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| author | Vlastimil Babka <vbabka@suse.cz> | 2020-08-07 08:18:35 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 20:33:22 +0200 |
| commit | e17f1dfba37b84b574ae91e809ae3804fe5b29b9 (patch) | |
| tree | 7e401a00ebf8b58b60c49a55c41b987a3fc93d3c /Documentation/vm | |
| parent | mm/slab.c: update outdated kmem_list3 in a comment (diff) | |
| download | linux-e17f1dfba37b84b574ae91e809ae3804fe5b29b9.tar.xz linux-e17f1dfba37b84b574ae91e809ae3804fe5b29b9.zip | |
mm, slub: extend slub_debug syntax for multiple blocks
Patch series "slub_debug fixes and improvements".
The slub_debug kernel boot parameter can either apply a single set of
options to all caches or a list of caches. There is a use case where
debugging is applied for all caches and then disabled at runtime for
specific caches, for performance and memory consumption reasons [1]. As
runtime changes are dangerous, extend the boot parameter syntax so that
multiple blocks of either global or slab-specific options can be
specified, with blocks delimited by ';'. This will also support the use
case of [1] without runtime changes.
For details see the updated Documentation/vm/slub.rst
[1] https://lore.kernel.org/r/1383cd32-1ddc-4dac-b5f8-9c42282fa81c@codeaurora.org
[weiyongjun1@huawei.com: make parse_slub_debug_flags() static]
Link: http://lkml.kernel.org/r/20200702150522.4940-1-weiyongjun1@huawei.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Jann Horn <jannh@google.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200610163135.17364-2-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/vm')
| -rw-r--r-- | Documentation/vm/slub.rst | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/vm/slub.rst b/Documentation/vm/slub.rst index 4eee598555c9..cfccb258cf42 100644 --- a/Documentation/vm/slub.rst +++ b/Documentation/vm/slub.rst @@ -41,6 +41,11 @@ slub_debug=<Debug-Options>,<slab name1>,<slab name2>,... Enable options only for select slabs (no spaces after a comma) +Multiple blocks of options for all slabs or selected slabs can be given, with +blocks of options delimited by ';'. The last of "all slabs" blocks is applied +to all slabs except those that match one of the "select slabs" block. Options +of the first "select slabs" blocks that matches the slab's name are applied. + Possible debug options are:: F Sanity checks on (enables SLAB_DEBUG_CONSISTENCY_CHECKS @@ -83,6 +88,19 @@ switch off debugging for such caches by default, use:: slub_debug=O +You can apply different options to different list of slab names, using blocks +of options. This will enable red zoning for dentry and user tracking for +kmalloc. All other slabs will not get any debugging enabled:: + + slub_debug=Z,dentry;U,kmalloc-* + +You can also enable options (e.g. sanity checks and poisoning) for all caches +except some that are deemed too performance critical and don't need to be +debugged by specifying global debug options followed by a list of slab names +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:: |