diff options
Diffstat (limited to 'Documentation/vm')
| -rw-r--r-- | Documentation/vm/slub.rst | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/Documentation/vm/slub.rst b/Documentation/vm/slub.rst index cfccb258cf42..36241dfba024 100644 --- a/Documentation/vm/slub.rst +++ b/Documentation/vm/slub.rst @@ -101,20 +101,26 @@ with "-" as options:: slub_debug=FZ;-,zs_handle,zspage -In case you forgot to enable debugging on the kernel command line: It is -possible to enable debugging manually when the kernel is up. Look at the -contents of:: +The state of each debug option for a slab can be found in the respective files +under:: /sys/kernel/slab/<slab name>/ -Look at the writable files. Writing 1 to them will enable the -corresponding debug option. All options can be set on a slab that does -not contain objects. If the slab already contains objects then sanity checks -and tracing may only be enabled. The other options may cause the realignment -of objects. - -Careful with tracing: It may spew out lots of information and never stop if -used on the wrong slab. +If the file contains 1, the option is enabled, 0 means disabled. The debug +options from the ``slub_debug`` parameter translate to the following files:: + + F sanity_checks + Z red_zone + P poison + U store_user + T trace + A failslab + +The sanity_checks, trace and failslab files are writable, so writing 1 or 0 +will enable or disable the option at runtime. The writes to trace and failslab +may return -EINVAL if the cache is subject to slab merging. Careful with +tracing: It may spew out lots of information and never stop if used on the +wrong slab. Slab merging ============ |