Add cacheline alignment to some critical SMP management maps. These are in particular important for NUMA systems to avoid false sharing.
Signed-off-by: Christoph Lameter <[EMAIL PROTECTED]> Signed-off-by: Shai Fultheim <[EMAIL PROTECTED]> Index: linux-2.6.11/arch/i386/kernel/smpboot.c =================================================================== --- linux-2.6.11.orig/arch/i386/kernel/smpboot.c 2005-03-14 10:32:53.349590752 -0800 +++ linux-2.6.11/arch/i386/kernel/smpboot.c 2005-03-14 10:33:48.592192600 -0800 @@ -64,7 +64,7 @@ int phys_proc_id[NR_CPUS]; /* Package ID EXPORT_SYMBOL(phys_proc_id); /* bitmap of online cpus */ -cpumask_t cpu_online_map; +cpumask_t cpu_online_map __cacheline_aligned; cpumask_t cpu_callin_map; cpumask_t cpu_callout_map; @@ -472,10 +472,10 @@ extern struct { #ifdef CONFIG_NUMA /* which logical CPUs are on which nodes */ -cpumask_t node_2_cpu_mask[MAX_NUMNODES] = +cpumask_t node_2_cpu_mask[MAX_NUMNODES] __cacheline_aligned = { [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE }; /* which node each logical CPU is on */ -int cpu_2_node[NR_CPUS] = { [0 ... NR_CPUS-1] = 0 }; +int cpu_2_node[NR_CPUS] __cacheline_aligned = { [0 ... NR_CPUS-1] = 0 }; EXPORT_SYMBOL(cpu_2_node); /* set up a mapping between cpu and node. */ @@ -503,7 +503,8 @@ static inline void unmap_cpu_to_node(int #endif /* CONFIG_NUMA */ -u8 cpu_2_logical_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID }; +u8 cpu_2_logical_apicid[NR_CPUS] __cacheline_aligned = + { [0 ... NR_CPUS-1] = BAD_APICID }; static void map_cpu_to_logical_apicid(void) { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/