Add columns for process autogroup identifier and nice value

Adds AGRP (autogroup) and ANI (autogroup nice) columns that
report the information from /proc/PID/autogroup, as well as
handlers for '{' and '}' to change the autogroup nice value.

This is guarded by /proc/sys/kernel/sched_autogroup_enabled
such that sampling and/or changing values wont be attempted
unless the kernel feature is enabled.

Fixes: #720

13 files changed, 201 insertions, 10 deletions

diff --git a/htop.1.in b/htop.1.in
index 9b81a210..5d00c7cb 100644
--- a/htop.1.in
+++ b/htop.1.in
@@ -176,6 +176,13 @@ This can only be done by the superuser.
 .B F8, [
 Decrease the selected process's priority (add to 'nice' value)
 .TP
+.B }
+Increase the selected process's autogroup priority (subtract from autogroup 'nice' value).
+This can only be done by the superuser.
+.TP
+.B {
+Decrease the selected process's autogroup priority (add to autogroup 'nice' value)
+.TP
 .B F9, k
 "Kill" process: sends a signal which is selected in a menu, to one or a group
 of processes. If processes were tagged, sends the signal to all tagged processes.
@@ -484,6 +491,12 @@ The command name for the process. Requires Linux kernel 2.6.33 or newer.
 .B EXE
 The executable file of the process as reported by the kernel. Requires CAP_SYS_PTRACE and PTRACE_MODE_READ_FSCRED.
 .TP
+.B AGRP
+The autogroup identifier for the process. Requires Linux CFS to be enabled.
+.TP
+.B ANI
+The autogroup nice value for the process autogroup. Requires Linux CFS to be enabled.
+.TP
 .B All other flags
 Currently unsupported (always displays '-').
 .SH "EXTERNAL LIBRARIES"
diff --git a/linux/LinuxProcess.c b/linux/LinuxProcess.c
index fe8492df..c353f8a7 100644
--- a/linux/LinuxProcess.c
+++ b/linux/LinuxProcess.c
@@ -100,6 +100,8 @@ const ProcessFieldData Process_fields[LAST_PROCESSFIELD] = {
    [PROC_COMM] = { .name = "COMM", .title = "COMM            ", .description = "comm string of the process from /proc/[pid]/comm", .flags = 0, },
    [PROC_EXE] = { .name = "EXE", .title = "EXE             ", .description = "Basename of exe of the process from /proc/[pid]/exe", .flags = 0, },
    [CWD] = { .name = "CWD", .title = "CWD                       ", .description = "The current working directory of the process", .flags = PROCESS_FLAG_CWD, },
+   [AUTOGROUP_ID] = { .name = "AUTOGROUP_ID", .title = "AGRP", .description = "The autogroup identifier of the process", .flags = PROCESS_FLAG_LINUX_AUTOGROUP, },
+   [AUTOGROUP_NICE] = { .name = "AUTOGROUP_NICE", .title = " ANI", .description = "Nice value (the higher the value, the more other processes take priority) associated with the process autogroup", .flags = PROCESS_FLAG_LINUX_AUTOGROUP, },
 };
 
 Process* LinuxProcess_new(const Settings* settings) {
@@ -159,6 +161,37 @@ bool LinuxProcess_setIOPriority(Process* this, Arg ioprio) {
    return (LinuxProcess_updateIOPriority((LinuxProcess*)this) == ioprio.i);
 }
 
