lkml.org 
[lkml]   [2013]   [Aug]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH] 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>
---
arch/tile/include/hv/hypervisor.h | 16 +++++++--
arch/tile/kernel/sysfs.c | 76 +++++++++++++++++++++++++++++++++++++++
2 files changed, 89 insertions(+), 3 deletions(-)

diff --git a/arch/tile/include/hv/hypervisor.h b/arch/tile/include/hv/hypervisor.h
index 71abe38..e944974 100644
--- a/arch/tile/include/hv/hypervisor.h
+++ b/arch/tile/include/hv/hypervisor.h
@@ -559,14 +559,24 @@ typedef enum {
HV_CONFSTR_CPUMOD_REV = 18,

/** Human-readable CPU module description. */
- HV_CONFSTR_CPUMOD_DESC = 19
+ HV_CONFSTR_CPUMOD_DESC = 19,
+
+ /** Per-tile hypervisor statistics. When this identifier is specified,
+ * the hv_confstr call takes two extra arguments. The first is the
+ * HV_XY_TO_LOTAR of the target tile's coordinates. The second is
+ * a flag word. The only current flag is the lowest bit, which means
+ * "zero out the stats instead of retrieving them"; in this case the
+ * buffer and buffer length are ignored. */
+ HV_CONFSTR_HV_STATS = 20

} HV_ConfstrQuery;

/** Query a configuration string from the hypervisor.
*
* @param query Identifier for the specific string to be retrieved
- * (HV_CONFSTR_xxx).
+ * (HV_CONFSTR_xxx). Some strings may require or permit extra
+ * arguments to be appended which select specific objects to be
+ * described; see the string descriptions above.
* @param buf Buffer in which to place the string.
* @param len Length of the buffer.
* @return If query is valid, then the length of the corresponding string,
@@ -574,7 +584,7 @@ typedef enum {
* was truncated. If query is invalid, HV_EINVAL. If the specified
* buffer is not writable by the client, HV_EFAULT.
*/
-int hv_confstr(HV_ConfstrQuery query, HV_VirtAddr buf, int len);
+int hv_confstr(HV_ConfstrQuery query, HV_VirtAddr buf, int len, ...);

/** Tile coordinate */
typedef struct
diff --git a/arch/tile/kernel/sysfs.c b/arch/tile/kernel/sysfs.c
index 024b978..575bda8 100644
--- a/arch/tile/kernel/sysfs.c
+++ b/arch/tile/kernel/sysfs.c
@@ -161,6 +161,67 @@ 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;
@@ -192,6 +253,21 @@ 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);
--
1.8.3.1


\
 
 \ /
  Last update: 2013-08-12 22:01    [W:0.021 / U:0.536 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site