Protip: New on the job and want to establish a reputation quickly? Find the most common path and fire a profiler at it as early as you can. The odds that there's some trivial win that will accelerate the code by huge amounts is fairly decent.
Another bit of evidence developers rarely profile their code is that I can tell my mental model of how expensive some server process will be to run and most other developer's mental models tend to differ by at least an order of magnitude. I've had multiple conversations about the services I provide and people asking me what my hardware is, expecting it to be run on some monster boxes or something when I tell them it's really just two t3.mediums, which mostly do nothing, and I only have two for redundancy. And it's not like I go profile crazy... I really just do some spot checks on hot-path code. By no means am I doing anything amazing. It's just... as you write more code, the odds that you accidentally write something that performs stupidly badly goes up steadily, even if you're trying not to.
I've found that a profiler isn't even needed to find significant wins in most codebases. Simple inspection of the code and removal of obviously slow or inefficient code paths can often lead to huge performance gains.
It’s so painful to behold.
Binary formats converted to JSON blobs, each bigger than my first hard drive (!), and then back again, often multiple times in the same process.
Apple will definitely give all the necessary tools as part of Xcode for iOS/MacOS software optimisation.
AWS is going to be more interesting – this is a great opportunity for them to provide distributed profiling/tracing tools (as a hosted service, obviously) for Linux that run across a fleet of Graviton instances and help you do fleet-wide profile guided optimizations.
We should also see a lot of private companies building high-performance services on AWS to contribute to highly optimized open-source libraries being ported to graviton.
I found it to have quite a lot of useful pointers. Specifically –https://static.docs.arm.com/swog309707/a/Arm_Neoverse_N1_Sof...
https://static.docs.arm.com/ddi0487/ea/DDI0487E_a_armv8_arm....
- these two docs gives lot of useful information.
And the repo itself contain a number of examples (like ffmpeg) that have been optimized based on these manuals.
I partially agree with you though, as the penetration of Arm goes deeper into the programmer ecosystem, any mental roadblocks about deploying to Arm will disappear. It is a mindset issue, not a technical one.
In the 80s and 90s there were lots of alternative architectures and it wasn't a big deal, granted the software stacks were much much smaller and more metal. Now they are huge, but more abstract and farther away from machine issues.