+bool LinuxProcess_isAutogroupEnabled(void) {
+   char buf[16];
+   if (xReadfile(PROCDIR "/sys/kernel/sched_autogroup_enabled", buf, sizeof(buf)) < 0)
+      return false;
+   return buf[0] == '1';
+}
+
+bool LinuxProcess_changeAutogroupPriorityBy(Process* this, Arg delta) {
+   char buffer[256];
+   xSnprintf(buffer, sizeof(buffer), PROCDIR "/%d/autogroup", this->pid);
+
+   FILE* file = fopen(buffer, "r+");
+   if (!file)
+      return false;
+
+   long int identity;
+   int nice;
+   int ok = fscanf(file, "/autogroup-%ld nice %d", &identity, &nice);
+   bool success;
+   if (ok == 2) {
+      rewind(file);
+      xSnprintf(buffer, sizeof(buffer), "%d", nice + delta.i);
+      success = fputs(buffer, file) > 0;
+   } else {
+      success = false;
+   }
+
+   fclose(file);
+   return success;
+}
+
 #ifdef HAVE_DELAYACCT
 static void LinuxProcess_printDelay(float delay_percent, char* buffer, int n) {
    if (isnan(delay_percent)) {
@@ -259,6 +292,25 @@ static void LinuxProcess_writeField(const Process* this, RichString* str, Proces
       xSnprintf(buffer, n, "%5lu ", lp->ctxt_diff);
       break;
    case SECATTR: snprintf(buffer, n, "%-30s   ", lp->secattr ? lp->secattr : "?"); break;
+   case AUTOGROUP_ID:
+      if (lp->autogroup_id != -1) {
+         xSnprintf(buffer, n, "%4ld ", lp->autogroup_id);
+      } else {
+         attr = CRT_colors[PROCESS_SHADOW];
+         xSnprintf(buffer, n, " N/A ");
+      }
+      break;
+   case AUTOGROUP_NICE:
+      if (lp->autogroup_id != -1) {
+         xSnprintf(buffer, n, "%3d ", lp->autogroup_nice);
+         attr = lp->autogroup_nice < 0 ? CRT_colors[PROCESS_HIGH_PRIORITY]
+              : lp->autogroup_nice > 0 ? CRT_colors[PROCESS_LOW_PRIORITY]
+              : CRT_colors[PROCESS_SHADOW];
+      } else {
+         attr = CRT_colors[PROCESS_SHADOW];
+         xSnprintf(buffer, n, "N/A ");
+      }
+      break;
    default:
       Process_writeField(this, str, field);
       return;
@@ -350,6 +402,10 @@ static int LinuxProcess_compareByKey(const Process* v1, const Process* v2, Proce
       return SPACESHIP_NUMBER(p1->ctxt_diff, p2->ctxt_diff);
    case SECATTR:
       return SPACESHIP_NULLSTR(p1->secattr, p2->secattr);
+   case AUTOGROUP_ID:
+      return SPACESHIP_NUMBER(p1->autogroup_id, p2->autogroup_id);
+   case AUTOGROUP_NICE:
+      return SPACESHIP_NUMBER(p1->autogroup_nice, p2->autogroup_nice);
    default:
       return Process_compareByKey_Base(v1, v2, key);
    }
diff --git a/linux/LinuxProcess.h b/linux/LinuxProcess.h
index 5f77db2e..bca5247a 100644
--- a/linux/LinuxProcess.h
+++ b/linux/LinuxProcess.h
@@ -28,6 +28,7 @@ in the source distribution for its full text.
 #define PROCESS_FLAG_LINUX_SECATTR   0x00008000
 #define PROCESS_FLAG_LINUX_LRS_FIX   0x00010000
 #define PROCESS_FLAG_LINUX_DELAYACCT 0x00040000
+#define PROCESS_FLAG_LINUX_AUTOGROUP 0x00080000
 
 typedef struct LinuxProcess_ {
    Process super;
@@ -99,6 +100,10 @@ typedef struct LinuxProcess_ {
    unsigned long ctxt_diff;
    char* secattr;
    unsigned long long int last_mlrs_calctime;
+
+   /* Autogroup scheduling (CFS) information */
+   long int autogroup_id;
+   int autogroup_nice;
 } LinuxProcess;
 
 extern int pageSize;
@@ -117,6 +122,10 @@ IOPriority LinuxProcess_updateIOPriority(LinuxProcess* this);
 
 bool LinuxProcess_setIOPriority(Process* this, Arg ioprio);
 
+bool LinuxProcess_isAutogroupEnabled(void);
+
+bool LinuxProcess_changeAutogroupPriorityBy(Process* this, Arg delta);
+
 bool Process_isThread(const Process* this);
 
