library <stat>: standardized new category calculations

This commit arose out of the discussion (and research)
surrounding the issue cited below. It is an attempt to
consolidate and standardize the calculation of jiffies
categories (e.g. 'idle', 'busy', etc.) once & for all.

Also included is the enum STAT_TIC_NUM_CONTRIBUTORS in
case anyone, in the future, decides to calculate usage
based upon elapsed time * Hz (like top does in process
level %CPU stats). In such an event, a total number of
CPUs or NUMA Nodes would be needed for proper scaling.

Reference(s):
https://gitlab.com/procps-ng/procps/issues/48

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/proc/stat.c b/proc/stat.c
index 9eccb1337b02fe518c9c28938b52f22b34c3dc6e..452860f66efc1b388825b7c5c4dc1c299c64b5c1 100644 (file)
--- a/proc/stat.c
+++ b/proc/stat.c
@@ -57,6 +57,7 @@
 
 struct stat_jifs {
     unsigned long long user, nice, system, idle, iowait, irq, sirq, stolen, guest, gnice;
+    unsigned long long xtot, xbsy, xidl, xusr, xsys;
 };
 
 struct stat_data {
@@ -76,6 +77,7 @@ struct hist_sys {
 struct hist_tic {
     int id;
     int numa_node;
+    int count;
     struct stat_jifs new;
     struct stat_jifs old;
 };
@@ -159,6 +161,7 @@ setDECL(extra)                  { (void)R; (void)S; (void)T; }
 
 setDECL(TIC_ID)                 { (void)S; R->result.s_int = T->id;  }
 setDECL(TIC_NUMA_NODE)          { (void)S; R->result.s_int = T->numa_node; }
+setDECL(TIC_NUM_CONTRIBUTORS)   { (void)S; R->result.s_int = T->count; }
 
 TIC_set(TIC_USER,                 ull_int,  user)
 TIC_set(TIC_NICE,                 ull_int,  nice)
@@ -171,6 +174,12 @@ TIC_set(TIC_STOLEN,               ull_int,  stolen)
 TIC_set(TIC_GUEST,                ull_int,  guest)
 TIC_set(TIC_GUEST_NICE,           ull_int,  gnice)
 
+TIC_set(TIC_SUM_TOTAL,            ull_int,  xtot)
+TIC_set(TIC_SUM_BUSY,             ull_int,  xbsy)
+TIC_set(TIC_SUM_IDLE,             ull_int,  xidl)
+TIC_set(TIC_SUM_USER,             ull_int,  xusr)
+TIC_set(TIC_SUM_SYSTEM,           ull_int,  xsys)
+
 TICsetH(TIC_DELTA_USER,           sl_int,   user)
 TICsetH(TIC_DELTA_NICE,           sl_int,   nice)
 TICsetH(TIC_DELTA_SYSTEM,         sl_int,   system)
@@ -182,6 +191,12 @@ TICsetH(TIC_DELTA_STOLEN,         sl_int,   stolen)
 TICsetH(TIC_DELTA_GUEST,          sl_int,   guest)
 TICsetH(TIC_DELTA_GUEST_NICE,     sl_int,   gnice)
 
+TICsetH(TIC_DELTA_SUM_TOTAL,      sl_int,   xtot)
+TICsetH(TIC_DELTA_SUM_BUSY,       sl_int,   xbsy)
+TICsetH(TIC_DELTA_SUM_IDLE,       sl_int,   xidl)
+TICsetH(TIC_DELTA_SUM_USER,       sl_int,   xusr)
+TICsetH(TIC_DELTA_SUM_SYSTEM,     sl_int,   xsys)
+
 SYS_set(SYS_CTX_SWITCHES,         ul_int,   ctxt)
 SYS_set(SYS_INTERRUPTS,           ul_int,   intr)
 SYS_set(SYS_PROC_BLOCKED,         ul_int,   procs_blocked)
@@ -276,6 +291,7 @@ static struct {
 
   { RS(TIC_ID),                  QS(s_int),    TS(s_int)   },
   { RS(TIC_NUMA_NODE),           QS(s_int),    TS(s_int)   },
+  { RS(TIC_NUM_CONTRIBUTORS),    QS(s_int),    TS(s_int)   },
   { RS(TIC_USER),                QS(ull_int),  TS(ull_int) },
   { RS(TIC_NICE),                QS(ull_int),  TS(ull_int) },
   { RS(TIC_SYSTEM),              QS(ull_int),  TS(ull_int) },
@@ -287,6 +303,12 @@ static struct {
   { RS(TIC_GUEST),               QS(ull_int),  TS(ull_int) },
   { RS(TIC_GUEST_NICE),          QS(ull_int),  TS(ull_int) },
 
