Re: [RFC PATCH 1/1] drm/mm: add ig_frag selftest

[Nirmoy <nirmodas@amd.com>]

On 5/29/20 5:52 PM, Chris Wilson wrote:
> Quoting Nirmoy (2020-05-29 16:40:53)
>> This works correctly most of the times but sometimes


I have to take my word back. In another machine,  20k insertions in

best mode takes 6-9 times more than 10k insertions, all most all the time.

evict, bottom-up and top-down modes remains in 2-5 times range.


If I reduce the insertions to 1k and 2k then scaling factor for best 
mode stays  below 4 most of the time.

evict, bottom-up and top-down modes remains in 2-3 times range.


I wonder if it makes sense to test with only 1k and 2k insertions and 
tolerate more than error if the mode == best.

Regards,

Nirmoy

>>
>> 20k insertions can take more than 8 times of 10k insertion time.
> The pressure is on to improve then :)
>
>> Regards,
>>
>> Nirmoy
>>
>> On 5/29/20 6:33 PM, Nirmoy Das wrote:
>>> This patch introduces fragmentation in the address range
>>> and measures time taken by 10k and 20k insertions. ig_frag()
>>> will fail if time taken by 20k insertions takes more than 4 times
>>> of 10k insertions as we know that insertions scale quadratically.
>>> Also tolerate 10% error because of kernel scheduler's jitters.
>>>
>>> Output:
>>> <snip>
>>> [ 8092.653518] drm_mm: Testing DRM range manger (struct drm_mm), with random_seed=0x9bfb4117 max_iterations=8192 max_prime=128
>>> [ 8092.653520] drm_mm: igt_sanitycheck - ok!
>>> [ 8092.653525] igt_debug 0x0000000000000000-0x0000000000000200: 512: free
>>> [ 8092.653526] igt_debug 0x0000000000000200-0x0000000000000600: 1024: used
>>> [ 8092.653527] igt_debug 0x0000000000000600-0x0000000000000a00: 1024: free
>>> [ 8092.653528] igt_debug 0x0000000000000a00-0x0000000000000e00: 1024: used
>>> [ 8092.653529] igt_debug 0x0000000000000e00-0x0000000000001000: 512: free
>>> [ 8092.653529] igt_debug total: 4096, used 2048 free 2048
>>> [ 8112.569813] drm_mm: best fragmented insert of 10000 and 20000 insertions took 504 and 1996 msecs
>>> [ 8112.723254] drm_mm: bottom-up fragmented insert of 10000 and 20000 insertions took 44 and 108 msecs
>>> [ 8112.813212] drm_mm: top-down fragmented insert of 10000 and 20000 insertions took 40 and 44 msecs
>>> [ 8112.847733] drm_mm: evict fragmented insert of 10000 and 20000 insertions took 8 and 20 msecs
>>> <snip>
>>>
>>> Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
>>> ---
>>>    drivers/gpu/drm/selftests/drm_mm_selftests.h |  1 +
>>>    drivers/gpu/drm/selftests/test-drm_mm.c      | 73 ++++++++++++++++++++
>>>    2 files changed, 74 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/selftests/drm_mm_selftests.h b/drivers/gpu/drm/selftests/drm_mm_selftests.h
>>> index 6b943ea1c57d..8c87c964176b 100644
>>> --- a/drivers/gpu/drm/selftests/drm_mm_selftests.h
>>> +++ b/drivers/gpu/drm/selftests/drm_mm_selftests.h
>>> @@ -14,6 +14,7 @@ selftest(insert, igt_insert)
>>>    selftest(replace, igt_replace)
>>>    selftest(insert_range, igt_insert_range)
>>>    selftest(align, igt_align)
>>> +selftest(frag, igt_frag)
>>>    selftest(align32, igt_align32)
>>>    selftest(align64, igt_align64)
>>>    selftest(evict, igt_evict)
>>> diff --git a/drivers/gpu/drm/selftests/test-drm_mm.c b/drivers/gpu/drm/selftests/test-drm_mm.c
>>> index 9aabe82dcd3a..05d8f3659b4d 100644
>>> --- a/drivers/gpu/drm/selftests/test-drm_mm.c
