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| author | Rik van Riel <riel@redhat.com> | 2015-04-24 15:24:28 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-05-20 00:15:09 -0700 |
| commit | 6570a9a1ce3a1dd227a065fd8ad16778d827b753 (patch) | |
| tree | c3bcd277013cdc2af71a136d0409023ca4b88118 | |
| parent | 59f30abe94bff50636c8cad45207a01fdcb2ee49 (diff) | |
| download | linux-stable-6570a9a1ce3a1dd227a065fd8ad16778d827b753.tar.gz linux-stable-6570a9a1ce3a1dd227a065fd8ad16778d827b753.tar.bz2 linux-stable-6570a9a1ce3a1dd227a065fd8ad16778d827b753.zip | |
show nohz_full cpus in sysfs
Currently there is no way to query which CPUs are in nohz_full
mode from userspace.
Export the CPU list running in nohz_full mode in sysfs,
specifically in the file /sys/devices/system/cpu/nohz_full
This can be used by system management tools like libvirt,
openstack, and others to ensure proper task placement.
Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Acked-by: Chris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/base/cpu.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index ea23ee7b545b..78720e706176 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -16,6 +16,7 @@ #include <linux/acpi.h> #include <linux/of.h> #include <linux/cpufeature.h> +#include <linux/tick.h> #include "base.h" @@ -276,6 +277,19 @@ static ssize_t print_cpus_isolated(struct device *dev, } static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL); +#ifdef CONFIG_NO_HZ_FULL +static ssize_t print_cpus_nohz_full(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int n = 0, len = PAGE_SIZE-2; + + n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask)); + + return n; +} +static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL); +#endif + static void cpu_device_release(struct device *dev) { /* @@ -443,6 +457,9 @@ static struct attribute *cpu_root_attrs[] = { &dev_attr_kernel_max.attr, &dev_attr_offline.attr, &dev_attr_isolated.attr, +#ifdef CONFIG_NO_HZ_FULL + &dev_attr_nohz_full.attr, +#endif #ifdef CONFIG_GENERIC_CPU_AUTOPROBE &dev_attr_modalias.attr, #endif |