add read_slabinfo

Summary: Add function to read /proc/slabinfo

Reviewed By: brianc118

Differential Revision: D53074161

fbshipit-source-id: c8831237b4709a79d40abebf2f69faee5cdbe017

3 files changed, 157 insertions, 0 deletions

diff --git a/below/procfs/src/lib.rs b/below/procfs/src/lib.rs
index c3f0afaa..bc614ab4 100644
--- a/below/procfs/src/lib.rs
+++ b/below/procfs/src/lib.rs
@@ -393,6 +393,35 @@ impl ProcReader {
         }
     }
 
+    pub fn read_slabinfo(&self) -> Result<SlabInfoMap> {
+        let path = self.path.join("slabinfo");
+        let file = File::open(&path).map_err(|e| Error::IoError(path.clone(), e))?;
+        let buf_reader = BufReader::new(file);
+        let mut slab_info_map: SlabInfoMap = Default::default();
+
+        // The first line is version, second line is headers:
+        //
+        // slabinfo - version: 2.1
+        // # name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> : tunables <limit> <batchcount> <sharedfactor> : slabdata <active_slabs> <num_slabs> <sharedavail>
+        //
+        for line in buf_reader.lines().skip(2) {
+            let line = line.map_err(|e| Error::IoError(path.clone(), e))?;
+            let mut items = line.split_whitespace();
+            let mut slab_info: SlabInfo = Default::default();
+            let name = items.next().unwrap().to_owned();
+            slab_info.name = Some(name.clone());
+            slab_info.active_objs = parse_item!(path, items.next(), u64, line)?;
+            slab_info.num_objs = parse_item!(path, items.next(), u64, line)?;
+            slab_info.obj_size = parse_item!(path, items.next(), u64, line)?;
+            slab_info.obj_per_slab = parse_item!(path, items.next(), u64, line)?;
+            slab_info.pages_per_slab = parse_item!(path, items.next(), u64, line)?;
+            slab_info.active_slabs = parse_item!(path, items.nth(7), u64, line)?;
+            slab_info.num_slabs = parse_item!(path, items.next(), u64, line)?;
+            slab_info_map.insert(name, slab_info);
+        }
+        Ok(slab_info_map)
+    }
+
     fn read_disk_fsinfo(&self, mount_info: &MountInfo) -> Option<(f32, u64)> {
         if let Some(mount_point) = &mount_info.mount_point {
             if let Ok(stat) = sys::statvfs::statvfs(Path::new(&mount_point)) {
diff --git a/below/procfs/src/test.rs b/below/procfs/src/test.rs
index eac2e2c7..301084db 100644
--- a/below/procfs/src/test.rs
+++ b/below/procfs/src/test.rs
@@ -464,6 +464,121 @@ swap_ra_hit 139012
 }
 
