Re:Tacit knowledge is more important than deliberate practice
by hinkley on Monday December 13, 2021 @11:19AM
(#29540958)
One of my weirdest fixes was removing a duplicate database request on an admin page that was taking 30 seconds to load. But instead of dropping to 15 seconds, the response time dropped to 3 seconds.
I've also removed a lot of 10% calls that improved performance by 20%. Profilers don't show the cost of your code to the CPU and Virtual Memory caches. And there are new or malloc calls whose full cost is paid by another thread due to the tempo of the allocations.
As you say, looking at the count column is a huge thing. But the biggest failure I've seen is one of imagination. So many people give up when the last tall tent pole has been addressed. Even if we've only hit a 3rd of our performance goal, they believe they've tried everything and we should move on. Nobody knows how to do perf analysis with a budget. For instance, the 'current users' count should not be entitled to 10% of the page load time.
I've also removed a lot of 10% calls that improved performance by 20%. Profilers don't show the cost of your code to the CPU and Virtual Memory caches. And there are new or malloc calls whose full cost is paid by another thread due to the tempo of the allocations.
As you say, looking at the count column is a huge thing. But the biggest failure I've seen is one of imagination. So many people give up when the last tall tent pole has been addressed. Even if we've only hit a 3rd of our performance goal, they believe they've tried everything and we should move on. Nobody knows how to do perf analysis with a budget. For instance, the 'current users' count should not be entitled to 10% of the page load time.