Conversation

Andy Sloane
@a1k0n
I have a WearOS watch which is a frustratingly janky piece of crap. Whenever you try to do anything on it, it freezes for several seconds. Why? because it's SWAPPING! what the what?! 1.9G of virtual memory for a daemon on a wristwatch? 21 java apps, each with >760M vmem? JFC
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Andy Sloane
@a1k0n
Replying to
@joshu
Right, but it's relying way too hard on the virtual memory mechanism to maintain the working set. The load average spikes >10 if I do something crazy like load the settings menu.
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Daniel Micay
@DanielMicay
Replying to
@a1k0n
and
@joshu
The issue is definitely not virtual memory usage. You can't really determine much from VIRT. Each mapping uses a small amount of memory, but larger mappings don't consume more resources. The design approach they use is to share tons of potentially used data via memory mappings.
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Daniel Micay
@DanielMicay
Replying to
@DanielMicay
@a1k0n
and
@joshu
In the default optimized spawning model, each app is forked from the Zygote, which preloads all the commonly used Java and native libraries including running their initialization code. It's a startup time and memory use optimization. It uses more actual memory with it disabled.
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Daniel Micay
@DanielMicay
Replying to
@iamtommythorn
@a1k0n
and
@joshu
Whatever is wrong, I don't see a way it could be connected to the virtual memory usage. A lot of that would be from stuff like the Control Flow Integrity shadow mapping which reserves a ton of address space as PROT_NONE to guarantee it has contiguous space for all possible needs.
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