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author | Chris Metcalf <cmetcalf@tilera.com> | 2013-08-12 14:39:22 -0400 |
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committer | Chris Metcalf <cmetcalf@tilera.com> | 2013-09-03 14:51:36 -0400 |
commit | 80f184108e364ba1d08dd77339966034c9a9243e (patch) | |
tree | 5ec0337b5f0184e886d12392704289deeb6acd5b /arch/tile/kernel/sysfs.c | |
parent | 8157107b13099d6eb2e8ccd00b9aba009c698c38 (diff) | |
download | op-kernel-dev-80f184108e364ba1d08dd77339966034c9a9243e.zip op-kernel-dev-80f184108e364ba1d08dd77339966034c9a9243e.tar.gz |
tile: support reporting Tilera hypervisor statistics
Newer hypervisors have an API for reporting per-cpu statistics
information. This change allows seeing that information via
/sys/devices/system/cpu/cpuN/hv_stats file for each core.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Diffstat (limited to 'arch/tile/kernel/sysfs.c')
-rw-r--r-- | arch/tile/kernel/sysfs.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/tile/kernel/sysfs.c b/arch/tile/kernel/sysfs.c index e25b0a8..a3ed12f 100644 --- a/arch/tile/kernel/sysfs.c +++ b/arch/tile/kernel/sysfs.c @@ -157,6 +157,67 @@ hvconfig_bin_read(struct file *filp, struct kobject *kobj, return count; } +static ssize_t hv_stats_show(struct device *dev, + struct device_attribute *attr, + char *page) +{ + int cpu = dev->id; + long lotar = HV_XY_TO_LOTAR(cpu_x(cpu), cpu_y(cpu)); + + ssize_t n = hv_confstr(HV_CONFSTR_HV_STATS, + (unsigned long)page, PAGE_SIZE - 1, + lotar, 0); + n = n < 0 ? 0 : min(n, (ssize_t)PAGE_SIZE - 1); + page[n] = '\0'; + return n; +} + +static ssize_t hv_stats_store(struct device *dev, + struct device_attribute *attr, + const char *page, + size_t count) +{ + int cpu = dev->id; + long lotar = HV_XY_TO_LOTAR(cpu_x(cpu), cpu_y(cpu)); + + ssize_t n = hv_confstr(HV_CONFSTR_HV_STATS, 0, 0, lotar, 1); + return n < 0 ? n : count; +} + +static DEVICE_ATTR(hv_stats, 0644, hv_stats_show, hv_stats_store); + +static int hv_stats_device_add(struct device *dev, struct subsys_interface *sif) +{ + int err, cpu = dev->id; + + if (!cpu_online(cpu)) + return 0; + + err = sysfs_create_file(&dev->kobj, &dev_attr_hv_stats.attr); + + return err; +} + +static int hv_stats_device_remove(struct device *dev, + struct subsys_interface *sif) +{ + int cpu = dev->id; + + if (!cpu_online(cpu)) + return 0; + + sysfs_remove_file(&dev->kobj, &dev_attr_hv_stats.attr); + return 0; +} + + +static struct subsys_interface hv_stats_interface = { + .name = "hv_stats", + .subsys = &cpu_subsys, + .add_dev = hv_stats_device_add, + .remove_dev = hv_stats_device_remove, +}; + static int __init create_sysfs_entries(void) { int err = 0; @@ -188,6 +249,21 @@ static int __init create_sysfs_entries(void) err = sysfs_create_bin_file(hypervisor_kobj, &hvconfig_bin); } + if (!err) { + /* + * Don't bother adding the hv_stats files on each CPU if + * our hypervisor doesn't supply statistics. + */ + int cpu = raw_smp_processor_id(); + long lotar = HV_XY_TO_LOTAR(cpu_x(cpu), cpu_y(cpu)); + char dummy; + ssize_t n = hv_confstr(HV_CONFSTR_HV_STATS, + (unsigned long) &dummy, 1, + lotar, 0); + if (n >= 0) + err = subsys_interface_register(&hv_stats_interface); + } + return err; } subsys_initcall(create_sysfs_entries); |