Balbir Singh wrote:
> Changelog
>
> 1. Get rid of the constant 5 (based on comments from
> [EMAIL PROTECTED])
> 2. Implement suggestions from Olof Johannson
> 3. Check if cmdline is NULL in fake_numa_create_new_node()
>
> Tested with additional parameters from Olof
>
> numa=debug,fake=
> numa=foo,fake=bar
>
>
> Here's a dumb simple implementation of fake NUMA nodes for PowerPC. Fake
> NUMA nodes can be specified using the following command line option
>
> numa=fake=<node range>
>
> node range is of the format <range1>,<range2>,...<rangeN>
>
> Each of the rangeX parameters is passed using memparse(). I find the patch
> useful for fake NUMA emulation on my simple PowerPC machine. I've tested it
> on a non-numa box with the following arguments
>
> numa=fake=1G
> numa=fake=1G,2G
> name=fake=1G,512M,2G
> numa=fake=1500M,2800M mem=3500M
> numa=fake=1G mem=512M
> numa=fake=1G mem=1G
>
> This patch applies on top of 2.6.24-rc4.
>
> All though I've tried my best to handle some of the architecture specific
> details of PowerPC, I might have overlooked something obvious, like the usage
> of an API or some architecture tweaks. The patch depends on CONFIG_NUMA and
> I decided against creating a separate config option for fake NUMA to keep
> the code simple.
>
> Comments are as always welcome!
>
> Signed-off-by: Balbir Singh <[EMAIL PROTECTED]>
> ---
>
> arch/powerpc/mm/numa.c | 59
> ++++++++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 54 insertions(+), 5 deletions(-)
>
> diff -puN arch/powerpc/mm/numa.c~ppc-fake-numa-easy arch/powerpc/mm/numa.c
> --- linux-2.6.24-rc4-mm1/arch/powerpc/mm/numa.c~ppc-fake-numa-easy
> 2007-12-07 21:25:55.000000000 +0530
> +++ linux-2.6.24-rc4-mm1-balbir/arch/powerpc/mm/numa.c 2007-12-08
> 03:19:46.000000000 +0530
> @@ -24,6 +24,8 @@
>
> static int numa_enabled = 1;
>
> +static char *cmdline __initdata;
> +
> static int numa_debug;
> #define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
>
> @@ -39,6 +41,43 @@ static bootmem_data_t __initdata plat_no
> static int min_common_depth;
> static int n_mem_addr_cells, n_mem_size_cells;
>
> +static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn,
> + unsigned int *nid)
> +{
> + unsigned long long mem;
> + char *p = cmdline;
> + static unsigned int fake_nid = 0;
> + static unsigned long long curr_boundary = 0;
> +
> + *nid = fake_nid;
> + if (!p)
> + return 0;
> +
> + mem = memparse(p, &p);
> + if (!mem)
> + return 0;
> +
> + if (mem < curr_boundary)
> + return 0;
> +
> + curr_boundary = mem;
> +
> + if ((end_pfn << PAGE_SHIFT) > mem) {
> + /*
> + * Skip commas and spaces
> + */
> + while (*p == ',' || *p == ' ' || *p == '\t')
> + p++;
> +
> + cmdline = p;
> + fake_nid++;
> + *nid = fake_nid;
> + dbg("created new fake_node with id %d\n", fake_nid);
> + return 1;
> + }
> + return 0;
> +}
> +
> static void __cpuinit map_cpu_to_node(int cpu, int node)
> {
> numa_cpu_lookup_table[cpu] = node;
> @@ -344,12 +383,14 @@ static void __init parse_drconf_memory(s
> if (nid == 0xffff || nid >= MAX_NUMNODES)
> nid = default_nid;
> }
> - node_set_online(nid);
>
> size = numa_enforce_memory_limit(start, lmb_size);
> if (!size)
> continue;
>
> + fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
> + node_set_online(nid);
> +
> add_active_range(nid, start >> PAGE_SHIFT,
> (start >> PAGE_SHIFT) + (size >> PAGE_SHIFT));
> }
> @@ -429,7 +470,6 @@ new_range:
> nid = of_node_to_nid_single(memory);
> if (nid < 0)
> nid = default_nid;
> - node_set_online(nid);
>
> if (!(size = numa_enforce_memory_limit(start, size))) {
> if (--ranges)
> @@ -438,6 +478,9 @@ new_range:
> continue;
> }
>
> + fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
> + node_set_online(nid);
> +
> add_active_range(nid, start >> PAGE_SHIFT,
> (start >> PAGE_SHIFT) + (size >> PAGE_SHIFT));
>
> @@ -461,7 +504,7 @@ static void __init setup_nonnuma(void)
> unsigned long top_of_ram = lmb_end_of_DRAM();
> unsigned long total_ram = lmb_phys_mem_size();
> unsigned long start_pfn, end_pfn;
> - unsigned int i;
> + unsigned int i, nid = 0;
>
> printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
> top_of_ram, total_ram);
> @@ -471,9 +514,11 @@ static void __init setup_nonnuma(void)
> for (i = 0; i < lmb.memory.cnt; ++i) {
> start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
> end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
> - add_active_range(0, start_pfn, end_pfn);
> +
> + fake_numa_create_new_node(end_pfn, &nid);
> + add_active_range(nid, start_pfn, end_pfn);
> + node_set_online(nid);
> }
> - node_set_online(0);
> }
>
> void __init dump_numa_cpu_topology(void)
> @@ -702,6 +747,10 @@ static int __init early_numa(char *p)
> if (strstr(p, "debug"))
> numa_debug = 1;
>
> + p = strstr(p, "fake=");
> + if (p)
> + cmdline = p + strlen("fake=");
> +
> return 0;
> }
> early_param("numa", early_numa);
> _
>
If there are no other major objections, could we get this infrastructure
into -mm?
--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
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