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Commit dd4cb9f8 authored by Jack Steiner's avatar Jack Steiner Committed by Tony Luck
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[IA64-SGI] - Reduce overhead of reading sn_topology 



MPI programs using certain debug options have a long
startup time. This was traced to a "vmalloc/vfree" in
the code that reads /proc/sgi_sn/sn_topology. On large
systems, vfree requires an IPI to all cpus to do TLB
purging.

Replace the vmalloc/vfree with kmalloc/kfree. Although
the size of the structure being allocated is unknown, it
will not not exceed 96 bytes.

Signed-off-by: default avatarJack Steiner <steiner@sgi.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent f0fe253c

arch/ia64/sn/kernel/sn2/sn_hwperf.c

+2 −2
Original line number Diff line number Diff line
@@ -493,7 +493,7 @@ static int sn_topology_show(struct seq_file *s, void *d) 
		 * numalink ports

		 */

		sz = obj->ports * sizeof(struct sn_hwperf_port_info);

		if ((ptdata = vmalloc(sz)) == NULL)

		if ((ptdata = kmalloc(sz, GFP_KERNEL)) == NULL)

			return -ENOMEM;

		e = ia64_sn_hwperf_op(sn_hwperf_master_nasid,

				      SN_HWPERF_ENUM_PORTS, obj->id, sz,
@@ -541,7 +541,7 @@ static int sn_topology_show(struct seq_file *s, void *d) 
				(SN_HWPERF_IS_NL3ROUTER(obj) ||

				SN_HWPERF_IS_NL3ROUTER(p)) ?  "LLP3" : "LLP4");

		}

		vfree(ptdata);

		kfree(ptdata);

	}



	return 0;