[PATCH 1/5] drm/ttm: Merge hugepage attr changes in ttm_dma_page_put.

[Bas Nieuwenhuizen]

On Thu, Jul 26, 2018 at 11:39 AM Huang Rui <ray.huang at amd.com> wrote:
>
> On Thu, Jul 26, 2018 at 05:28:53PM +0800, Christian König wrote:
> > Am 26.07.2018 um 11:14 schrieb Huang Rui:
> > > From: Bas Nieuwenhuizen <basni at chromium.org>
> > >
> > > Every set_pages_array_wb call resulted in cross-core
> > > interrupts and TLB flushes. Merge more of them for
> > > less overhead.
> > >
> > > This reduces the time needed to free a 1.6 GiB GTT WC
> > > buffer as part of Vulkan CTS from  ~2 sec to < 0.25 sec.
> > > (Allocation still takes more than 2 sec though)
> > >
> > > Signed-off-by: Bas Nieuwenhuizen <basni at chromium.org>
> > > Signed-off-by: Huang Rui <ray.huang at amd.com>
> > > ---
> > >   drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 30 +++++++++++++++++++++++-------
> > >   1 file changed, 23 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> > > index 3f14c1c..27fb543 100644
> > > --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> > > +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> > > @@ -301,6 +301,25 @@ static int set_pages_array_uc(struct page **pages, int addrinarray)
> > >   #endif
> > >     return 0;
> > >   }
> > > +
> > > +static int ttm_set_page_range_wb(struct page *p, unsigned long numpages)
> > > +{
> > > +#if IS_ENABLED(CONFIG_AGP)
> > > +        unsigned long i;
> > > +
> > > +        for (i = 0; i < numpages; i++)
> > > +                unmap_page_from_agp(p + i);
> > > +#endif
> > > +   return 0;
> > > +}
> > > +
> > > +#else /* for !CONFIG_X86 */
> > > +
> > > +static int ttm_set_page_range_wb(struct page *p, unsigned long numpages)
> > > +{
> > > +   return set_memory_wb((unsigned long)page_address(p), numpages);
> > > +}
> >
> > Please use set_pages_wb() here instead of set_memory_wb(), this way it
> > should also work on 32bit systems.
> >
>
> Actually, I fix it in patch 5 ("drm/ttm: use set_pages_wb instead of
> set_memory_wb"). So should I sequeeze it int this patch? There is SMTP
> network issue in SRDC, other patches are timeout...

I'd say fix it up in this patch (You can avoid introducing
ttm_set_page_range_wb that way as it is equal to set_pages_wb) and
then put this patch at the end of your series. Since ttm_page_alloc.c
already has a set_pages_wb fallback implementation that means we do
not introduce code just to deduplicate it later in the series anymore.

>
> [Net::SMTP] Timeout at /usr/lib/git-core/git-send-email line 1393.
>
> Let me resend them into dri-devel as well.
>
> Thanks,
> Ray