)
tree3887dc6f1eeb658d773be037971b98d6f5fb3dd7 /include/linux/cache.h
parent6d524aed1f50b2b1d5b4ad5a4e2fe3f38106d0a6 (diff)
[PATCH] Change maxaligned_in_smp alignemnt macros to internodealigned_in_smp macros
____cacheline_maxaligned_in_smp is currently used to align critical structures and avoid false sharing. It uses per-arch L1_CACHE_SHIFT_MAX and people find L1_CACHE_SHIFT_MAX useless. However, we have been using ____cacheline_maxaligned_in_smp to align structures on the internode cacheline size. As per Andi's suggestion, following patch kills ____cacheline_maxaligned_in_smp and introduces INTERNODE_CACHE_SHIFT, which defaults to L1_CACHE_SHIFT for all arches. Arches needing L3/Internode cacheline alignment can define INTERNODE_CACHE_SHIFT in the arch asm/cache.h. Patch replaces ____cacheline_maxaligned_in_smp with ____cacheline_internodealigned_in_smp With this patch, L1_CACHE_SHIFT_MAX can be killed Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/cache.h')
-rw-r--r--include/linux/cache.h17
1 files changed, 13 insertions, 4 deletions
diff --git a/include/linux/cache.h b/include/linux/cache.h
index 0b7ecf3af78a..ffe52210fc4f 100644
--- a/include/linux/cache.h
+++ b/include/linux/cache.h
@@ -45,12 +45,21 @@
45#endif /* CONFIG_SMP */ 45#endif /* CONFIG_SMP */
46#endif 46#endif
47 47
48#if !defined(____cacheline_maxaligned_in_smp) 48/*
49 * The maximum alignment needed for some critical structures
50 * These could be inter-node cacheline sizes/L3 cacheline
51 * size etc. Define this in asm/cache.h for your arch
52 */
53#ifndef INTERNODE_CACHE_SHIFT
54#define INTERNODE_CACHE_SHIFT L1_CACHE_SHIFT
55#endif
56
57#if !defined(____cacheline_internodealigned_in_smp)
49#if defined(CONFIG_SMP) 58#if defined(CONFIG_SMP)
50#define ____cacheline_maxaligned_in_smp \ 59#define ____cacheline_internodealigned_in_smp \
51 __attribute__((__aligned__(1 << (L1_CACHE_SHIFT_MAX)))) 60 __attribute__((__aligned__(1 << (INTERNODE_CACHE_SHIFT))))
52#else 61#else
53#define ____cacheline_maxaligned_in_smp 62#define ____cacheline_internodealigned_in_smp
54#endif 63#endif
55#endif 64#endif
56 65