cgroupfs: Add Pids controller (#8215)

Summary: Pull Request resolved: https://github.com/facebookincubator/below/pull/8215

Reviewed By: antonis-m

Differential Revision: D52055696

Pulled By: brianc118

fbshipit-source-id: 4c6afc22c89ab21d18b018c5b8294f1f2420375e

9 files changed, 83 insertions, 2 deletions

diff --git a/below/cgroupfs/src/lib.rs b/below/cgroupfs/src/lib.rs
index 8ca6d27e..2688bdc7 100644
--- a/below/cgroupfs/src/lib.rs
+++ b/below/cgroupfs/src/lib.rs
@@ -344,6 +344,16 @@ impl CgroupReader {
         self.read_singleline_controllers("cgroup.subtree_control")
     }
 
+    /// Read pids.current - returning current cgroup number of processes
+    pub fn read_pids_current(&self) -> Result<u64> {
+        self.read_singleline_file("pids.current")
+    }
+
+    /// Read pids.max - returning max cgroup number of processes
+    pub fn read_pids_max(&self) -> Result<i64> {
+        self.read_singleline_integer_or_max_stat_file("pids.max")
+    }
+
     /// Read memory.min - returning memory.min limit in bytes
     /// Will return -1 if the content is max
     pub fn read_memory_min(&self) -> Result<i64> {
diff --git a/below/cgroupfs/src/test.rs b/below/cgroupfs/src/test.rs
index 50111dda..2fea2316 100644
--- a/below/cgroupfs/src/test.rs
+++ b/below/cgroupfs/src/test.rs
@@ -139,6 +139,7 @@ macro_rules! singleline_integer_or_max_test {
     };
 }
 
+singleline_integer_or_max_test!(read_pids_max, "pids.max");
 singleline_integer_or_max_test!(read_memory_min, "memory.min");
 singleline_integer_or_max_test!(read_memory_low, "memory.low");
 singleline_integer_or_max_test!(read_memory_high, "memory.high");
@@ -146,6 +147,7 @@ singleline_integer_or_max_test!(read_memory_max, "memory.max");
 singleline_integer_or_max_test!(read_memory_swap_max, "memory.swap.max");
 singleline_integer_or_max_test!(read_memory_zswap_max, "memory.zswap.max");
 
+test_success!(read_pids_current, "pids.current", b"10000\n", 10000);
 test_success!(read_cpu_weight, "cpu.weight", b"10000\n", 10000);
 test_failure!(read_cpu_weight, "cpu.weight", b"5000000000\n");
 test_success!(
diff --git a/below/dump/src/command.rs b/below/dump/src/command.rs
index b633e72c..300a61af 100644
--- a/below/dump/src/command.rs
+++ b/below/dump/src/command.rs
@@ -549,6 +549,7 @@ pub enum CgroupAggField {
     Cpu,
     Mem,
     Io,
+    Pids,
     Pressure,
 }
 
@@ -557,6 +558,7 @@ impl AggField<SingleCgroupModelFieldId> for CgroupAggField {
         use model::CgroupCpuModelFieldId as Cpu;
         use model::CgroupIoModelFieldId as Io;
         use model::CgroupMemoryModelFieldId as Mem;
+        use model::CgroupPidsModelFieldId as Pid;
         use model::CgroupPressureModelFieldId as Pressure;
         use model::SingleCgroupModelFieldId as FieldId;
 
@@ -565,6 +567,7 @@ impl AggField<SingleCgroupModelFieldId> for CgroupAggField {
                 Self::Cpu => enum_iterator::all::<Cpu>().map(FieldId::Cpu).collect(),
                 Self::Mem => enum_iterator::all::<Mem>().map(FieldId::Mem).collect(),
                 Self::Io => enum_iterator::all::<Io>().map(FieldId::Io).collect(),
+                Self::Pids => enum_iterator::all::<Pid>().map(FieldId::Pids).collect(),
                 Self::Pressure => enum_iterator::all::<Pressure>()
                     .map(FieldId::Pressure)
                     .collect(),
@@ -575,6 +578,7 @@ impl AggField<SingleCgroupModelFieldId> for CgroupAggField {
                 Self::Cpu => vec![FieldId::Cpu(Cpu::UsagePct)],
                 Self::Mem => vec![FieldId::Mem(Mem::Total)],
                 Self::Io => vec![FieldId::Io(Io::RbytesPerSec), FieldId::Io(Io::WbytesPerSec)],
+                Self::Pids => vec![FieldId::Pids(Pid::TidsCurrent)],
                 Self::Pressure => vec![
                     FieldId::Pressure(Pressure::CpuSomePct),
                     FieldId::Pressure(Pressure::MemoryFullPct),
diff --git a/below/model/src/cgroup.rs b/below/model/src/cgroup.rs
index 4917f26b..c0e9aeed 100644
--- a/below/model/src/cgroup.rs
+++ b/below/model/src/cgroup.rs
@@ -14,7 +14,7 @@
 
