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: Jack Steiner <steiner@xxxxxxx> Index: linux/arch/ia64/sn/kernel/sn2/sn_hwperf.c =================================================================== --- linux.orig/arch/ia64/sn/kernel/sn2/sn_hwperf.c 2006-04-22 09:24:01.969360448 -0500 +++ linux/arch/ia64/sn/kernel/sn2/sn_hwperf.c 2006-04-22 09:24:24.403090461 -0500 @@ -493,7 +493,7 @@ static int sn_topology_show(struct seq_f * 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_f (SN_HWPERF_IS_NL3ROUTER(obj) || SN_HWPERF_IS_NL3ROUTER(p)) ? "LLP3" : "LLP4"); } - vfree(ptdata); + kfree(ptdata); } return 0; - : send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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