Re: [PATCH 2/8] xen/balloon: Move common memory reservation routines to a module

[Oleksandr Andrushchenko]

On 05/31/2018 10:51 AM, Oleksandr Andrushchenko wrote:
> On 05/30/2018 10:24 PM, Boris Ostrovsky wrote:
> > On 05/30/2018 01:46 PM, Oleksandr Andrushchenko wrote:
> > > On 05/30/2018 06:54 PM, Boris Ostrovsky wrote:
> > > > BTW, I also think you can further simplify
> > > > xenmem_reservation_va_mapping_* routines by bailing out right away if
> > > > xen_feature(XENFEAT_auto_translated_physmap). In fact, you might even
> > > > make them inlines, along the lines of
> > > >
> > > > inline void xenmem_reservation_va_mapping_reset(unsigned long count,
> > > > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct page **pages)
> > > > {
> > > > #ifdef CONFIG_XEN_HAVE_PVMMU
> > > > ÂÂÂÂÂif (!xen_feature(XENFEAT_auto_translated_physmap))
> > > > ÂÂÂÂÂÂÂÂ __xenmem_reservation_va_mapping_reset(...)
> > > > #endif
> > > > }
> > > How about:
> > >
> > > #ifdef CONFIG_XEN_HAVE_PVMMU
> > > static inline __xenmem_reservation_va_mapping_reset(struct page *page)
> > > {
> > > [...]
> > > }
> > > #endif
> > >
> > > and
> > >
> > > void xenmem_reservation_va_mapping_reset(unsigned long count,
> > > ÂÂÂÂ ÂÂÂ ÂÂÂ ÂÂÂ ÂÂÂ Âstruct page **pages)
> > > {
> > > #ifdef CONFIG_XEN_HAVE_PVMMU
> > > ÂÂÂÂ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
> > > ÂÂÂÂ ÂÂÂ int i;
> > >
> > > ÂÂÂÂ ÂÂÂ for (i = 0; i < count; i++)
> > > ÂÂÂÂ ÂÂÂ ÂÂÂ __xenmem_reservation_va_mapping_reset(pages[i]);
> > > ÂÂÂÂ }
> > > #endif
> > > }
> > >
> > > This way I can use __xenmem_reservation_va_mapping_reset(page);
> > > instead of xenmem_reservation_va_mapping_reset(1, &page);
> >
> > Sure, this also works.
> Could you please take look at the patch attached if this is what we want?
Please ignore it, it is ugly ;)
I have implemented this as you suggested:

static inline void
xenmem_reservation_va_mapping_update(unsigned long count,
ÂÂÂ ÂÂÂ ÂÂÂ ÂÂÂ ÂÂÂÂ struct page **pages,
ÂÂÂ ÂÂÂ ÂÂÂ ÂÂÂ ÂÂÂÂ xen_pfn_t *frames)
{
#ifdef CONFIG_XEN_HAVE_PVMMU
ÂÂÂ if (!xen_feature(XENFEAT_auto_translated_physmap))
ÂÂÂ ÂÂÂ __xenmem_reservation_va_mapping_update(count, pages, frames);
#endif
}

> > -boris
> Thank you,
> Oleksandr