[PATCH 1/7] tuna: Add --show-system flag to filter systemd cpusets

Add ability to filter out systemd-managed cpusets from cpuset list
and status commands. By default, system cpusets (.slice, .scope,
.mount, .service) are now hidden as they are not relevant for RT
tuning. Users can show them with --show-system flag.

Changes:
- Add skip_system parameter to get_all_cpusets_info()
- Add --show-system flag to 'cpuset list' and 'cpuset status'
- Refactor cpuset_list() to use centralized get_all_cpusets_info()
- Simplify blocklist checking to reuse data from get_all_cpusets_info()

This prepares for cpuset save/restore where we only want to save
user-created cpusets, not systemd infrastructure.

Assisted-by: Claude:claude-sonnet-4-5
Signed-off-by: John Kacur <[email protected]>
---
 tuna-cmd.py | 114 ++++++++++++++++------------------------------------
 1 file changed, 35 insertions(+), 79 deletions(-)

diff --git a/tuna-cmd.py b/tuna-cmd.py
index 25257c465532..262159150211 100755
--- a/tuna-cmd.py
+++ b/tuna-cmd.py
@@ -292,6 +292,7 @@ def gen_parser():
     cpuset_list.add_argument('-p', '--pattern', type=str, metavar='PATTERN', help='Filter by glob pattern (e.g., tuna*)')
     cpuset_list.add_argument('-v', '--verbose', action='store_true', help='Show detailed information (CPUs, tasks, partition type)')
     cpuset_list.add_argument('--show-empty', action='store_true', help='Include cpusets with no CPUs assigned (default: skip empty)')
+    cpuset_list.add_argument('--show-system', action='store_true', help='Include systemd-managed cpusets (default: skip system)')
     cpuset_list.add_argument('--no-recursive', dest='recursive', action='store_false', default=True, help='Only search top-level cpusets')
 
     # cpuset destroy
@@ -317,6 +318,7 @@ def gen_parser():
     cpuset_status = cpuset_subparser.add_parser('status', description='Show system-wide cpuset overview', help='Show cpuset status')
     cpuset_status.add_argument('-p', '--pattern', type=str, metavar='PATTERN', help='Filter by glob pattern (e.g., tuna*)')
     cpuset_status.add_argument('--show-empty', action='store_true', help='Include cpusets with no CPUs assigned (default: skip empty)')
+    cpuset_status.add_argument('--show-system', action='store_true', help='Include systemd-managed cpusets (default: skip system)')
     cpuset_status.add_argument('--no-recursive', dest='recursive', action='store_false', default=True, help='Only show top-level cpusets')
 
     # cpuset modify
@@ -984,13 +986,14 @@ def get_cpuset_info(cpuset_name):
     return info
 
 
-def get_all_cpusets_info(pattern=None, recursive=True, skip_empty=False):
+def get_all_cpusets_info(pattern=None, recursive=True, skip_empty=False, skip_system=False):
     """Get information about all cpusets matching criteria.
 
     Args:
         pattern: Glob pattern to filter cpusets (None for all)
         recursive: If True, search nested cpusets
         skip_empty: If True, skip cpusets with no CPUs assigned
+        skip_system: If True, skip systemd-managed cpusets (.slice, .scope, .mount, .service)
 
     Returns:
         list: List of cpuset info dictionaries (from get_cpuset_info)
@@ -998,6 +1001,9 @@ def get_all_cpusets_info(pattern=None, recursive=True, skip_empty=False):
     cpusets = cpuset.list_cpusets(pattern=pattern, recursive=recursive)
     infos = []
 
+    # System cpuset suffixes to filter
+    system_suffixes = ('.slice', '.scope', '.mount', '.service')
+
     for cs_name in cpusets:
         info = get_cpuset_info(cs_name)
 
@@ -1005,6 +1011,10 @@ def get_all_cpusets_info(pattern=None, recursive=True, skip_empty=False):
         if skip_empty and not info['cpus']:
             continue
 
+        # Skip system cpusets if requested
+        if skip_system and cs_name.endswith(system_suffixes):
+            continue
+
         infos.append(info)
 
     return infos
@@ -1056,13 +1066,14 @@ def cpuset_create(cpu_list, name, isolated, memory_nodes=None):
         sys.exit(1)
 
 
-def cpuset_list(pattern, verbose, show_empty, recursive):
+def cpuset_list(pattern, verbose, show_empty, show_system, recursive):
     """Handler for 'tuna cpuset list' command.
 
