On 7/13/21 1:45 PM, vjitta@xxxxxxxxxxxxxx wrote:
> From: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx>
>
> Consider the scenario where CONFIG_SLUB_DEBUG_ON is set
> and we would want to disable slub_debug for few slabs.
> Using boot parameter with slub_debug=-,slab_name syntax
> doesn't work as expected i.e; only disabling debugging for
> the specified list of slabs, instead it disables debugging
> for all slabs. Fix this.
>
> Signed-off-by: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx>
Would the following work too, and perhaps be easier to follow?
----8<----
diff --git a/mm/slub.c b/mm/slub.c
index 090fa14628f9..024f49706386 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1400,12 +1400,13 @@ parse_slub_debug_flags(char *str, slab_flags_t *flags, char **slabs, bool init)
static int __init setup_slub_debug(char *str)
{
slab_flags_t flags;
+ slab_flags_t global_flags;
char *saved_str;
char *slab_list;
bool global_slub_debug_changed = false;
bool slab_list_specified = false;
- slub_debug = DEBUG_DEFAULT_FLAGS;
+ global_flags = DEBUG_DEFAULT_FLAGS;
if (*str++ != '=' || !*str)
/*
* No options specified. Switch on full debugging.
@@ -1417,7 +1418,7 @@ static int __init setup_slub_debug(char *str)
str = parse_slub_debug_flags(str, &flags, &slab_list, true);
if (!slab_list) {
- slub_debug = flags;
+ global_flags = flags;
global_slub_debug_changed = true;
} else {
slab_list_specified = true;
@@ -1426,16 +1427,18 @@ static int __init setup_slub_debug(char *str)
/*
* For backwards compatibility, a single list of flags with list of
- * slabs means debugging is only enabled for those slabs, so the global
- * slub_debug should be 0. We can extended that to multiple lists as
+ * slabs means debugging is only changed for those slabs, so the global
+ * slub_debug should be unchanged (0 or DEBUG_DEFAULT_FLAGS, depending
+ * on CONFIG_SLUB_DEBUG_ON). We can extended that to multiple lists as
* long as there is no option specifying flags without a slab list.
*/
if (slab_list_specified) {
if (!global_slub_debug_changed)
- slub_debug = 0;
+ global_flags = slub_debug;
slub_debug_string = saved_str;
}
out:
+ slub_debug = global_flags;
if (slub_debug != 0 || slub_debug_string)
static_branch_enable(&slub_debug_enabled);
else
--
2.32.0
