On Mon, Mar 24, 2014 at 03:32:54PM -0400, Don Zickus wrote:
> This patch figures out the max number of cpus and nodes that are on the
> system and creates a map of cpu to node. This allows us to provide a cpu
> and quickly get the node associated with it.
>
> It was mostly copied from builtin-kmem.c and tweaked slightly to use less
> memory
> (use possible cpus instead of max). It also calculates the max number of
> nodes.
>
> V3: simplify function names
some nits below, but I think Arnaldo should
see/check the namespace ;-)
thanks,
jirka
>
> Signed-off-by: Don Zickus <dzic...@redhat.com>
> ---
> tools/perf/util/cpumap.c | 139
> +++++++++++++++++++++++++++++++++++++++++++++++
> tools/perf/util/cpumap.h | 35 ++++++++++++
> 2 files changed, 174 insertions(+)
>
> diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> index 7fe4994..2eb528e 100644
> --- a/tools/perf/util/cpumap.c
> +++ b/tools/perf/util/cpumap.c
> @@ -317,3 +317,142 @@ int cpu_map__build_core_map(struct cpu_map *cpus,
> struct cpu_map **corep)
> {
> return cpu_map__build_map(cpus, corep, cpu_map__get_core);
> }
> +
> +/* setup simple routines to easily access node numbers given a cpu number */
> +static int __set_max_num(FILE *fp, int *max)
> +{
> + int num;
> + char buf[256];
> +
> + num = fread(&buf, 1, sizeof(buf), fp);
> + if (!num)
> + return -1;
> +
> + buf[num] = '\0';
> +
> + /* start on the right, to find highest node num */
> + while (--num) {
> + if ((buf[num] == ',') || (buf[num] == '-')) {
> + num++;
> + break;
> + }
> + }
> + if (sscanf(&buf[num], "%d", max) < 1)
> + return -1;
> +
> + /* convert from 0-based to 1-based */
> + (*max)++;
> +
> + return 0;
> +}
> +
> +/* Determine highest possible cpu in the system for sparse allocation */
> +static void set_max_cpu_num(void)
> +{
> + FILE *fp;
> + int ret = -1;
> +
> + /* set up default */
> + max_cpu_num = 4096;
> +
> + /* get the highest possible cpu number for a sparse allocation */
> + fp = fopen("/sys/devices/system/cpu/possible", "r");
> + if (!fp)
> + goto out;
> +
> + ret = __set_max_num(fp, &max_cpu_num);
> +
> + fclose(fp);
> +
> +out:
> + if (ret)
> + pr_err("Failed to read max cpus, using default of %d\n",
> + max_cpu_num);
> + return;
> +}
> +
> +/* Determine highest possible node in the system for sparse allocation */
> +static void set_max_node_num(void)
> +{
> + FILE *fp;
> + int ret = -1;
> +
> + /* set up default */
> + max_node_num = 8;
> +
> + /* get the highest possible cpu number for a sparse allocation */
> + fp = fopen("/sys/devices/system/node/possible", "r");
> + if (!fp)
> + goto out;
any reason why not put fopen/fclose into __set_max_num ?
also looks like 'get_max_num' would fit better for __set_max_num ;-)
> +
> + ret = __set_max_num(fp, &max_node_num);
> +
> + fclose(fp);
> +
^^^ whitespace
> +out:
> + if (ret)
> + pr_err("Failed to read max nodes, using default of %d\n",
> + max_node_num);
> + return;
> +}
> +
> +static int init_cpunode_map(void)
> +{
> + int i;
> +
> + set_max_cpu_num();
> + set_max_node_num();
> +
> + cpunode_map = calloc(max_cpu_num, sizeof(int));
> + if (!cpunode_map) {
> + pr_err("%s: calloc failed\n", __func__);
> + goto out;
> + }
> +
> + for (i = 0; i < max_cpu_num; i++)
> + cpunode_map[i] = -1;
> +
> + return 0;
> +out:
> + return -1;
> +}
> +
> +#define PATH_SYS_NODE "/sys/devices/system/node"
> +
> +int cpu__setup_cpunode_map(void)
> +{
> + struct dirent *dent1, *dent2;
> + DIR *dir1, *dir2;
> + unsigned int cpu, mem;
> + char buf[PATH_MAX];
> +
> + /* initialize globals */
> + if (init_cpunode_map())
> + return -1;
> +
> + dir1 = opendir(PATH_SYS_NODE);
> + if (!dir1)
> + return 0;
> +
> + /* walk tree and setup map */
> + while ((dent1 = readdir(dir1)) != NULL) {
> + if (dent1->d_type != DT_DIR ||
> + sscanf(dent1->d_name, "node%u", &mem) < 1)
> + continue;
> +
> + snprintf(buf, PATH_MAX, "%s/%s", PATH_SYS_NODE, dent1->d_name);
> + dir2 = opendir(buf);
> + if (!dir2)
> + continue;
> + while ((dent2 = readdir(dir2)) != NULL) {
> + if (dent2->d_type != DT_LNK ||
> + sscanf(dent2->d_name, "cpu%u", &cpu) < 1)
> + continue;
> + cpunode_map[cpu] = mem;
> + }
> + closedir(dir2);
> + }
> + closedir(dir1);
> + return 0;
> +}
> +
^^^ white space
> diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
> index b123bb9..ce3c5a0 100644
> --- a/tools/perf/util/cpumap.h
> +++ b/tools/perf/util/cpumap.h
> @@ -4,6 +4,9 @@
> #include <stdio.h>
> #include <stdbool.h>
>
> +#include "perf.h"
> +#include "util/debug.h"
> +
> struct cpu_map {
> int nr;
> int map[];
> @@ -46,4 +49,36 @@ static inline bool cpu_map__empty(const struct cpu_map
> *map)
> return map ? map->map[0] == -1 : true;
> }
>
> +int max_cpu_num;
> +int max_node_num;
> +int *cpunode_map;
> +
> +int cpu__setup_cpunode_map(void);
> +
> +static inline int cpu__max_node(void)
> +{
> + if (unlikely(!max_node_num))
> + pr_debug("cpu_map not initiailzed\n");
typo: initialized
> +
> + return max_node_num;
> +}
> +
> +static inline int cpu__max_cpu(void)
> +{
> + if (unlikely(!max_cpu_num))
> + pr_debug("cpu_map not initiailzed\n");
ditto
> +
> + return max_cpu_num;
> +}
> +
> +static inline int cpu__get_node(int cpu)
> +{
> + if (unlikely(cpunode_map == NULL)) {
> + pr_debug("cpu_map not initialized\n");
ditto
> + return -1;
> + }
> +
> + return cpunode_map[cpu];
> +}
> +
> #endif /* __PERF_CPUMAP_H */
> --
> 1.7.11.7
>
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