 #endif
diff --git a/linux/LinuxProcessList.c b/linux/LinuxProcessList.c
index e1b923d6..d3463b51 100644
--- a/linux/LinuxProcessList.c
+++ b/linux/LinuxProcessList.c
@@ -909,6 +909,23 @@ static void LinuxProcessList_readOomData(LinuxProcess* process, openat_arg_t pro
    fclose(file);
 }
 
+static void LinuxProcessList_readAutogroup(LinuxProcess* process, openat_arg_t procFd) {
+   process->autogroup_id = -1;
+
+   char autogroup[64]; // space for two numeric values and fixed length strings
+   ssize_t amtRead = xReadfileat(procFd, "autogroup", autogroup, sizeof(autogroup));
+   if (amtRead < 0)
+      return;
+
+   long int identity;
+   int nice;
+   int ok = sscanf(autogroup, "/autogroup-%ld nice %d", &identity, &nice);
+   if (ok == 2) {
+      process->autogroup_id = identity;
+      process->autogroup_nice = nice;
+   }
+}
+
 static void LinuxProcessList_readCtxtData(LinuxProcess* process, openat_arg_t procFd) {
    FILE* file = fopenat(procFd, "status", "r");
    if (!file)
@@ -1521,6 +1538,10 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, openat_arg_
          LinuxProcessList_readCwd(lp, procFd);
       }
 
+      if ((settings->flags & PROCESS_FLAG_LINUX_AUTOGROUP) && this->haveAutogroup) {
+         LinuxProcessList_readAutogroup(lp, procFd);
+      }
+
       if (proc->state == 'Z' && !proc->cmdline && statCommand[0]) {
          Process_updateCmdline(proc, statCommand, 0, strlen(statCommand));
       } else if (Process_isThread(proc)) {
@@ -2071,6 +2092,16 @@ void ProcessList_goThroughEntries(ProcessList* super, bool pauseProcessUpdate) {
       return;
    }
 
+   if (settings->flags & PROCESS_FLAG_LINUX_AUTOGROUP) {
+      // Refer to sched(7) 'autogroup feature' section
+      // The kernel feature can be enabled/disabled through procfs at
+      // any time, so check for it at the start of each sample - only
+      // read from per-process procfs files if it's globally enabled.
+      this->haveAutogroup = LinuxProcess_isAutogroupEnabled();
+   } else {
+      this->haveAutogroup = false;
+   }
+
    /* PROCDIR is an absolute path */
    assert(PROCDIR[0] == '/');
 #ifdef HAVE_OPENAT
diff --git a/linux/LinuxProcessList.h b/linux/LinuxProcessList.h
index 2f296eca..0d1ad48c 100644
--- a/linux/LinuxProcessList.h
+++ b/linux/LinuxProcessList.h
@@ -71,6 +71,7 @@ typedef struct LinuxProcessList_ {
 
    TtyDriver* ttyDrivers;
    bool haveSmapsRollup;
+   bool haveAutogroup;
 
    #ifdef HAVE_DELAYACCT
    struct nl_sock* netlink_socket;
diff --git a/linux/Platform.c b/linux/Platform.c
index d23bf57d..64be93c7 100644
--- a/linux/Platform.c
+++ b/linux/Platform.c
@@ -150,8 +150,38 @@ static Htop_Reaction Platform_actionSetIOPriority(State* st) {
    return HTOP_REFRESH | HTOP_REDRAW_BAR | HTOP_UPDATE_PANELHDR;
 }
 