     Args:
         pattern: Glob pattern to filter cpusets (None for all)
         verbose: If True, show detailed info (CPUs, memory nodes, tasks, partition)
         show_empty: If True, show cpusets with no CPUs assigned (default: skip empty)
+        show_system: If True, show systemd-managed cpusets (default: skip system)
         recursive: If True, search nested cpusets
     """
     # Check cgroup v2 support
@@ -1071,25 +1082,11 @@ def cpuset_list(pattern, verbose, show_empty, recursive):
         print("Error: cgroup v2 cpusets not supported on this system", file=sys.stderr)
         sys.exit(1)
 
-    # List cpusets
-    cpusets = cpuset.list_cpusets(pattern=pattern, recursive=recursive)
-
-    # Filter out empty cpusets unless --show-empty was specified
-    if not show_empty:
-        filtered_cpusets = []
-        for cs_name in cpusets:
-            cs_path = os.path.join('/sys/fs/cgroup', cs_name)
-            try:
-                with open(os.path.join(cs_path, 'cpuset.cpus'), 'r', encoding='utf-8') as f:
-                    cpus = f.read().strip()
-                    if cpus:  # Only include if CPUs are assigned
-                        filtered_cpusets.append(cs_name)
-            except (OSError, IOError):
-                # If we can't read it, skip it
-                pass
-        cpusets = filtered_cpusets
+    # Get cpuset info using centralized function (skip_* params are inverse of show_*)
+    infos = get_all_cpusets_info(pattern=pattern, recursive=recursive,
+                                  skip_empty=not show_empty, skip_system=not show_system)
 
-    if not cpusets:
+    if not infos:
         if pattern:
             print(f"No cpusets found matching pattern '{pattern}'")
         else:
@@ -1101,64 +1098,21 @@ def cpuset_list(pattern, verbose, show_empty, recursive):
         print(f"{'NAME':<20} {'CPUS':<15} {'MEMS':<10} {'TASKS':<7} {'PARTITION':<10}")
         print("-" * 65)
 
-        for cs_name in cpusets:
-            cs_path = os.path.join('/sys/fs/cgroup', cs_name)
-
-            try:
-                # Read CPUs
-                with open(os.path.join(cs_path, 'cpuset.cpus'), 'r', encoding='utf-8') as f:
-                    cpus = f.read().strip() or "(none)"
-
-                # Read memory nodes
-                with open(os.path.join(cs_path, 'cpuset.mems'), 'r', encoding='utf-8') as f:
-                    mems = f.read().strip() or "(none)"
-
-                # Read tasks count
-                with open(os.path.join(cs_path, 'cgroup.procs'), 'r', encoding='utf-8') as f:
-                    tasks = [line.strip() for line in f if line.strip()]
-                    task_count = len(tasks)
-
-                # Read partition type (if available)
-                partition_file = os.path.join(cs_path, 'cpuset.cpus.partition')
-                if os.path.exists(partition_file):
-                    with open(partition_file, 'r', encoding='utf-8') as f:
-                        partition = f.read().strip()
-                else:
-                    partition = "n/a"
-
-                print(f"{cs_name:<20} {cpus:<15} {mems:<10} {task_count:<7} {partition:<10}")
-
-            except (OSError, IOError) as e:
-                print(f"{cs_name:<20} (error reading: {e})", file=sys.stderr)
+        for info in infos:
+            cpus = info['cpus'] or "(none)"
+            mems = info['mems'] or "(none)"
+            print(f"{info['name']:<20} {cpus:<15} {mems:<10} {info['task_count']:<7} {info['partition']:<10}")
     else:
         # Simple output: just names
-        for cs_name in cpusets:
-            print(cs_name)
+        for info in infos:
+            print(info['name'])
 
