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author | Ravikiran G Thirumalai <kiran@scalex86.org> | 2006-01-08 01:01:27 -0800 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-08 20:13:38 -0800 |
commit | 22fc6eccbf4ce4eb6265e6ada7b50a7b9cc57d05 (patch) | |
tree | 3887dc6f1eeb658d773be037971b98d6f5fb3dd7 | |
parent | 6d524aed1f50b2b1d5b4ad5a4e2fe3f38106d0a6 (diff) | |
download | kernel_samsung_smdk4412-22fc6eccbf4ce4eb6265e6ada7b50a7b9cc57d05.tar.gz kernel_samsung_smdk4412-22fc6eccbf4ce4eb6265e6ada7b50a7b9cc57d05.tar.bz2 kernel_samsung_smdk4412-22fc6eccbf4ce4eb6265e6ada7b50a7b9cc57d05.zip |
[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>
-rw-r--r-- | arch/i386/kernel/init_task.c | 2 | ||||
-rw-r--r-- | arch/i386/kernel/irq.c | 2 | ||||
-rw-r--r-- | arch/x86_64/kernel/init_task.c | 2 | ||||
-rw-r--r-- | include/linux/cache.h | 17 | ||||
-rw-r--r-- | include/linux/ide.h | 2 | ||||
-rw-r--r-- | include/linux/mmzone.h | 4 | ||||
-rw-r--r-- | include/linux/rcupdate.h | 2 | ||||
-rw-r--r-- | kernel/rcupdate.c | 4 | ||||
-rw-r--r-- | mm/sparse.c | 4 |
9 files changed, 24 insertions, 15 deletions
diff --git a/arch/i386/kernel/init_task.c b/arch/i386/kernel/init_task.c index 9caa8e8db80..cff95d10a4d 100644 --- a/arch/i386/kernel/init_task.c +++ b/arch/i386/kernel/init_task.c @@ -42,5 +42,5 @@ EXPORT_SYMBOL(init_task); * per-CPU TSS segments. Threads are completely 'soft' on Linux, * no more per-task TSS's. */ -DEFINE_PER_CPU(struct tss_struct, init_tss) ____cacheline_maxaligned_in_smp = INIT_TSS; +DEFINE_PER_CPU(struct tss_struct, init_tss) ____cacheline_internodealigned_in_smp = INIT_TSS; diff --git a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c index 1a201a93286..f3a9c78c4a2 100644 --- a/arch/i386/kernel/irq.c +++ b/arch/i386/kernel/irq.c @@ -19,7 +19,7 @@ #include <linux/cpu.h> #include <linux/delay.h> -DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_maxaligned_in_smp; +DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_internodealigned_in_smp; EXPORT_PER_CPU_SYMBOL(irq_stat); #ifndef CONFIG_X86_LOCAL_APIC diff --git a/arch/x86_64/kernel/init_task.c b/arch/x86_64/kernel/init_task.c index e0ba5c1043f..ce31d904d60 100644 --- a/arch/x86_64/kernel/init_task.c +++ b/arch/x86_64/kernel/init_task.c @@ -44,6 +44,6 @@ EXPORT_SYMBOL(init_task); * section. Since TSS's are completely CPU-local, we want them * on exact cacheline boundaries, to eliminate cacheline ping-pong. */ -DEFINE_PER_CPU(struct tss_struct, init_tss) ____cacheline_maxaligned_in_smp = INIT_TSS; +DEFINE_PER_CPU(struct tss_struct, init_tss) ____cacheline_internodealigned_in_smp = INIT_TSS; #define ALIGN_TO_4K __attribute__((section(".data.init_task"))) diff --git a/include/linux/cache.h b/include/linux/cache.h index 0b7ecf3af78..ffe52210fc4 100644 --- a/include/linux/cache.h +++ b/include/linux/cache.h @@ -45,12 +45,21 @@ #endif /* CONFIG_SMP */ #endif -#if !defined(____cacheline_maxaligned_in_smp) +/* + * The maximum alignment needed for some critical structures + * These could be inter-node cacheline sizes/L3 cacheline + * size etc. Define this in asm/cache.h for your arch + */ +#ifndef INTERNODE_CACHE_SHIFT +#define INTERNODE_CACHE_SHIFT L1_CACHE_SHIFT +#endif + +#if !defined(____cacheline_internodealigned_in_smp) #if defined(CONFIG_SMP) -#define ____cacheline_maxaligned_in_smp \ - __attribute__((__aligned__(1 << (L1_CACHE_SHIFT_MAX)))) +#define ____cacheline_internodealigned_in_smp \ + __attribute__((__aligned__(1 << (INTERNODE_CACHE_SHIFT)))) #else -#define ____cacheline_maxaligned_in_smp +#define ____cacheline_internodealigned_in_smp #endif #endif diff --git a/include/linux/ide.h b/include/linux/ide.h index 7b6a6a58e46..4dd6694963c 100644 --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -801,7 +801,7 @@ typedef struct hwif_s { unsigned dma; void (*led_act)(void *data, int rw); -} ____cacheline_maxaligned_in_smp ide_hwif_t; +} ____cacheline_internodealigned_in_smp ide_hwif_t; /* * internal ide interrupt handler type diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 2a89c132ba9..7e4ae6ab197 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -38,7 +38,7 @@ struct pglist_data; #if defined(CONFIG_SMP) struct zone_padding { char x[0]; -} ____cacheline_maxaligned_in_smp; +} ____cacheline_internodealigned_in_smp; #define ZONE_PADDING(name) struct zone_padding name; #else #define ZONE_PADDING(name) @@ -233,7 +233,7 @@ struct zone { * rarely used fields: */ char *name; -} ____cacheline_maxaligned_in_smp; +} ____cacheline_internodealigned_in_smp; /* diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index a471f3bb713..51747cd88d1 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -65,7 +65,7 @@ struct rcu_ctrlblk { long cur; /* Current batch number. */ long completed; /* Number of the last completed batch */ int next_pending; /* Is the next batch already waiting? */ -} ____cacheline_maxaligned_in_smp; +} ____cacheline_internodealigned_in_smp; /* Is batch a before batch b ? */ static inline int rcu_batch_before(long a, long b) diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 48d3bce465b..c9afc61240e 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -61,9 +61,9 @@ struct rcu_state { /* for current batch to proceed. */ }; -static struct rcu_state rcu_state ____cacheline_maxaligned_in_smp = +static struct rcu_state rcu_state ____cacheline_internodealigned_in_smp = {.lock = SPIN_LOCK_UNLOCKED, .cpumask = CPU_MASK_NONE }; -static struct rcu_state rcu_bh_state ____cacheline_maxaligned_in_smp = +static struct rcu_state rcu_bh_state ____cacheline_internodealigned_in_smp = {.lock = SPIN_LOCK_UNLOCKED, .cpumask = CPU_MASK_NONE }; DEFINE_PER_CPU(struct rcu_data, rcu_data) = { 0L }; diff --git a/mm/sparse.c b/mm/sparse.c index 72079b538e2..0a51f36ba3a 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -18,10 +18,10 @@ */ #ifdef CONFIG_SPARSEMEM_EXTREME struct mem_section *mem_section[NR_SECTION_ROOTS] - ____cacheline_maxaligned_in_smp; + ____cacheline_internodealigned_in_smp; #else struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] - ____cacheline_maxaligned_in_smp; + ____cacheline_internodealigned_in_smp; #endif EXPORT_SYMBOL(mem_section); |