tuna: Adapt show_threads cgroup output to terminal size

Passing the --cgroup flag to the show_threads command currently displays
long cgroup strings on the thread output and decreases readability.

Adapt the show_threads output to account for output string and terminal
size, and format output accordingly to improve readability. Add
--spaced flag to show_threads to print cgroups with spacing in
between thread outputs.

Signed-off-by: Leah Leshchinsky <lleshchi@redhat.com>

---
target branch: main

Signed-off-by: John Kacur <jkacur@redhat.com>

2 files changed, 30 insertions, 11 deletions

diff --git a/docs/tuna.8 b/docs/tuna.8
index f50a8c2..2423894 100644
--- a/docs/tuna.8
+++ b/docs/tuna.8
@@ -188,6 +188,7 @@ optional arguments:
                         Operation will affect children threads
   -G, --cgroups         Display the processes with the type of cgroups they
                         are in
+  -z, --spaced          Display spaced view for cgroups
 
 .TP
 \fBtuna show_irqs\fR
diff --git a/tuna-cmd.py b/tuna-cmd.py
index 8be35f7..630c8bc 100755
--- a/tuna-cmd.py
+++ b/tuna-cmd.py
@@ -114,6 +114,7 @@ def gen_parser():
             "sockets": dict(dest='cpu_list', default=[], metavar='CPU-SOCKET-LIST', type=socketstring_to_list, help="CPU-SOCKET-LIST affected by commands"),
             "show_sockets": dict(action='store_true', help='Show network sockets in use by threads'),
             "cgroups": dict(action='store_true', dest='cgroups', help='Display the processes with the type of cgroups they are in'),
+            "spaced": dict(action='store_false', dest='compact', help='Display spaced view for cgroups'),
             "affect_children": dict(action='store_true', help="Operation will affect children threads"),
             "nohz_full": dict(action='store_true', help="CPUs in nohz_full kernel command line will be affected by operations"),
             "no_uthreads": dict(action='store_false', dest='uthreads', help="Operations will not affect user threads"),
@@ -215,6 +216,7 @@ def gen_parser():
     if have_inet_diag:
         show_threads.add_argument('-n', '--show_sockets', **MODS['show_sockets'])
     show_threads.add_argument('-G', '--cgroups', **MODS['cgroups'])
+    show_threads.add_argument('-z', '--spaced', **MODS['spaced'])
 
 
     show_irqs_group = show_irqs.add_mutually_exclusive_group(required=False)
@@ -335,7 +337,7 @@ def format_affinity(affinity):
     return ",".join(str(hex(a)) for a in procfs.hexbitmask(affinity, get_nr_cpus()))
 
 def ps_show_thread(pid, affect_children, ps, has_ctxt_switch_info, sock_inodes,
-                   sock_inode_re, cgroups):
+                   sock_inode_re, cgroups, columns=None, compact=True):
     global irqs
     try:
         affinity = format_affinity(os.sched_getaffinity(pid))
@@ -372,10 +374,20 @@ def ps_show_thread(pid, affect_children, ps, has_ctxt_switch_info, sock_inodes,
                                           nonvoluntary_ctxt_switches)
 
     # Indent affected children
-    print(" %-5d " % pid if affect_children else "  %-5d" % pid, end=' ')
-    print("%6s %5d %8s%s %15s %s" % (sched, rtprio, affinity,
-                                     ctxt_switch_info, cmd, users), end=' ')
-    print(" %9s" % cgout if cgroups else "")
+    s1 = " %-5d " % pid if affect_children else "  %-5d" % pid
+    print(s1, end=' ')
+    s2 = "%6s %5d %8s%s %15s     %s" % (sched, rtprio, affinity,
+                                     ctxt_switch_info, cmd, users)
+    print(s2, end=' ')
+
+    if cgroups:
+        length = int(columns) - len(s1 + " ") - len(s2 + " ")
+        if len(" %9s" % cgout) <= length:
+            print("%s" % cgout)
+        else:
+            print("\n %s" % cgout + ("" if compact else "\n"))
+    else:
+        print()
 
     if sock_inodes:
         ps_show_sockets(pid, ps, sock_inodes, sock_inode_re,
@@ -384,12 +396,12 @@ def ps_show_thread(pid, affect_children, ps, has_ctxt_switch_info, sock_inodes,
         for tid in list(ps[pid]["threads"].keys()):
             ps_show_thread(tid, False, ps[pid]["threads"],
                            has_ctxt_switch_info,
-                           sock_inodes, sock_inode_re, cgroups)
+                           sock_inodes, sock_inode_re, cgroups, columns, compact)
 
 
 def ps_show(ps, affect_children, thread_list, cpu_list,
             irq_list_numbers, show_uthreads, show_kthreads,
-            has_ctxt_switch_info, sock_inodes, sock_inode_re, cgroups):
+            has_ctxt_switch_info, sock_inodes, sock_inode_re, cgroups, compact):
 
     ps_list = []
     for pid in list(ps.keys()):
@@ -426,9 +438,15 @@ def ps_show(ps, affect_children, thread_list, cpu_list,
 
     ps_list.sort()
 
+
+    # Width of terminal in columns
+    columns = None
+    if cgroups:
+        _, columns = os.popen('stty size', 'r').read().split()
+
     for pid in ps_list:
         ps_show_thread(pid, affect_children, ps, has_ctxt_switch_info,
-                       sock_inodes, sock_inode_re, cgroups)
+                       sock_inodes, sock_inode_re, cgroups, columns, compact)
 
 
 def load_socktype(socktype, inodes):
@@ -449,7 +467,7 @@ def load_sockets():
 
 
 def do_ps(thread_list, cpu_list, irq_list, show_uthreads, show_kthreads,
-          affect_children, show_sockets, cgroups):
+          affect_children, show_sockets, cgroups, compact):
     ps = procfs.pidstats()
     if affect_children:
         ps.reload_threads()
@@ -466,7 +484,7 @@ def do_ps(thread_list, cpu_list, irq_list, show_uthreads, show_kthreads,
             ps_show_header(has_ctxt_switch_info, cgroups)
         ps_show(ps, affect_children, thread_list,
                 cpu_list, irq_list, show_uthreads, show_kthreads,
-                has_ctxt_switch_info, sock_inodes, sock_inode_re, cgroups)
+                has_ctxt_switch_info, sock_inodes, sock_inode_re, cgroups, compact)
     except IOError:
         # 'tuna -P | head' for instance
         pass
@@ -698,7 +716,7 @@ def main():
 
     elif args.command in ['show_threads']:
         do_ps(args.thread_list, args.cpu_list, args.irq_list, args.uthreads,
-                args.kthreads, args.affect_children, args.show_sockets if "show_sockets" in args else None, args.cgroups)
+                args.kthreads, args.affect_children, args.show_sockets if "show_sockets" in args else None, args.cgroups, args.compact)
 
     elif args.command in ['show_irqs']:
         show_irqs(args.irq_list, args.cpu_list)