Arm Community
Site
Search
User
Site
Search
User
Groups
Arm Research
DesignStart
Education Hub
Graphics and Gaming
High Performance Computing
Innovation
Multimedia
Open Source Software and Platforms
Physical
Processors
Security
System
Software Tools
TrustZone for Armv8-M
中文社区
Blog
Announcements
Artificial Intelligence
Automotive
Healthcare
HPC
Infrastructure
Innovation
Internet of Things
Machine Learning
Mobile
Smart Homes
Wearables
Forums
All developer forums
IP Product forums
Tool & Software forums
Pelion IoT Platform
Support
Open a support case
Documentation
Downloads
Training
Arm Approved program
Arm Design Reviews
Community Help
More
Cancel
Developer Community
Tools and Software
Graphics and Gaming
Jump...
Cancel
Graphics and Gaming
Graphics and Gaming forum
bad performance on 3.8 kernel
Blog
Forum
Videos & Files
Help
Jump...
Cancel
New
Replies
8 replies
Subscribers
133 subscribers
Views
3842 views
Users
0 members are here
Mali Drivers
Mali-GPU
Mali-400
Related
bad performance on 3.8 kernel
Offline
Marian Mihailescu
over 7 years ago
Note: This was originally posted on 18th June 2013 at
http://forums.arm.com
Mali 400 on an exynos-based board:
with 3.0 kernel, EGL working fine, with up to 600fps in es2gears
ported drivers to 3.8 kernel, and mali acceleration working, however, the performance is roughly 50%.
I have debugged the issue at the gp job start wrapper - _mali_ukk_gp_start_job, which is called now 50% more times than on the 3.0 kernel...
Here is a comparison between the 2 kernels:
1) with SKIP_GP_JOBS and retuning the job straight away from _mali_ukk_gp_start_job, both 3.0 and 3.8 kernel results in the same number of mali_ioctl calls and the same performance - 650fps in es2gears
2) i modified es2gears to stop after 600 frames and here are my results (from bottom to top):
GP jobs actually done - calls to "mali_gp_job_start": 299 on 3.0 kernel, 302 on 3.8 kernel
calls to mali_group_start_gp_job (which calls mali_gp_job_start): 299 on 3.0, 302 on 3.8 kernel
executions of mali_gp_scheduler_schedule (which calls mali_group_start_gp_job): 299 on 3.0, 302 on 3.8 kernel -- appears as "mali_gp_scheduler_schedule() {" in ftrace
calls to mali_gp_scheduler_schedule: 0 on 3.0, 299 on 3.8 kernel -- appears as "mali_gp_scheduler_schedule();" in ftrace
system calls served (mali_ioctl) : 960 on 3.0 kernel, 1373 on 3.8 kernel
results: ~600fps on 3.0 kernel, ~380fps on 3.8 kernel
So the conclusion is that the slowdown is due to a much larger number (almost double) of mali_ioctls for MALI_IOC_GP2_START_JOB.
Since I don't have the code for libMali to debug why exactly it's making so many syscalls, I hope somebody here can help me and give me an idea where to look.
A strange thing is the job numbers assigned.
In the 3.0 kernel, they are all multiples of 4, like: Mali GP scheduler: Job 2405 (0xE6581B80) queued; 2409, 2413, 2417, 2421, 2425, ...
In the 3.8 kernel, they increment either by 2, 4 or 6: 8825, 8829, 8833, 8835, 8841, 8843, 8849, 8853, ...
More questions in this forum
By title
By date
By reply count
By view count
By most asked
By votes
By quality
Descending
Ascending
All recent questions
Unread questions
Questions you've participated in
Questions you've asked
Unanswered questions
Answered questions
Questions with suggested answers
Questions with no replies
Answered
Analyzing optimized SPIR-V binaries using Mali Offline Compiler
0
Mali Offline Compiler
vulkan
Arm Mobile Studio
5672
views
4
replies
Latest
2 months ago
by
speedym
Answered
Understanding Mali Perf Counters in Streamline
0
arm streamline
Mali-G77
6068
views
2
replies
Latest
2 months ago
by
Peter Harris
Answered
GPU Benchmark Tools Recommendation
+1
GPU Tools
OpenGL ES
performance analysis
Mali-G76
9391
views
2
replies
Latest
3 months ago
by
Vikash
Answered
I want to know about the GPU Line up
+1
GPU Architecture
Mali GPU (Bifrost Architecture)
gpu
10254
views
5
replies
Latest
3 months ago
by
Peter Harris
Not Answered
Mali-G71 GPU glReadPixels slow compared to linux desktop equivilant for Default Framebuffer
+1
Android OpenGL ES
Mali-G71
Graphics APIs
5936
views
0
replies
Started
3 months ago
by
Matthew Good
<
>
View all questions in Graphics and Gaming forum