[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <6b9c8566-926d-40ff-7907-228d317fab3d@linux.intel.com>
Date: Thu, 21 Sep 2023 11:14:27 +0100
From: Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>
To: Adrián Larumbe <adrian.larumbe@...labora.com>,
maarten.lankhorst@...ux.intel.com, mripard@...nel.org,
tzimmermann@...e.de, airlied@...il.com, daniel@...ll.ch,
robdclark@...il.com, quic_abhinavk@...cinc.com,
dmitry.baryshkov@...aro.org, sean@...rly.run,
marijn.suijten@...ainline.org, robh@...nel.org,
steven.price@....com
Cc: linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
dri-devel@...ts.freedesktop.org, healych@...zon.com,
Boris Brezillon <boris.brezillon@...labora.com>,
kernel@...labora.com, freedreno@...ts.freedesktop.org
Subject: Re: [PATCH v6 6/6] drm/drm-file: Show finer-grained BO sizes in
drm_show_memory_stats
On 20/09/2023 16:32, Tvrtko Ursulin wrote:
>
> On 20/09/2023 00:34, Adrián Larumbe wrote:
>> The current implementation will try to pick the highest available size
>> display unit as soon as the BO size exceeds that of the previous
>> multiplier. That can lead to loss of precision in contexts of low memory
>> usage.
>>
>> The new selection criteria try to preserve precision, whilst also
>> increasing the display unit selection threshold to render more accurate
>> values.
>>
>> Signed-off-by: Adrián Larumbe <adrian.larumbe@...labora.com>
>> Reviewed-by: Boris Brezillon <boris.brezillon@...labora.com>
>> Reviewed-by: Steven Price <steven.price@....com>
>> ---
>> drivers/gpu/drm/drm_file.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
>> index 762965e3d503..34cfa128ffe5 100644
>> --- a/drivers/gpu/drm/drm_file.c
>> +++ b/drivers/gpu/drm/drm_file.c
>> @@ -872,6 +872,8 @@ void drm_send_event(struct drm_device *dev, struct
>> drm_pending_event *e)
>> }
>> EXPORT_SYMBOL(drm_send_event);
>> +#define UPPER_UNIT_THRESHOLD 100
>> +
>> static void print_size(struct drm_printer *p, const char *stat,
>> const char *region, u64 sz)
>> {
>> @@ -879,7 +881,8 @@ static void print_size(struct drm_printer *p,
>> const char *stat,
>> unsigned u;
>> for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
>> - if (sz < SZ_1K)
>> + if ((sz & (SZ_1K - 1)) &&
>
> IS_ALIGNED worth it at all?
>
>> + sz < UPPER_UNIT_THRESHOLD * SZ_1K)
>> break;
>
> Excuse me for a late comment (I was away). I did not get what what is
> special about a ~10% threshold? Sounds to me just going with the lower
> unit, when size is not aligned to the higher one, would be better than
> sometimes precision-sometimes-not.
FWIW both current and the threshold option make testing the feature very
annoying.
So I'd really propose we simply use smaller unit when unaligned.
Regards,
Tvrtko
Powered by blists - more mailing lists