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authorTejun Heo <tj@kernel.org>2009-10-02 13:28:56 +0900
committerTejun Heo <tj@kernel.org>2009-10-02 13:28:56 +0900
commit52594762a39dfb6338c9d0906ca21dd9ae9453be (patch)
tree4c80dd59ec452c9fe798edf3f4023914c1898a0b /arch/ia64/mm/discontig.c
parent36886478f59ec0fdc24a8877c572b92f8d416aba (diff)
downloadop-kernel-dev-52594762a39dfb6338c9d0906ca21dd9ae9453be.zip
op-kernel-dev-52594762a39dfb6338c9d0906ca21dd9ae9453be.tar.gz
ia64: convert to dynamic percpu allocator
Unlike other archs, ia64 reserves space for percpu areas during early memory initialization. These areas occupy a contiguous region indexed by cpu number on contiguous memory model or are grouped by node on discontiguous memory model. As allocation and initialization are done by the arch code, all that setup_per_cpu_areas() needs to do is communicating the determined layout to the percpu allocator. This patch implements setup_per_cpu_areas() for both contig and discontig memory models and drops HAVE_LEGACY_PER_CPU_AREA. Please note that for contig model, the allocation itself is modified only to allocate for possible cpus instead of NR_CPUS. As dynamic percpu allocator can handle non-direct mapping, there's no reason to allocate memory for cpus which aren't possible. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: linux-ia64 <linux-ia64@vger.kernel.org>
Diffstat (limited to 'arch/ia64/mm/discontig.c')
-rw-r--r--arch/ia64/mm/discontig.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index 200282b..40e4c1f 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -172,6 +172,91 @@ static void *per_cpu_node_setup(void *cpu_data, int node)
return cpu_data;
}
+#ifdef CONFIG_SMP
+/**
+ * setup_per_cpu_areas - setup percpu areas
+ *
+ * Arch code has already allocated and initialized percpu areas. All
+ * this function has to do is to teach the determined layout to the
+ * dynamic percpu allocator, which happens to be more complex than
+ * creating whole new ones using helpers.
+ */
+void __init setup_per_cpu_areas(void)
+{
+ struct pcpu_alloc_info *ai;
+ struct pcpu_group_info *uninitialized_var(gi);
+ unsigned int *cpu_map;
+ void *base;
+ unsigned long base_offset;
+ unsigned int cpu;
+ ssize_t static_size, reserved_size, dyn_size;
+ int node, prev_node, unit, nr_units, rc;
+
+ ai = pcpu_alloc_alloc_info(MAX_NUMNODES, nr_cpu_ids);
+ if (!ai)
+ panic("failed to allocate pcpu_alloc_info");
+ cpu_map = ai->groups[0].cpu_map;
+
+ /* determine base */
+ base = (void *)ULONG_MAX;
+ for_each_possible_cpu(cpu)
+ base = min(base,
+ (void *)(__per_cpu_offset[cpu] + __per_cpu_start));
+ base_offset = (void *)__per_cpu_start - base;
+
+ /* build cpu_map, units are grouped by node */
+ unit = 0;
+ for_each_node(node)
+ for_each_possible_cpu(cpu)
+ if (node == node_cpuid[cpu].nid)
+ cpu_map[unit++] = cpu;
+ nr_units = unit;
+
+ /* set basic parameters */
+ static_size = __per_cpu_end - __per_cpu_start;
+ reserved_size = PERCPU_MODULE_RESERVE;
+ dyn_size = PERCPU_PAGE_SIZE - static_size - reserved_size;
+ if (dyn_size < 0)
+ panic("percpu area overflow static=%zd reserved=%zd\n",
+ static_size, reserved_size);
+
+ ai->static_size = static_size;
+ ai->reserved_size = reserved_size;
+ ai->dyn_size = dyn_size;
+ ai->unit_size = PERCPU_PAGE_SIZE;
+ ai->atom_size = PAGE_SIZE;
+ ai->alloc_size = PERCPU_PAGE_SIZE;
+
+ /*
+ * CPUs are put into groups according to node. Walk cpu_map
+ * and create new groups at node boundaries.
+ */
+ prev_node = -1;
+ ai->nr_groups = 0;
+ for (unit = 0; unit < nr_units; unit++) {
+ cpu = cpu_map[unit];
+ node = node_cpuid[cpu].nid;
+
+ if (node == prev_node) {
+ gi->nr_units++;
+ continue;
+ }
+ prev_node = node;
+
+ gi = &ai->groups[ai->nr_groups++];
+ gi->nr_units = 1;
+ gi->base_offset = __per_cpu_offset[cpu] + base_offset;
+ gi->cpu_map = &cpu_map[unit];
+ }
+
+ rc = pcpu_setup_first_chunk(ai, base);
+ if (rc)
+ panic("failed to setup percpu area (err=%d)", rc);
+
+ pcpu_free_alloc_info(ai);
+}
+#endif
+
/**
* fill_pernode - initialize pernode data.
* @node: the node id.
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