+static bool Platform_changeAutogroupPriority(MainPanel* panel, int delta) {
+   if (LinuxProcess_isAutogroupEnabled() == false) {
+      beep();
+      return false;
+   }
+   bool anyTagged;
+   bool ok = MainPanel_foreachProcess(panel, LinuxProcess_changeAutogroupPriorityBy, (Arg) { .i = delta }, &anyTagged);
+   if (!ok)
+      beep();
+   return anyTagged;
+}
+
+static Htop_Reaction Platform_actionHigherAutogroupPriority(State* st) {
+   if (Settings_isReadonly())
+      return HTOP_OK;
+
+   bool changed = Platform_changeAutogroupPriority(st->mainPanel, -1);
+   return changed ? HTOP_REFRESH : HTOP_OK;
+}
+
+static Htop_Reaction Platform_actionLowerAutogroupPriority(State* st) {
+   if (Settings_isReadonly())
+      return HTOP_OK;
+
+   bool changed = Platform_changeAutogroupPriority(st->mainPanel, 1);
+   return changed ? HTOP_REFRESH : HTOP_OK;
+}
+
 void Platform_setBindings(Htop_Action* keys) {
    keys['i'] = Platform_actionSetIOPriority;
+   keys['{'] = Platform_actionLowerAutogroupPriority;
+   keys['}'] = Platform_actionHigherAutogroupPriority;
 }
 
 const MeterClass* const Platform_meterTypes[] = {
diff --git a/linux/ProcessField.h b/linux/ProcessField.h
index c8d24c0b..d109ff9d 100644
--- a/linux/ProcessField.h
+++ b/linux/ProcessField.h
@@ -44,8 +44,8 @@ in the source distribution for its full text.
    M_PSSWP = 121,                \
    CTXT = 122,                   \
    SECATTR = 123,                \
-                                 \
-   DUMMY_BUMP_FIELD = CWD,       \
+   AUTOGROUP_ID = 127,           \
+   AUTOGROUP_NICE = 128,         \
    // End of list
 
 
diff --git a/pcp/PCPProcess.c b/pcp/PCPProcess.c
index 993a746f..de709110 100644
--- a/pcp/PCPProcess.c
+++ b/pcp/PCPProcess.c
@@ -82,6 +82,8 @@ const ProcessFieldData Process_fields[] = {
    [PROC_COMM] = { .name = "COMM", .title = "COMM            ", .description = "comm string of the process", .flags = 0, },
    [PROC_EXE] = { .name = "EXE", .title = "EXE             ", .description = "Basename of exe of the process", .flags = 0, },
    [CWD] = { .name = "CWD", .title = "CWD                       ", .description = "The current working directory of the process", .flags = PROCESS_FLAG_CWD, },
+   [AUTOGROUP_ID] = { .name = "AUTOGROUP_ID", .title = "AGRP", .description = "The autogroup identifier of the process", .flags = PROCESS_FLAG_LINUX_AUTOGROUP, },
+   [AUTOGROUP_NICE] = { .name = "AUTOGROUP_NICE", .title = " ANI", .description = "Nice value (the higher the value, the more other processes take priority) associated with the process autogroup", .flags = PROCESS_FLAG_LINUX_AUTOGROUP, },
 };
 
 Process* PCPProcess_new(const Settings* settings) {
@@ -168,6 +170,25 @@ static void PCPProcess_writeField(const Process* this, RichString* str, ProcessF
       xSnprintf(buffer, n, "%5lu ", pp->ctxt_diff);
       break;
    case SECATTR: snprintf(buffer, n, "%-30s   ", pp->secattr ? pp->secattr : "?"); break;
+   case AUTOGROUP_ID:
+      if (pp->autogroup_id != -1) {
+         xSnprintf(buffer, n, "%4ld ", pp->autogroup_id);
+      } else {
+         attr = CRT_colors[PROCESS_SHADOW];
+         xSnprintf(buffer, n, " N/A ");
+      }
+      break;
+   case AUTOGROUP_NICE:
+      if (pp->autogroup_id != -1) {
+         xSnprintf(buffer, n, "%3d ", pp->autogroup_nice);
+         attr = pp->autogroup_nice < 0 ? CRT_colors[PROCESS_HIGH_PRIORITY]
+              : pp->autogroup_nice > 0 ? CRT_colors[PROCESS_LOW_PRIORITY]
+              : CRT_colors[PROCESS_SHADOW];
+      } else {
+         attr = CRT_colors[PROCESS_SHADOW];
+         xSnprintf(buffer, n, "N/A ");
+      }
+      break;
    default:
       Process_writeField(this, str, field);
       return;
@@ -245,6 +266,10 @@ static int PCPProcess_compareByKey(const Process* v1, const Process* v2, Process
       return SPACESHIP_NUMBER(p1->ctxt_diff, p2->ctxt_diff);
    case SECATTR:
       return SPACESHIP_NULLSTR(p1->secattr, p2->secattr);
+   case AUTOGROUP_ID:
+      return SPACESHIP_NUMBER(p1->autogroup_id, p2->autogroup_id);
+   case AUTOGROUP_NICE:
+      return SPACESHIP_NUMBER(p1->autogroup_nice, p2->autogroup_nice);
    default:
       return Process_compareByKey_Base(v1, v2, key);
    }
diff --git a/pcp/PCPProcess.h b/pcp/PCPProcess.h
index 25707f2b..2d1a8b6c 100644
--- a/pcp/PCPProcess.h
+++ b/pcp/PCPProcess.h
@@ -20,11 +20,12 @@ in the source distribution for its full text.
 #include "Settings.h"
 
 
-#define PROCESS_FLAG_LINUX_CGROUP   0x0800
-#define PROCESS_FLAG_LINUX_OOM      0x1000
-#define PROCESS_FLAG_LINUX_SMAPS    0x2000
-#define PROCESS_FLAG_LINUX_CTXT     0x4000
-#define PROCESS_FLAG_LINUX_SECATTR  0x8000
+#define PROCESS_FLAG_LINUX_CGROUP    0x00000800
+#define PROCESS_FLAG_LINUX_OOM       0x00001000
+#define PROCESS_FLAG_LINUX_SMAPS     0x00002000
+#define PROCESS_FLAG_LINUX_CTXT      0x00004000
+#define PROCESS_FLAG_LINUX_SECATTR   0x00008000
+#define PROCESS_FLAG_LINUX_AUTOGROUP 0x00080000
 
 typedef struct PCPProcess_ {
    Process super;
@@ -70,6 +71,8 @@ typedef struct PCPProcess_ {
    double io_rate_read_bps;
    double io_rate_write_bps;
    char* cgroup;
+   long int autogroup_id;
+   int autogroup_nice;
    unsigned int oom;
    unsigned long long int delay_read_time;
    unsigned long long cpu_delay_total;
diff --git a/pcp/PCPProcessList.c b/pcp/PCPProcessList.c
index ae974435..b0fe7666 100644
--- a/pcp/PCPProcessList.c
+++ b/pcp/PCPProcessList.c
@@ -89,13 +89,20 @@ void ProcessList_delete(ProcessList* pl) {
    free(this);
 }
 
-static inline unsigned long Metric_instance_s32(int metric, int pid, int offset, unsigned long fallback) {
+static inline long Metric_instance_s32(int metric, int pid, int offset, long fallback) {
    pmAtomValue value;
    if (Metric_instance(metric, pid, offset, &value, PM_TYPE_32))
       return value.l;
    return fallback;
 }
 
+static inline long long Metric_instance_s64(int metric, int pid, int offset, long long fallback) {
+   pmAtomValue value;
+   if (Metric_instance(metric, pid, offset, &value, PM_TYPE_64))
+      return value.l;
+   return fallback;
+}
+
 static inline unsigned long Metric_instance_u32(int metric, int pid, int offset, unsigned long fallback) {
    pmAtomValue value;
    if (Metric_instance(metric, pid, offset, &value, PM_TYPE_U32))
@@ -222,6 +229,11 @@ static void PCPProcessList_readOomData(PCPProcess* pp, int pid, int offset) {
    pp->oom = Metric_instance_u32(PCP_PROC_OOMSCORE, pid, offset, 0);
 }
 
