[PATCH v2 0/5] mm: reduce mmap_lock contention and improve page fault performance

[David Hildenbrand (Arm)]

On 5/20/26 23:15, Matthew Wilcox wrote:
> On Thu, May 21, 2026 at 05:14:20AM +0800, Barry Song wrote:
>> My understanding is that we should not blame applications here. This is 2026:
>> there are basically only two kinds of applications — single-threaded and
>> multi-threaded — and single-threaded applications are nearly extinct.
> 
> all of the applications i run are either single threaded or don't fork.
> what multithreaded applications call fork?

Traditionally the problem was random libraries using fork+execve to launch other
programs ... instead of using alternatives like posix_spwan (some use cases
require more work done before execve and cannot yet switch to that). I'd hope
that that is less of a problem on Android.

I assume Android zygote might be multi threaded? Maybe sshd as well? Systemd?
But I'd be surprised if there are really performance implications.

Not sure about webbroswers .... I think most of them switched to fork servers,
where I would assume fork servers would be single-threaded.

So, yeah, getting a clear understanding how this ends up being a problem on
Android would be great.

-- 
Cheers,

David