 #[test]
+fn test_read_slabinfo() {
+    let slabinfo = b"slabinfo - version: 2.1
+    # name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> : tunables <limit> <batchcount> <sharedfactor> : slabdata <active_slabs> <num_slabs> <sharedavail>
+    zs_handle         3860100 6265344      8  512    1 : tunables    0    0    0 : slabdata  12237  12237      0
+    kvm_async_pf           0      0    136   30    1 : tunables    0    0    0 : slabdata      0      0      0
+    kvm_vcpu               0      0   9792    3    8 : tunables    0    0    0 : slabdata      0      0      0
+    kvm_mmu_page_header      0      0    184   44    2 : tunables    0    0    0 : slabdata      0      0      0
+    x86_emulator           0      0   2672   12    8 : tunables    0    0    0 : slabdata      0      0      0
+    x86_fpu                0      0   4160    7    8 : tunables    0    0    0 : slabdata      0      0      0
+    ext4_groupinfo_1k     90     90    136   30    1 : tunables    0    0    0 : slabdata      3      3      0
+";
+    let procfs = TestProcfs::new();
+    procfs.create_file_with_content("slabinfo", slabinfo);
+    let reader = procfs.get_reader();
+    let slabinfo = reader
+        .read_slabinfo()
+        .expect("Failed to read slabinfo file");
+    let expected_slabinfo = std::collections::BTreeMap::from([
+        (
+            "zs_handle".to_string(),
+            SlabInfo {
+                name: Some("zs_handle".to_string()),
+                active_objs: Some(3860100),
+                num_objs: Some(6265344),
+                obj_size: Some(8),
+                obj_per_slab: Some(512),
+                pages_per_slab: Some(1),
+                active_slabs: Some(12237),
+                num_slabs: Some(12237),
+            },
+        ),
+        (
+            "kvm_async_pf".to_string(),
+            SlabInfo {
+                name: Some("kvm_async_pf".to_string()),
+                active_objs: Some(0),
+                num_objs: Some(0),
+                obj_size: Some(136),
+                obj_per_slab: Some(30),
+                pages_per_slab: Some(1),
+                active_slabs: Some(0),
+                num_slabs: Some(0),
+            },
+        ),
+        (
+            "kvm_vcpu".to_string(),
+            SlabInfo {
+                name: Some("kvm_vcpu".to_string()),
+                active_objs: Some(0),
+                num_objs: Some(0),
+                obj_size: Some(9792),
+                obj_per_slab: Some(3),
+                pages_per_slab: Some(8),
+                active_slabs: Some(0),
+                num_slabs: Some(0),
+            },
+        ),
+        (
+            "kvm_mmu_page_header".to_string(),
+            SlabInfo {
+                name: Some("kvm_mmu_page_header".to_string()),
+                active_objs: Some(0),
+                num_objs: Some(0),
+                obj_size: Some(184),
+                obj_per_slab: Some(44),
+
+                pages_per_slab: Some(2),
+                active_slabs: Some(0),
+                num_slabs: Some(0),
+            },
+        ),
+        (
+            "x86_emulator".to_string(),
+            SlabInfo {
+                name: Some("x86_emulator".to_string()),
+                active_objs: Some(0),
+                num_objs: Some(0),
+                obj_size: Some(2672),
+                obj_per_slab: Some(12),
+                pages_per_slab: Some(8),
+                active_slabs: Some(0),
+                num_slabs: Some(0),
+            },
+        ),
+        (
+            "x86_fpu".to_string(),
+            SlabInfo {
+                name: Some("x86_fpu".to_string()),
+                active_objs: Some(0),
+                num_objs: Some(0),
+                obj_size: Some(4160),
+                obj_per_slab: Some(7),
+                pages_per_slab: Some(8),
+                active_slabs: Some(0),
+                num_slabs: Some(0),
+            },
+        ),
+        (
+            "ext4_groupinfo_1k".to_string(),
+            SlabInfo {
+                name: Some("ext4_groupinfo_1k".to_string()),
+                active_objs: Some(90),
+                num_objs: Some(90),
+                obj_size: Some(136),
+                obj_per_slab: Some(30),
+                pages_per_slab: Some(1),
+                active_slabs: Some(3),
+                num_slabs: Some(3),
+            },
+        ),
+    ]);
+    assert_eq!(slabinfo, expected_slabinfo);
+}
+
+#[test]
 fn test_disk_stat() {
     let diskstats = b"   1       0 ram0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
     1       1 ram1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
diff --git a/below/procfs/src/types.rs b/below/procfs/src/types.rs
index 967769a4..ea326b96 100644
--- a/below/procfs/src/types.rs
+++ b/below/procfs/src/types.rs
@@ -273,6 +273,18 @@ pub struct VmStat {
 }
 
 #[derive(Default, Clone, PartialEq, Debug, Serialize, Deserialize)]
+pub struct SlabInfo {
+    pub name: Option<String>,
+    pub active_objs: Option<u64>,
+    pub num_objs: Option<u64>,
+    pub obj_size: Option<u64>,
+    pub obj_per_slab: Option<u64>,
+    pub pages_per_slab: Option<u64>,
+    pub active_slabs: Option<u64>,
+    pub num_slabs: Option<u64>,
+}
+
+#[derive(Default, Clone, PartialEq, Debug, Serialize, Deserialize)]
 pub struct MountInfo {
     pub mnt_id: Option<i32>,
     pub parent_mnt_id: Option<i32>,
@@ -374,6 +386,7 @@ pub struct PidInfo {
 pub type PidMap = BTreeMap<i32, PidInfo>;
 pub type NetMap = BTreeMap<String, InterfaceStat>;
 pub type DiskMap = BTreeMap<String, DiskStat>;
+pub type SlabInfoMap = BTreeMap<String, SlabInfo>;
 
 #[derive(Default, Clone, PartialEq, Debug, Serialize, Deserialize)]
 pub struct NetStat {