Date: Tue, 26 Mar 2024 12:46:25 -0700 From: Mark Millard <marklmi@yahoo.com> To: freebsd-hackers <freebsd-hackers@freebsd.org>, FreeBSD Mailing List <freebsd-ports@freebsd.org>, Nuno Teixeira <eduardo@freebsd.org> Subject: devel/llvm18 building example: building with BE_AMDGPU can greatly increase RAM+SWAP use compared to not Message-ID: <A5D6000A-3931-4129-9BA5-92093B30A486@yahoo.com> References: <A5D6000A-3931-4129-9BA5-92093B30A486.ref@yahoo.com>
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I've been doing some poudriere bulk testing of RAM+SWAP use
by some package build activity recently. The below is based
on using amd64 Hyper-V to run FreeBSD with 2 GiBYTes of RAM
and 4 single-thread cores. But it should give a reasonable
idea for aarch64 and indicate the direction for armv7 for
such core counts. (The amd64 Hyper-V context in use takes
far less time for an experiment, like hours instead of days
for the RPi4B overclocked and for the OrangePi+2ed .)
I started with my normal build context analogous to what I
use on aarch64 and armv7 systems:
A) BE_NATIVE instead of BE_STANDARD
B) No MLIR
The examples here are poudriere bulk single-builders,
effectively with MAKE_JOBS_NUMBER_LIMIT=4.
I use a modified version of top that tracks and reports
various MAXimum OBServed ("MaxObs") figures and a
little more.
For building with BE_AMDGPU enabled:
RAM:
1402Mi MaxObsActive
807392Ki MaxObsWired
1944Mi MaxObs(Act+Wir+Lndry)
SWAP:
5329Mi MaxObsUsed
RAM+SWAP:
6534Mi MaxObs(Act+Lndry+SwapUsed)
7089Mi MaxObs(A+Wir+L+SU) [Abbreviating more what is not additional]
7254Mi (A+W+L+SU+InAct) [Abbreviating more what is not additional]
(The 7254Mi (A+W+L+SU+InAct) is from when 7089Mi MaxObs(A+Wir+L+SU) was
live but is not a MaxObs [MAXimum OBServed] figure itself.)
The peak RAM+SWAP is during llvm-tblgen for AMDGPU related
materials.
For building with BE_AMDGPU disabled:
RAM:
1401Mi MaxObsActive
786872Ki MaxObsWired
1944Mi MaxObs(Act+Wir+Lndry)
SWAP:
1252Mi MaxObsUsed
RAM+SWAP:
2613Mi MaxObs(Act+Lndry+SwapUsed)
3160Mi MaxObs(A+Wir+L+SU) [Abbreviating more what is not additional]
3190Mi (A+W+L+SU+InAct) [Abbreviating more what is not additional]
(The 3190Mi (A+W+L+SU+InAct) is from when 3160Mi MaxObs(A+Wir+L+SU)
was live but is not a MaxObs [MAXimum OBServed] figure itself.)
The around 7254Mi/3190Mi =approx.= 2.27 suggests that low-end
build-machine activity that does not need to build BE_AMDGPU
possibly should have devel/llvm18 configured to avoid BE_AMDGPU .
Notes:
The 2 GiBytes of RAM forces memory pressure required to observe
reasonable RAM+SWAP usage figures, at least for package builds
needing a sufficient about RAM+SWAP.
===
Mark Millard
marklmi at yahoo.com
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