Messages in this thread Patch in this message | | | Date | Tue, 15 Mar 2005 20:12:55 -0800 (PST) | From | Christoph Lameter <> | Subject | [PATCH] cacheline alignment for cpu maps |
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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 <christoph@lameter.com> Signed-off-by: Shai Fultheim <Shai@Scalex86.org>
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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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