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Comment by jmull | Hacker News Reader

> it's syscall heavy workloads targeting fast devices, like database software on PCIe SSDs, that will suffer the greatest slowdowns.

That's not exactly a common scenario for macOS, much less iOS devices.

It's fair to call for benchmarks that are more representative of common workloads, not less representative.

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Avid Media Composer, one of the most popular non-linear video editors in the industry, does a stat of every piece of media referenced in every project you have open when you change focus from another application back to Avid Media Composer.

Since I work on network attached storage for video editing, I'm acutely aware of how much slowing down a few simple syscalls by just a little bit can be for certain very commonly used applications on macOS.

> I'm acutely aware of how much slowing down a few simple syscalls by just a little bit

I'm going to go out on a limb here and say that a NAS isn't slowing things down "just a little bit". It'll be more on the order of a million times slower, for those operations.

It's always nice to keep this popular latency table in mind: http://norvig.com/21-days.html#answers

I would not expect that use case to be affected much. Network latency is too large, relatively speaking, and I don’t think that is “syscall heavy”, even if it does a thousand stat calls.

Syscalls are complex beasts, the patches for Meltdown only affect the bit where you transition between userspace and kernel space - this a static cost. Thus, when Avid Media Composer stats a few hundred files on a NAS far, far away from your CPU, the performance cost these patches incur will be negligible.

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