[PATCH 2/6] drm/radeon: track memory statistics about VRAM and GTT usage and buffer moves

[Christian König]

Am 26.02.2014 18:56, schrieb Marek Olšák:
> On Mon, Feb 24, 2014 at 5:20 PM, Christian König
> <deathsimple at vodafone.de> wrote:
>> Am 24.02.2014 16:20, schrieb Marek Olšák:
>>
>>> From: Marek Olšák <marek.olsak at amd.com>
>>>
>>> The statistics are:
>>> - VRAM usage in bytes
>>> - GTT usage in bytes
>>> - number of bytes moved by TTM
>>>
>>> The last one is actually a counter, so you need to sample it before and
>>> after
>>> command submission and take the difference.
>>>
>>> This is useful for finding performance bottlenecks. Userspace queries are
>>> also added.
>>>
>>> Signed-off-by: Marek Olšák <marek.olsak at amd.com>
>>> ---
>>>    drivers/gpu/drm/radeon/radeon.h        |  5 +++++
>>>    drivers/gpu/drm/radeon/radeon_device.c |  1 +
>>>    drivers/gpu/drm/radeon/radeon_kms.c    | 15 ++++++++++++++
>>>    drivers/gpu/drm/radeon/radeon_object.c | 38
>>> +++++++++++++++++++++++++++++++++-
>>>    drivers/gpu/drm/radeon/radeon_object.h |  2 +-
>>>    drivers/gpu/drm/radeon/radeon_ttm.c    | 10 ++++++++-
>>>    include/uapi/drm/radeon_drm.h          |  3 +++
>>>    7 files changed, 71 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/radeon/radeon.h
>>> b/drivers/gpu/drm/radeon/radeon.h
>>> index 3f10782..d37a57a 100644
>>> --- a/drivers/gpu/drm/radeon/radeon.h
>>> +++ b/drivers/gpu/drm/radeon/radeon.h
>>> @@ -2307,6 +2307,11 @@ struct radeon_device {
>>>          /* virtual memory */
>>>          struct radeon_vm_manager        vm_manager;
>>>          struct mutex                    gpu_clock_mutex;
>>> +       /* memory stats */
>>> +       struct mutex                    memory_stats_mutex;
>>> +       uint64_t                        vram_usage;
>>> +       uint64_t                        gtt_usage;
>>> +       uint64_t                        num_bytes_moved;
>>
>> As far as I can see you could make those tree values atomic64_t instead and
>> avoid the mutex.
> I'm afraid I cannot use atomic64_t. It doesn't work on x86 32-bit.
> This seems to be a no-op:
>
> u64 size = (u64)bo->num_pages << PAGE_SHIFT;
> atomic64_add(size, &rdev->num_bytes_moved);

Are you sure about this? Haven't tested x86 32-bit in a long time, but 
we use atomic64 all around the place and they usually work perfectly.

Christian.

> Marek