+  { RS(TIC_SUM_TOTAL),           QS(ull_int),  TS(ull_int) },
+  { RS(TIC_SUM_BUSY),            QS(ull_int),  TS(ull_int) },
+  { RS(TIC_SUM_IDLE),            QS(ull_int),  TS(ull_int) },
+  { RS(TIC_SUM_USER),            QS(ull_int),  TS(ull_int) },
+  { RS(TIC_SUM_SYSTEM),          QS(ull_int),  TS(ull_int) },
+
   { RS(TIC_DELTA_USER),          QS(sl_int),   TS(sl_int)  },
   { RS(TIC_DELTA_NICE),          QS(sl_int),   TS(sl_int)  },
   { RS(TIC_DELTA_SYSTEM),        QS(sl_int),   TS(sl_int)  },
@@ -298,6 +320,12 @@ static struct {
   { RS(TIC_DELTA_GUEST),         QS(sl_int),   TS(sl_int)  },
   { RS(TIC_DELTA_GUEST_NICE),    QS(sl_int),   TS(sl_int)  },
 
+  { RS(TIC_DELTA_SUM_TOTAL),     QS(sl_int),   TS(sl_int)  },
+  { RS(TIC_DELTA_SUM_BUSY),      QS(sl_int),   TS(sl_int)  },
+  { RS(TIC_DELTA_SUM_IDLE),      QS(sl_int),   TS(sl_int)  },
+  { RS(TIC_DELTA_SUM_USER),      QS(sl_int),   TS(sl_int)  },
+  { RS(TIC_DELTA_SUM_SYSTEM),    QS(sl_int),   TS(sl_int)  },
+
   { RS(SYS_CTX_SWITCHES),        QS(ul_int),   TS(ul_int)  },
   { RS(SYS_INTERRUPTS),          QS(ul_int),   TS(ul_int)  },
   { RS(SYS_PROC_BLOCKED),        QS(ul_int),   TS(ul_int)  },
@@ -385,6 +413,33 @@ static inline void stat_cleanup_stacks_all (
 } // end: stat_cleanup_stacks_all
 
 
+static inline int stat_derive_unique (
+        struct hist_tic *this)
+{
+    /* note: we exclude guest tics from xtot since ...
+             'user' already includes 'guest'
+             'nice' already includes 'gnice'
+       ( see: ./kernel/sched/cputime.c, account_guest_time ) */
+    this->new.xtot
+        = this->new.user
+        + this->new.nice
+        + this->new.system
+        + this->new.idle
+        + this->new.iowait
+        + this->new.irq
+        + this->new.sirq
+        + this->new.stolen;
+    this->new.xusr = this->new.user + this->new.nice;
+    /* this stolen guy is one i'm not sure of yet, but it's documented as:
+          "the time spent in other operating systems
+           when running in a virtualized environment"
+       so it would seem to apply to an 'involuntary wait' for a guest OS */
+    this->new.xidl = this->new.idle + this->new.iowait + this->new.stolen;
+    this->new.xbsy = this->new.xtot - this->new.xidl;
+    this->new.xsys = this->new.xbsy - this->new.xusr;
+} // end: stat_derive_unique
+
+
 static void stat_extents_free_all (
         struct ext_support *this)
 {
@@ -490,8 +545,15 @@ static int stat_make_numa_hist (
             nod_ptr->new.guest  += cpu_ptr->new.guest;  nod_ptr->old.guest  += cpu_ptr->old.guest;
             nod_ptr->new.gnice  += cpu_ptr->new.gnice;  nod_ptr->old.gnice  += cpu_ptr->old.gnice;
 
