From: Chris Wilson <chris@chris-wilson.co.uk>
To: Intel Graphics Development <intel-gfx@lists.freedesktop.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Subject: Re: [PATCH 15/16] drm/i915: fixup in-line clflushing on bit17 swizzled bos
Date: Mon, 26 Mar 2012 10:18:39 +0100 [thread overview]
Message-ID: <1332753528_97351@CP5-2952> (raw)
In-Reply-To: <1332697663-31256-15-git-send-email-daniel.vetter@ffwll.ch>
On Sun, 25 Mar 2012 19:47:42 +0200, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> The issue is that with inline clflushing the clflushing isn't properly
> swizzled. Fix this by
> - always clflushing entire 128 byte chunks and
> - unconditionally flush before writes when swizzling a given page.
> We could be clever and check whether we pwrite a partial 128 byte
> chunk instead of a partial cacheline, but I've figured that's not
> worth it.
There's some black magic here that I haven't fully grasped. We only ever
swizzle the gpu address (by whole cachelines), so why do we need to
invalidate a pair of cachelines for a single cacheline write?
Also we have a lot of assumptions that the cacheline is 64 bytes. Have
we tested on gen2 where the GPU cacheline is 32 bytes?
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
next prev parent reply other threads:[~2012-03-26 9:18 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-25 17:47 [PATCH 01/16] drm/i915: merge shmem_pwrite slow&fast-path Daniel Vetter
2012-03-25 17:47 ` [PATCH 02/16] drm/i915: merge shmem_pread slow&fast-path Daniel Vetter
2012-03-25 17:47 ` [PATCH 03/16] drm: add helper to clflush a virtual address range Daniel Vetter
2012-03-25 17:47 ` [PATCH 04/16] drm/i915: move clflushing into shmem_pread Daniel Vetter
2012-03-25 17:47 ` [PATCH 05/16] drm/i915: kill ranged cpu read domain support Daniel Vetter
2012-03-25 17:47 ` [PATCH 06/16] drm/i915: don't use gtt_pwrite on LLC cached objects Daniel Vetter
2012-03-25 17:47 ` [PATCH 07/16] drm/i915: don't call shmem_read_mapping unnecessarily Daniel Vetter
2012-03-26 9:10 ` Daniel Vetter
2012-03-25 17:47 ` [PATCH 08/16] drm/i915: drop gtt slowpath Daniel Vetter
2012-03-25 17:47 ` [PATCH 09/16] drm/i915: don't clobber userspace memory before commiting to the pread Daniel Vetter
2012-03-25 17:47 ` [PATCH 10/16] drm/i915: implement inline clflush for pwrite Daniel Vetter
2012-03-25 17:47 ` [PATCH 11/16] drm/i915: fall back to shmem pwrite when the buffer is not accessible Daniel Vetter
2012-03-25 17:47 ` [PATCH 12/16] drm/i915: use uncached writes in pwrite Daniel Vetter
2012-03-25 17:47 ` [PATCH 13/16] drm/i915: extract copy helpers from shmem_pread|pwrite Daniel Vetter
2012-03-26 9:05 ` Chris Wilson
2012-03-25 17:47 ` [PATCH 14/16] mm: extend prefault helpers to fault in more than PAGE_SIZE Daniel Vetter
2012-03-26 9:09 ` Chris Wilson
2012-03-25 17:47 ` [PATCH 15/16] drm/i915: fixup in-line clflushing on bit17 swizzled bos Daniel Vetter
2012-03-26 9:18 ` Chris Wilson [this message]
2012-03-26 9:26 ` Daniel Vetter
2012-03-26 12:50 ` Chris Wilson
2012-03-25 17:47 ` [PATCH 16/16] drm/i915: mark pwrite/pread slowpaths with unlikely Daniel Vetter
2012-03-26 9:09 ` Chris Wilson
2012-03-27 11:42 ` Daniel Vetter
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