 use super::*;
 
-/// Collection of all data local to the cgroup, e.g. its memory/io/cpu usage.
+/// Collection of all data local to the cgroup, e.g. its memory/io/cpu/pids usage.
 /// Nothing about child cgroups or siblings, and therefore "Single" in its name.
 #[derive(Clone, Debug, Default, Serialize, Deserialize, below_derive::Queriable)]
 pub struct SingleCgroupModel {
@@ -32,6 +32,9 @@ pub struct SingleCgroupModel {
     #[queriable(preferred_name = mem)]
     pub memory: Option<CgroupMemoryModel>,
     #[queriable(subquery)]
+    #[queriable(preferred_name = pids)]
+    pub pids: Option<CgroupPidsModel>,
+    #[queriable(subquery)]
     #[queriable(preferred_name = io_details)]
     pub io: Option<BTreeMap<String, CgroupIoModel>>,
     #[queriable(subquery)]
@@ -220,6 +223,8 @@ impl CgroupModel {
 
         let memory = Some(CgroupMemoryModel::new(sample, last));
 
+        let pids = Some(CgroupPidsModel::new(sample));
+
         let pressure = sample
             .pressure
             .as_ref()
@@ -278,6 +283,7 @@ impl CgroupModel {
                 properties,
                 cpu,
                 memory,
+                pids,
                 io,
                 io_total,
                 pressure,
@@ -720,6 +726,36 @@ impl CgroupMemoryModel {
     Deserialize,
     below_derive::Queriable
 )]
+pub struct CgroupPidsModel {
+    pub tids_current: Option<u64>,
+}
+
+impl std::ops::Add for CgroupPidsModel {
+    type Output = Self;
+
+    fn add(self, other: Self) -> Self::Output {
+        Self {
+            tids_current: opt_add(self.tids_current, other.tids_current),
+        }
+    }
+}
+
+impl CgroupPidsModel {
+    pub fn new(sample: &CgroupSample) -> Self {
+        let tids_current = sample.tids_current;
+        CgroupPidsModel { tids_current }
+    }
+}
+
+#[derive(
+    Clone,
+    Debug,
+    Default,
+    PartialEq,
+    Serialize,
+    Deserialize,
+    below_derive::Queriable
+)]
 pub struct CgroupPressureModel {
     pub cpu_some_pct: Option<f64>,
     pub cpu_full_pct: Option<f64>,
@@ -876,6 +912,7 @@ impl CgroupMemoryNumaModel {
 pub struct CgroupProperties {
     pub cgroup_controllers: Option<BTreeSet<String>>,
     pub cgroup_subtree_control: Option<BTreeSet<String>>,
+    pub tids_max: Option<i64>,
     pub memory_min: Option<i64>,
     pub memory_low: Option<i64>,
     pub memory_high: Option<i64>,
@@ -896,6 +933,7 @@ impl CgroupProperties {
         Self {
             cgroup_controllers: sample.cgroup_controllers.clone(),
             cgroup_subtree_control: sample.cgroup_subtree_control.clone(),
+            tids_max: sample.tids_max,
             memory_min: sample.memory_min,
             memory_low: sample.memory_low,
             memory_high: sample.memory_high,
diff --git a/below/model/src/collector.rs b/below/model/src/collector.rs
index dd7ab9b5..5e08e34d 100644
--- a/below/model/src/collector.rs
+++ b/below/model/src/collector.rs
@@ -376,6 +376,8 @@ fn collect_cgroup_sample(
     Ok(CgroupSample {
         cpu_stat: wrap(reader.read_cpu_stat())?.map(Into::into),
         io_stat,
+        tids_current: wrap(reader.read_pids_current())?,
+        tids_max: wrap(reader.read_pids_max())?,
         memory_current: wrap(reader.read_memory_current().map(|v| v as i64))?,
         memory_stat: wrap(reader.read_memory_stat())?.map(Into::into),
         pressure: pressure_wrap(reader.read_pressure())?.map(Into::into),
diff --git a/below/model/src/common_field_ids.rs b/below/model/src/common_field_ids.rs
index 12b8e9e0..59c2b61f 100644
--- a/below/model/src/common_field_ids.rs
+++ b/below/model/src/common_field_ids.rs
@@ -23,7 +23,7 @@
 ///
 /// This list also servers as documentation for available field ids that could
 /// be used in other below crates. A test ensures that this list is up-to-date.
-pub const COMMON_MODEL_FIELD_IDS: [&str; 408] = [
+pub const COMMON_MODEL_FIELD_IDS: [&str; 410] = [
     "system.hostname",
     "system.kernel_version",
     "system.os_release",
@@ -140,6 +140,7 @@ pub const COMMON_MODEL_FIELD_IDS: [&str; 408] = [
     "cgroup.[path:/<cgroup_path>/.]props.cpuset_cpus_effective",
     "cgroup.[path:/<cgroup_path>/.]props.cpuset_mems",
     "cgroup.[path:/<cgroup_path>/.]props.cpuset_mems_effective",
+    "cgroup.[path:/<cgroup_path>/.]props.tids_max",
     "cgroup.[path:/<cgroup_path>/.]props.memory_high",
     "cgroup.[path:/<cgroup_path>/.]props.memory_low",
     "cgroup.[path:/<cgroup_path>/.]props.memory_max",
@@ -152,6 +153,7 @@ pub const COMMON_MODEL_FIELD_IDS: [&str; 408] = [
     "cgroup.[path:/<cgroup_path>/.]cpu.nr_periods_per_sec",
     "cgroup.[path:/<cgroup_path>/.]cpu.nr_throttled_per_sec",
     "cgroup.[path:/<cgroup_path>/.]cpu.throttled_pct",
+    "cgroup.[path:/<cgroup_path>/.]pids.tids_current",
     "cgroup.[path:/<cgroup_path>/.]mem.total",
     "cgroup.[path:/<cgroup_path>/.]mem.swap",
     "cgroup.[path:/<cgroup_path>/.]mem.anon",
diff --git a/below/model/src/sample.rs b/below/model/src/sample.rs
index 5788f9e2..603a528c 100644
--- a/below/model/src/sample.rs
+++ b/below/model/src/sample.rs
@@ -29,6 +29,8 @@ pub struct Sample {
 pub struct CgroupSample {
     pub cpu_stat: Option<cgroupfs::CpuStat>,
     pub io_stat: Option<BTreeMap<String, cgroupfs::IoStat>>,
+    pub tids_current: Option<u64>,
+    pub tids_max: Option<i64>,
     pub memory_current: Option<i64>,
     pub memory_stat: Option<cgroupfs::MemoryStat>,
     pub pressure: Option<cgroupfs::Pressure>,
diff --git a/below/render/src/default_configs.rs b/below/render/src/default_configs.rs
index be35ca48..1bf9ee9d 100644
--- a/below/render/src/default_configs.rs
+++ b/below/render/src/default_configs.rs
@@ -44,6 +44,7 @@ impl HasRenderConfig for model::SingleCgroupModel {
                 model::CgroupMemoryNumaModel::get_render_config_builder(&field_id.subquery_id)
             }
             Props(field_id) => model::CgroupProperties::get_render_config_builder(field_id),
+            Pids(field_id) => model::CgroupPidsModel::get_render_config_builder(field_id),
         }
     }
 }
@@ -154,6 +155,7 @@ impl HasRenderConfigForDump for model::SingleCgroupModel {
         use model::CgroupCpuModelFieldId::*;
         use model::CgroupIoModelFieldId::*;
         use model::CgroupMemoryModelFieldId::*;
+        use model::CgroupPidsModelFieldId::*;
         use model::CgroupPressureModelFieldId::*;
         use model::CgroupStatModelFieldId::*;
         use model::SingleCgroupModelFieldId::*;
@@ -175,6 +177,9 @@ impl HasRenderConfigForDump for model::SingleCgroupModel {
                 NrThrottledPerSec => Some(gauge),
                 ThrottledPct => Some(gauge.unit("percent")),
             },
+            Pids(field_id) => match field_id {
+                TidsCurrent => Some(counter.unit("count")),
+            },
             Io(field_id) => match field_id {
                 RbytesPerSec => Some(gauge.unit("bytes_per_second")),
                 WbytesPerSec => Some(gauge.unit("bytes_per_second")),
@@ -276,6 +281,16 @@ impl HasRenderConfig for model::CgroupCpuModel {
     }
 }
 
