[Intel-gfx] [PATCH v6 00/32] PPGTT dynamic page allocations and 48b addressing

[Daniel Vetter]

On Wed, Feb 25, 2015 at 12:29:50PM +0000, Michel Thierry wrote:
> On 2/25/2015 10:55 AM, Mika Kuoppala wrote:
> >Daniel Vetter <daniel at ffwll.ch> writes:
> >
> >>On Tue, Feb 24, 2015 at 04:22:33PM +0000, Michel Thierry wrote:
> >>>This patchset addresses comments from v5 by Mika, specially some rename changes
> >>>touched several patches.
> >>>
> >>>For GEN8, it has also been extended to work in logical ring submission (lrc)
> >>>mode, as it will be the preferred mode of operation.
> >>>I also tried to update the lrc code at the same time the ppgtt refactoring
> >>>occurred, leaving only one patch that is exclusively for lrc.
> >>>
> >>>I'm also now including the required patches for PPGTT with 48b addressing.
> >>>In order expand the GPU address space, a 4th level translation is added, the
> >>>Page Map Level 4 (PML4). This PML4 has 256 PML4 Entries (PML4E), PML4[0-255],
> >>>each pointing to a PDP.
> >>>
> >>>For now, this feature will only be available in BDW and GEN9, in LRC submission
> >>>mode (execlists) and when i915.enable_ppgtt=3 is set.
> >>>Also note that this expanded address space is only available for full PPGTT,
> >>>aliasing PPGTT remains 32b.
> >>>
> >>>This list can be seen in 3 parts:
> >>>[01-10] Add page table allocation for GEN6/GEN7
> >>>[11-20] Enable dynamic allocation in GEN8,for both legacy and
> >>>execlist submission modes.
> >>>[21-32] PML4 support in BDW and GEN9+.
> >>>
> >>>Ben Widawsky (26):
> >>>   drm/i915: page table abstractions
> >>>   drm/i915: Complete page table structures
> >>>   drm/i915: Create page table allocators
> >>>   drm/i915: Track GEN6 page table usage
> >>>   drm/i915: Extract context switch skip and pd load logic
> >>>   drm/i915: Track page table reload need
> >>>   drm/i915: Initialize all contexts
> >>>   drm/i915: Finish gen6/7 dynamic page table allocation
> >>>   drm/i915/bdw: Use dynamic allocation idioms on free
> >>>   drm/i915/bdw: page directories rework allocation
> >>>   drm/i915/bdw: pagetable allocation rework
> >>>   drm/i915/bdw: Update pdp switch and point unused PDPs to scratch page
> >>>   drm/i915: num_pd_pages/num_pd_entries isn't useful
> >>>   drm/i915: Extract PPGTT param from page_directory alloc
> >>>   drm/i915/bdw: Split out mappings
> >>>   drm/i915/bdw: begin bitmap tracking
> >>>   drm/i915/bdw: Dynamic page table allocations
> >>>   drm/i915/bdw: Make pdp allocation more dynamic
> >>>   drm/i915/bdw: Abstract PDP usage
> >>>   drm/i915/bdw: Add dynamic page trace events
> >>>   drm/i915/bdw: Add ppgtt info for dynamic pages
> >>>   drm/i915/bdw: implement alloc/free for 4lvl
> >>>   drm/i915/bdw: Add 4 level switching infrastructure
> >>>   drm/i915/bdw: Generalize PTE writing for GEN8 PPGTT
> >>>   drm/i915: Plumb sg_iter through va allocation ->maps
> >>>   drm/i915: Expand error state's address width to 64b
> >>>
> >>>Michel Thierry (6):
> >>>   drm/i915: Plumb drm_device through page tables operations
> >>>   drm/i915: Add dynamic page trace events
> >>>   drm/i915/bdw: Support dynamic pdp updates in lrc mode
> >>>   drm/i915/bdw: Support 64 bit PPGTT in lrc mode
> >>>   drm/i915/bdw: Add 4 level support in insert_entries and clear_range
> >>>   drm/i915/bdw: Flip the 48b switch
> >>When just a few patches changed (which I suspect is the case here) please
> >>don't resend the entire series, but only resend the individual patches
> >>in-reply-to their earlier versions.
> >>
> >>Resending the entire series too often tends to split up the discussions
> >>between multiple threads, so should be used cautiously. My approach is
> >>that I don't resend the entire series except when all the patches have
> >>changed. And I only resend when the review round has reached a conclusion.
> >>While the review is ongoing doing incremental updates of the series is imo
> >>much better.
> >>
> >>But when resending the entire series, please start a new thread. Otherwise
> >>it again starts to become unclear which versions of which patches go
> >>together.
> >>
> >>And a quick aside if you fear that a patch causes subsequent patches to no
> >>longer apply without a rebase: I can deal with a lot of small conflicts
> >>quickly when merging. And if that doesn't cut it I'll just ask for a
> >>resend when needed.
> >>
> >I have been asking alot of stuff that triggers a rebasing. I suggest we
> >should keep the 48b items in a separate series until we have most of the
> >dynamic page table series sorted out.
> >
> >- Mika
> Ok, I'll keep dynamic page allocation and 48b separated.

Yeah I didn't realize that these two have been merged. Another bkm is to
keep patch-series for detailed code-review at 10-20 patches tops. More
thens to just result in a lot more churn for every minimal rebase on the
patch authors side. And also tends to burn out reviewers ime.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch