On Thu, May 12, 2022 at 09:41:22AM +0200, David Hildenbrand wrote:
> On 09.05.22 08:27, Muchun Song wrote:
> > Use kstrtobool rather than open coding "on" and "off" parsing in
> > mm/hugetlb_vmemmap.c, which is more powerful to handle all kinds
> > of parameters like 'Yy1Nn0' or [oO][NnFf] for "on" and "off".
> >
> > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> > Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> > ---
> > Documentation/admin-guide/kernel-parameters.txt | 6 +++---
> > mm/hugetlb_vmemmap.c | 10 +++++-----
> > 2 files changed, 8 insertions(+), 8 deletions(-)
> >
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> > index 308da668bbb1..43b8385073ad 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -1703,10 +1703,10 @@
> > enabled.
> > Allows heavy hugetlb users to free up some more
> > memory (7 * PAGE_SIZE for each 2MB hugetlb page).
> > - Format: { on | off (default) }
> > + Format: { [oO][Nn]/Y/y/1 | [oO][Ff]/N/n/0 (default) }
>
> Really? Can we make the syntax even harder to parse for human beings?! :)
>
> Not to mention that it's partially wrong? What about "oFf" ? That would
> have to be [oO][Ff][Ff]
>
> Honestly, "on | off" is good enough. That "oN" and friends work is just
> a "nice to have" IMHO. No need to over-complicate this description.
Got it. How about also telling users "on/1 | off/0"? Because 0 and
1 are also widely used to disable/enable a knob.
> >
> > - on: enable the feature
> > - off: disable the feature
> > + [oO][Nn]/Y/y/1: enable the feature
> > + [oO][Ff]/N/n/0: disable the feature
> >
> > Built with CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON=y,
> > the default is on.
> > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
> > index 6254bb2d4ae5..cc4ec752ec16 100644
> > --- a/mm/hugetlb_vmemmap.c
> > +++ b/mm/hugetlb_vmemmap.c
> > @@ -28,15 +28,15 @@ EXPORT_SYMBOL(hugetlb_optimize_vmemmap_key);
> >
> > static int __init hugetlb_vmemmap_early_param(char *buf)
> > {
> > - if (!buf)
> > + bool enable;
> > +
> > + if (kstrtobool(buf, &enable))
> > return -EINVAL;
> >
> > - if (!strcmp(buf, "on"))
> > + if (enable)
> > static_branch_enable(&hugetlb_optimize_vmemmap_key);
> > - else if (!strcmp(buf, "off"))
> > - static_branch_disable(&hugetlb_optimize_vmemmap_key);
> > else
> > - return -EINVAL;
> > + static_branch_disable(&hugetlb_optimize_vmemmap_key);
> >
> > return 0;
> > }
>
>
> Apart from that
>
> Acked-by: David Hildenbrand <david@xxxxxxxxxx>
>
Thanks.
> --
> Thanks,
>
> David / dhildenb
>
>