+impl HasRenderConfig for model::CgroupPidsModel {
+    fn get_render_config_builder(field_id: &Self::FieldId) -> RenderConfigBuilder {
+        use model::CgroupPidsModelFieldId::*;
+        let rc = RenderConfigBuilder::new();
+        match field_id {
+            TidsCurrent => rc.title("Tids Current").format(Precision(1)),
+        }
+    }
+}
+
 impl HasRenderConfig for model::CgroupIoModel {
     fn get_render_config_builder(field_id: &Self::FieldId) -> RenderConfigBuilder {
         use model::CgroupIoModelFieldId::*;
@@ -1476,6 +1491,7 @@ impl HasRenderConfig for model::CgroupProperties {
             // "cpu cpuset hugetlb io memory pids" is 33 chars
             CgroupControllers => rc.title("Controllers").width(35),
             CgroupSubtreeControl => rc.title("SubtreeControl").width(35),
+            TidsMax => rc.title("Tids Max").format(MaxOrReadableSize),
             MemoryMin => rc.title("Mem Min").format(MaxOrReadableSize),
             MemoryLow => rc.title("Mem Low").format(MaxOrReadableSize),
             MemoryHigh => rc.title("Mem High").format(MaxOrReadableSize),
diff --git a/below/view/src/cgroup_tabs.rs b/below/view/src/cgroup_tabs.rs
index da2798c5..4c23db5a 100644
--- a/below/view/src/cgroup_tabs.rs
+++ b/below/view/src/cgroup_tabs.rs
@@ -283,6 +283,7 @@ pub mod default_tabs {
     use model::CgroupMemoryModelFieldId::WorkingsetRestoreFile;
     use model::CgroupMemoryModelFieldId::Zswap;
     use model::CgroupMemoryModelFieldId::Zswapped;
+    use model::CgroupPidsModelFieldId::TidsCurrent;
     use model::CgroupPressureModelFieldId::CpuFullPct;
     use model::CgroupPressureModelFieldId::CpuSomePct;
     use model::CgroupPressureModelFieldId::IoFullPct;
@@ -301,6 +302,7 @@ pub mod default_tabs {
     use model::CgroupPropertiesFieldId::MemoryMin;
     use model::CgroupPropertiesFieldId::MemorySwapMax;
     use model::CgroupPropertiesFieldId::MemoryZswapMax;
+    use model::CgroupPropertiesFieldId::TidsMax;
     use model::CgroupStatModelFieldId::NrDescendants;
     use model::CgroupStatModelFieldId::NrDyingDescendants;
     use model::SingleCgroupModelFieldId::CgroupStat;
@@ -308,6 +310,7 @@ pub mod default_tabs {
     use model::SingleCgroupModelFieldId::Io;
     use model::SingleCgroupModelFieldId::Mem;
     use model::SingleCgroupModelFieldId::Name;
+    use model::SingleCgroupModelFieldId::Pids;
     use model::SingleCgroupModelFieldId::Pressure;
     use model::SingleCgroupModelFieldId::Props;
     use once_cell::sync::Lazy;
@@ -333,6 +336,7 @@ pub mod default_tabs {
             ViewItem::from_default(Io(RwbytesPerSec)),
             ViewItem::from_default(CgroupStat(NrDescendants)),
             ViewItem::from_default(CgroupStat(NrDyingDescendants)),
+            ViewItem::from_default(Pids(TidsCurrent)),
         ])
     });
 
@@ -437,6 +441,7 @@ pub mod default_tabs {
             ViewItem::from_default(Props(CpuWeight)),
             ViewItem::from_default(Props(CpusetCpus)),
             ViewItem::from_default(Props(CpusetCpusEffective)),
+            ViewItem::from_default(Props(TidsMax)),
             ViewItem::from_default(Props(CgroupControllers)),
         ])
     });