+static void PCPProcessList_readAutogroup(PCPProcess* pp, int pid, int offset) {
+   pp->autogroup_id = Metric_instance_s64(PCP_PROC_AUTOGROUP_ID, pid, offset, -1);
+   pp->autogroup_nice = Metric_instance_s32(PCP_PROC_AUTOGROUP_NICE, pid, offset, 0);
+}
+
 static void PCPProcessList_readCtxtData(PCPProcess* pp, int pid, int offset) {
    pmAtomValue value;
    unsigned long ctxt = 0;
@@ -403,6 +415,9 @@ static bool PCPProcessList_updateProcesses(PCPProcessList* this, double period,
       if (settings->flags & PROCESS_FLAG_CWD)
          PCPProcessList_readCwd(pp, pid, offset);
 
+      if (settings->flags & PROCESS_FLAG_LINUX_AUTOGROUP)
+         PCPProcessList_readAutogroup(pp, pid, offset);
+
       if (proc->state == 'Z' && !proc->cmdline && command[0]) {
          Process_updateCmdline(proc, command, 0, strlen(command));
       } else if (Process_isThread(proc)) {
@@ -651,6 +666,9 @@ void ProcessList_goThroughEntries(ProcessList* super, bool pauseProcessUpdate) {
    Metric_enable(PCP_PROC_NVCTXSW, flagged && enabled);
    flagged = settings->flags & PROCESS_FLAG_LINUX_SECATTR;
    Metric_enable(PCP_PROC_LABELS, flagged && enabled);
+   flagged = settings->flags & PROCESS_FLAG_LINUX_AUTOGROUP;
+   Metric_enable(PCP_PROC_AUTOGROUP_ID, flagged && enabled);
+   Metric_enable(PCP_PROC_AUTOGROUP_NICE, flagged && enabled);
 
    /* Sample smaps metrics on every second pass to improve performance */
    static int smaps_flag;
diff --git a/pcp/Platform.c b/pcp/Platform.c
index 4ddf7e68..63ff50a7 100644
--- a/pcp/Platform.c
+++ b/pcp/Platform.c
@@ -224,6 +224,8 @@ static const char* Platform_metricNames[] = {
    [PCP_PROC_TTYNAME] = "proc.psinfo.ttyname",
    [PCP_PROC_EXE] = "proc.psinfo.exe",
    [PCP_PROC_CWD] = "proc.psinfo.cwd",
+   [PCP_PROC_AUTOGROUP_ID] = "proc.autogroup.id",
+   [PCP_PROC_AUTOGROUP_NICE] = "proc.autogroup.nice",
    [PCP_PROC_ID_UID] = "proc.id.uid",
    [PCP_PROC_ID_USER] = "proc.id.uid_nm",
    [PCP_PROC_IO_RCHAR] = "proc.io.rchar",
diff --git a/pcp/Platform.h b/pcp/Platform.h
index 6b0215c8..527bef29 100644
--- a/pcp/Platform.h
+++ b/pcp/Platform.h
@@ -210,6 +210,9 @@ typedef enum Metric_ {
    PCP_PROC_EXE,                /* proc.psinfo.exe */
    PCP_PROC_CWD,                /* proc.psinfo.cwd */
 
+   PCP_PROC_AUTOGROUP_ID,       /* proc.autogroup.id */
+   PCP_PROC_AUTOGROUP_NICE,     /* proc.autogroup.nice */
+
    PCP_PROC_ID_UID,             /* proc.id.uid */
    PCP_PROC_ID_USER,            /* proc.id.uid_nm */
 
diff --git a/pcp/ProcessField.h b/pcp/ProcessField.h
index 3d5cb743..979addc0 100644
--- a/pcp/ProcessField.h
+++ b/pcp/ProcessField.h
@@ -43,8 +43,8 @@ in the source distribution for its full text.
    M_PSSWP = 121,                \
    CTXT = 122,                   \
    SECATTR = 123,                \
-                                 \
-   DUMMY_BUMP_FIELD = CWD,       \
+   AUTOGROUP_ID = 127,           \
+   AUTOGROUP_NICE = 128,         \
    // End of list