+            nod_ptr->new.xtot += cpu_ptr->new.xtot;  nod_ptr->old.xtot += cpu_ptr->old.xtot;
+            nod_ptr->new.xbsy += cpu_ptr->new.xbsy;  nod_ptr->old.xbsy += cpu_ptr->old.xbsy;
+            nod_ptr->new.xidl += cpu_ptr->new.xidl;  nod_ptr->old.xidl += cpu_ptr->old.xidl;
+            nod_ptr->new.xusr += cpu_ptr->new.xusr;  nod_ptr->old.xusr += cpu_ptr->old.xusr;
+            nod_ptr->new.xsys += cpu_ptr->new.xsys;  nod_ptr->old.xsys += cpu_ptr->old.xsys;
+
             cpu_ptr->numa_node = node;
             nod_ptr->id = node;
+            nod_ptr->count++; ;
         }
     }
     info->nodes.hist.n_inuse = info->nodes.total;
@@ -554,6 +616,7 @@ static int stat_read_failed (
         , &sum_ptr->new.sirq,  &sum_ptr->new.stolen
         , &sum_ptr->new.guest, &sum_ptr->new.gnice))
             return -1;
+    stat_derive_unique(sum_ptr);
     // let's not distort the deltas the first time thru ...
     if (!info->stat_was_read)
         memcpy(&sum_ptr->old, &sum_ptr->new, sizeof(struct stat_jifs));
@@ -568,6 +631,7 @@ reap_em_again:
         memcpy(&cpu_ptr->old, &cpu_ptr->new, sizeof(struct stat_jifs));
         // next can be overridden under 'stat_make_numa_hist'
         cpu_ptr->numa_node = STAT_NODE_INVALID;
+        cpu_ptr->count = 1;
 
         if (8 > (rc = sscanf(bp, "cpu%d %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu"
             , &cpu_ptr->id
@@ -580,6 +644,7 @@ reap_em_again:
                 cpu_ptr->id = id_sav;
                 break;                   // we must tolerate cpus taken offline
         }
+        stat_derive_unique(cpu_ptr);
         // let's not distort the deltas the first time thru ...
         if (!info->stat_was_read)
             memcpy(&cpu_ptr->old, &cpu_ptr->new, sizeof(struct stat_jifs));
@@ -595,7 +660,7 @@ reap_em_again:
         goto reap_em_again;
     }
 
-    info->cpus.total = info->cpus.hist.n_inuse = i;
+    info->cpus.total = info->cpus.hist.n_inuse = sum_ptr->count = i;
 
     // remember sys_hist stuff from last time around
     memcpy(&info->sys_hist.old, &info->sys_hist.new, sizeof(struct stat_data));

diff --git a/proc/stat.h b/proc/stat.h
index e89c64ddf94fc8692ac69e1d5aae8031e3e87caf..6151e282bc22ef6c4041a742d286445ed2398af7 100644 (file)
--- a/proc/stat.h
+++ b/proc/stat.h
@@ -29,6 +29,7 @@ enum stat_item {
 
     STAT_TIC_ID,                  //   s_int
     STAT_TIC_NUMA_NODE,           //   s_int
+    STAT_TIC_NUM_CONTRIBUTORS,    //   s_int
     STAT_TIC_USER,                // ull_int
     STAT_TIC_NICE,                // ull_int
     STAT_TIC_SYSTEM,              // ull_int
@@ -40,6 +41,12 @@ enum stat_item {
     STAT_TIC_GUEST,               // ull_int
     STAT_TIC_GUEST_NICE,          // ull_int
 
+    STAT_TIC_SUM_TOTAL,           // ull_int
+    STAT_TIC_SUM_BUSY,            // ull_int
+    STAT_TIC_SUM_IDLE,            // ull_int
+    STAT_TIC_SUM_USER,            // ull_int
+    STAT_TIC_SUM_SYSTEM,          // ull_int
+
     STAT_TIC_DELTA_USER,          //  sl_int
     STAT_TIC_DELTA_NICE,          //  sl_int
     STAT_TIC_DELTA_SYSTEM,        //  sl_int
@@ -51,6 +58,12 @@ enum stat_item {
     STAT_TIC_DELTA_GUEST,         //  sl_int
     STAT_TIC_DELTA_GUEST_NICE,    //  sl_int
 
+    STAT_TIC_DELTA_SUM_TOTAL,     //  sl_int
+    STAT_TIC_DELTA_SUM_BUSY,      //  sl_int
+    STAT_TIC_DELTA_SUM_IDLE,      //  sl_int
+    STAT_TIC_DELTA_SUM_USER,      //  sl_int
+    STAT_TIC_DELTA_SUM_SYSTEM,    //  sl_int
+
     STAT_SYS_CTX_SWITCHES,        //  ul_int
     STAT_SYS_INTERRUPTS,          //  ul_int
     STAT_SYS_PROC_BLOCKED,        //  ul_int