>>> +++ b/drivers/gpu/drm/selftests/test-drm_mm.c
>>> @@ -1033,6 +1033,79 @@ static int igt_insert_range(void *ignored)
>>>        return 0;
>>>    }
>>>    
>>> +static int get_insert_time(unsigned int num_insert,
>>> +                        const struct insert_mode *mode)
>>> +{
>>> +     struct drm_mm mm;
>>> +     struct drm_mm_node *nodes, *node, *next;
>>> +     unsigned int size = 4096, align = 8192;
>>> +     unsigned long start;
>>> +     unsigned int i;
>>> +     int ret = -EINVAL;
>>> +
>>> +     drm_mm_init(&mm, 1, U64_MAX - 2);
>>> +     nodes = vzalloc(array_size(num_insert, sizeof(*nodes)));
>>> +     if (!nodes)
>>> +             goto err;
>>> +
>>> +     start = jiffies;
> Use ktime_t start = ktime_now();
>
>>> +     for (i = 0; i < num_insert; i++) {
>>> +             if (!expect_insert(&mm, &nodes[i], size, align, i, mode)) {
>>> +                     pr_err("%s insert failed\n", mode->name);
>>> +                     goto out;
>>> +             }
>>> +     }
>>> +
>>> +     ret = jiffies_to_msecs(jiffies - start);
> ret = ktime_sub(ktime_now(), start);
>
> The downside to using ktime is remembering it is s64 and so requires care
> and attention in doing math.
>
>>> +out:
>>> +     drm_mm_for_each_node_safe(node, next, &mm)
>>> +             drm_mm_remove_node(node);
>>> +     drm_mm_takedown(&mm);
>>> +     vfree(nodes);
>>> +err:
>>> +     return ret;
>>> +
>>> +}
>>> +
>>> +static int igt_frag(void *ignored)
>>> +{
>>> +     const struct insert_mode *mode;
>>> +     unsigned int insert_time1, insert_time2;
>>> +     unsigned int insert_size = 10000;
>>> +     unsigned int scale_factor = 4;
>>> +     /* tolerate 10% excess insertion duration */
>>> +     unsigned int error_factor = 110;
>>> +     int ret = -EINVAL;
>>> +
>>> +     for (mode = insert_modes; mode->name; mode++) {
>>> +             unsigned int expected_time;
>>> +
>>> +             insert_time1 = get_insert_time(insert_size, mode);
>>> +             if (insert_time1 < 0)
>>> +                     goto err;
> Ah, can you propagate the actual error. I see you are returning EINVAL
> for ENOMEM errors. Just wait until it hits and you have to debug why :)
>
>>> +             insert_time2 = get_insert_time((insert_size * 2), mode);
>>> +             if (insert_time2 < 0)
>>> +                     goto err;
>>> +
>>> +             expected_time = (scale_factor * insert_time1 *
>>> +                              error_factor)/100;
>>> +             if (insert_time2 > expected_time) {
>>> +                     pr_err("%s fragmented insert took more %u msecs\n",
>>> +                            mode->name, insert_time2 - expected_time);
>>> +                     goto err;
>>> +             }
>>> +
>>> +             pr_info("%s fragmented insert of %u and %u insertions took %u and %u msecs\n",
>>> +                     mode->name, insert_size, insert_size * 2, insert_time1,
>>> +                     insert_time2);
> Put the info first before the error. We always want the full details,
> with the error message explaining why it's unhappy.
> -Chris
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&amp;data=02%7C01%7Cnirmoy.das%40amd.com%7C5c7df129b9cf44b3ae4008d803e84445%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637263643415833767&amp;sdata=PrCQse4nhN0ZITT9OniuHhF7A5uxJD6ehk0PMjm7WMU%3D&amp;reserved=0
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel