On Mon, Jun 13, 2022 at 10:10:08AM +0200, Oscar Salvador wrote: > On Mon, Jun 13, 2022 at 02:35:08PM +0800, Muchun Song wrote: > > We hold an another reference to hugetlb_optimize_vmemmap_key when > > making vmemmap_optimize_mode on, because we use static_key to tell > > memory_hotplug that memory_hotplug.memmap_on_memory should be > > overridden. However, this rule has gone when we have introduced > > SECTION_CANNOT_OPTIMIZE_VMEMMAP. Therefore, we could simplify > > vmemmap_optimize_mode handling by not holding an another reference > > to hugetlb_optimize_vmemmap_key. > > > > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > > LGTM, and it looks way nicer, so > > Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> > Thanks for taking a look. > One question below though > > > -static enum vmemmap_optimize_mode vmemmap_optimize_mode = > > +static bool vmemmap_optimize_enabled = > > IS_ENABLED(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON); > > So, by default vmemmap_optimize_enabled will be on if we have > CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON, but we can always override that > via cmdline, as below, right? > Totally right. CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON only control if the feature is enabled by default when the users do not specify "it should be off" via cmdline. Thanks.
