On Thu, Apr 22, 2021 at 03:38:53PM +0200, Martin Pieuchot wrote:
> Diff below remove the KERNEL_LOCK()/UNLOCK() dance from uvm_fault() for
> both amd64 and sparc64.  That means the kernel lock will only be taken
> for lower faults and some amap/anon code will now run without it.
> 
> I'd be interested to have this tested and see how much does that impact
> the build time of packages.

I did measure kernel build time make -j 4 on a 4 core machine.
System time goes down by 7.7%, real time stays the same.

http://bluhm.genua.de/perform/results/2021-04-25T17%3A18%3A32Z/gnuplot/make.html
left column current, righ column with uvm unlock diff

http://bluhm.genua.de/perform/results/2021-04-25T17%3A18%3A32Z/perform.html
see row time -lp make -CGENERIC.MP -j4 -s

http://bluhm.genua.de/files/kstack-make.svg
http://bluhm.genua.de/files/kstack-make-uvm.svg
I cannot see much difference here.

bluhm

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