crash-python · AlexanderKamensky · Nov 2, 2020 · Nov 3, 2020 · Nov 4, 2020
diff --git a/crash/commands/kmem.py b/crash/commands/kmem.py
@@ -25,12 +25,21 @@

 from crash.commands import Command, ArgumentParser
 from crash.commands import CommandError, CommandLineError
-from crash.types.slab import kmem_cache_get_all, kmem_cache_from_name
-from crash.types.slab import slab_from_obj_addr, KmemCacheNotFound
 from crash.types.node import for_each_zone, for_each_populated_zone
 from crash.types.vmstat import VmStat
 from crash.util import get_symbol_value
 from crash.exceptions import MissingSymbolError
+from crash.cache.syscache import config
+
+if config["SLUB"]:
+    slub_kernel = True
+else:
+    slub_kernel = False
+    try:
+        from crash.types.slab import kmem_cache_get_all, kmem_cache_from_name
+        from crash.types.slab import slab_from_obj_addr, KmemCacheNotFound
+    except TypeError:
+        slub_kernel = True

 class KmemCommand(Command):
    """ kernel memory inspection"""
@@ -56,6 +65,11 @@ def execute(self, args: argparse.Namespace) -> None:
            self.print_vmstats()
            return

+        if slub_kernel:
+            # not supported for now
+            print("-s and address options not supported on non-SLAB systems")
+            return
+
        if args.slabname:
            if args.slabname is True:
                print("Checking all kmem caches...")

diff --git a/crash/types/page.py b/crash/types/page.py
@@ -141,7 +141,7 @@ def setup_nodes_width(cls, symbol: Union[gdb.Symbol, gdb.MinSymbol]) -> None:
        # TODO: handle kernels with no space for nodes in page flags
        try:
            cls.NODES_WIDTH = int(config['NODES_SHIFT'])
-        except (KeyError, DelayedAttributeError):
+        except (KeyError, TypeError, DelayedAttributeError):
            # XXX
            print("Unable to determine NODES_SHIFT from config, trying 8")
            cls.NODES_WIDTH = 8

diff --git a/crash/types/task.py b/crash/types/task.py
@@ -588,6 +588,9 @@ def _last_run__timestamp(self) -> int:
    def _last_run__last_arrival(self) -> int:
        return int(self.task_struct['sched_info']['last_arrival'])

+    def _last_run__return_zero(self) -> int:
+        return 0
+
    @classmethod
    def _pick_last_run(cls) -> None:
        fields = types.task_struct_type.keys()
@@ -601,7 +604,8 @@ def _pick_last_run(cls) -> None:
        elif 'timestamp' in fields:
            cls._get_last_run = cls._last_run__timestamp
        else:
-            raise RuntimeError("No method to retrieve last run from task found.")
+            cls._get_last_run = cls._last_run__return_zero
+            print("No method to retrieve last run from task found. Consider enabling CONFIG_TASKSTATS and CONFIG_TASK_DELAY_ACCT to activate CONFIG_SCHED_INFO kernel config")

    def last_run(self) -> int:
        """