Messages in this thread | | | Subject | Re: [PATCH v2 3/7] mm,memory_hotplug: Add kernel boot option to enable memmap_on_memory | From | David Hildenbrand <> | Date | Thu, 25 Feb 2021 19:25:58 +0100 |
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> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 9bcc460e8bfe..95695483a622 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -42,7 +42,31 @@ > #include "internal.h" > #include "shuffle.h" > > -static bool memmap_on_memory_enabled; > +/* > + * memory_hotplug.memmap_on_memory parameter > + */ > +static bool memmap_on_memory_enabled __ro_after_init; > + > +static int memmap_on_memory_show(char *buffer, const struct kernel_param *kp) > +{ > + return sprintf(buffer, "%s\n", > + memmap_on_memory_enabled ? "on" : "off"); > +} > + > +static __meminit int memmap_on_memory_store(const char *val, > + const struct kernel_param *kp) > +{ > + /* > + * Fail silently in case we cannot enable it due to platform constraints. > + * User can always check whether it is enabled or not via /sys/module. > + */ > + if (!IS_ENABLED(CONFIG_ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE)) > + return 0; > + > + return param_set_bool(val, kp); > +} > +module_param_call(memmap_on_memory, memmap_on_memory_store, > + memmap_on_memory_show, &memmap_on_memory_enabled, 0400);
Why are other users not allowed to read?
>
Might want to add a MODULE_PARM_DESC().
As we fail silently already, I'd keep it simple and use a
module_param(memmap_on_memory, bool, 0444);
moving the IS_ENABLED(CONFIG_ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE) into the runtime check.
Apart from that LGTM.
-- Thanks,
David / dhildenb
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