-    # Check for blocklisted processes in cpusets
-    # Skip system cgroups (*.mount, *.scope, *.slice) - these are managed by systemd
+    # Check for blocklisted processes (already collected by get_cpuset_info)
     warnings = []
-    for cs_name in cpusets:
-        # Skip system cgroups - only check user-created cpusets
-        if cs_name.endswith(('.mount', '.scope', '.slice')):
-            continue
-
-        cs_path = os.path.join('/sys/fs/cgroup', cs_name)
-        try:
-            with open(os.path.join(cs_path, 'cgroup.procs'), 'r', encoding='utf-8') as f:
-                pids = [line.strip() for line in f if line.strip()]
-                for pid_str in pids:
-                    try:
-                        pid = int(pid_str)
-                        if cpuset.Cpuset._is_process_blocklisted(pid):
-                            comm = cpuset.Cpuset._get_process_name(pid)
-                            warnings.append(f"⚠️  WARNING: Blocklisted process PID {pid} ({comm}) found in cpuset '{cs_name}'")
-                    except ValueError:
-                        # Invalid PID, skip
-                        pass
-        except (OSError, IOError):
-            # Can't read procs, skip
-            pass
+    for info in infos:
+        if info['blocklisted_pids']:
+            for pid, comm in info['blocklisted_pids']:
+                warnings.append(f"⚠️  WARNING: Blocklisted process PID {pid} ({comm}) found in cpuset '{info['name']}'")
 
     # Display warnings if any
     if warnings:
@@ -1385,12 +1339,13 @@ def cpuset_show(name, show_tasks):
         print("  These critical system processes should not be in custom cpusets!", file=sys.stderr)
 
 
-def cpuset_status(pattern, show_empty, recursive):
+def cpuset_status(pattern, show_empty, show_system, recursive):
     """Handler for 'tuna cpuset status' command.
 
     Args:
         pattern: Glob pattern to filter cpusets (None for all)
         show_empty: If True, show cpusets with no CPUs assigned (default: skip empty)
+        show_system: If True, show systemd-managed cpusets (default: skip system)
         recursive: If True, search nested cpusets
     """
     # Check cgroup v2 support
@@ -1399,8 +1354,9 @@ def cpuset_status(pattern, show_empty, recursive):
         print("Error: cgroup v2 cpusets not supported on this system", file=sys.stderr)
         sys.exit(1)
 
-    # Get all cpusets info (skip_empty is inverse of show_empty)
-    infos = get_all_cpusets_info(pattern=pattern, recursive=recursive, skip_empty=not show_empty)
+    # Get all cpusets info (skip_* params are inverse of show_*)
+    infos = get_all_cpusets_info(pattern=pattern, recursive=recursive,
+                                  skip_empty=not show_empty, skip_system=not show_system)
 
     if not infos:
         if pattern:
@@ -1901,7 +1857,7 @@ def main():
             cpuset_create(args.cpu_list, args.name, args.isolated, args.memory_nodes)
 
         elif args.cpuset_command == 'list':
-            cpuset_list(args.pattern, args.verbose, args.show_empty, args.recursive)
+            cpuset_list(args.pattern, args.verbose, args.show_empty, args.show_system, args.recursive)
 
         elif args.cpuset_command == 'destroy':
             cpuset_destroy(args.name, args.pattern, args.force, args.include_empty, args.recursive)
@@ -1913,7 +1869,7 @@ def main():
             cpuset_show(args.name, args.show_tasks)
 
         elif args.cpuset_command == 'status':
-            cpuset_status(args.pattern, args.show_empty, args.recursive)
+            cpuset_status(args.pattern, args.show_empty, args.show_system, args.recursive)
 
         elif args.cpuset_command == 'modify':
             # Parse CPU lists if provided
-- 
2.55.0