The alloc_calls file is read-only and lists the kernel code
locations from which allocations for this cache were performed.
The alloc_calls file only contains information if debugging is
- enabled for that cache (see Documentation/mm/slub.rst).
+ enabled for that cache (see
+ Documentation/admin-guide/mm/slab.rst).
What: /sys/kernel/slab/<cache>/alloc_fastpath
Date: February 2008
Description:
The free_calls file is read-only and lists the locations of
object frees if slab debugging is enabled (see
- Documentation/mm/slub.rst).
+ Documentation/admin-guide/mm/slab.rst).
What: /sys/kernel/slab/<cache>/free_fastpath
Date: February 2008
slab_debug can create guard zones around objects and
may poison objects when not in use. Also tracks the
last alloc / free. For more information see
- Documentation/mm/slub.rst.
+ Documentation/admin-guide/mm/slab.rst.
(slub_debug legacy name also accepted for now)
slab_max_order= [MM]
Determines the maximum allowed order for slabs.
A high setting may cause OOMs due to memory
fragmentation. For more information see
- Documentation/mm/slub.rst.
+ Documentation/admin-guide/mm/slab.rst.
(slub_max_order legacy name also accepted for now)
slab_merge [MM]
the number of objects indicated. The higher the number
of objects the smaller the overhead of tracking slabs
and the less frequently locks need to be acquired.
- For more information see Documentation/mm/slub.rst.
+ For more information see
+ Documentation/admin-guide/mm/slab.rst.
(slub_min_objects legacy name also accepted for now)
slab_min_order= [MM]
Determines the minimum page order for slabs. Must be
lower or equal to slab_max_order. For more information see
- Documentation/mm/slub.rst.
+ Documentation/admin-guide/mm/slab.rst.
(slub_min_order legacy name also accepted for now)
slab_nomerge [MM]
cache (risks via metadata attacks are mostly
unchanged). Debug options disable merging on their
own.
- For more information see Documentation/mm/slub.rst.
+ For more information see
+ Documentation/admin-guide/mm/slab.rst.
(slub_nomerge legacy name also accepted for now)
slab_strict_numa [MM]
-==========================
-Short users guide for SLUB
-==========================
-
-The basic philosophy of SLUB is very different from SLAB. SLAB
-requires rebuilding the kernel to activate debug options for all
-slab caches. SLUB always includes full debugging but it is off by default.
-SLUB can enable debugging only for selected slabs in order to avoid
-an impact on overall system performance which may make a bug more
-difficult to find.
+========================================
+Short users guide for the slab allocator
+========================================
+
+The slab allocator includes full debugging support (when built with
+CONFIG_SLUB_DEBUG=y) but it is off by default (unless built with
+CONFIG_SLUB_DEBUG_ON=y). You can enable debugging only for selected
+slabs in order to avoid an impact on overall system performance which
+may make a bug more difficult to find.
In order to switch debugging on one can add an option ``slab_debug``
to the kernel command line. That will enable full debugging for