Date: Thu, 29 Feb 2024 10:04:03 -0800 From: Mark Millard <marklmi@yahoo.com> To: freebsd-hackers <freebsd-hackers@freebsd.org>, FreeBSD ARM List <freebsd-arm@freebsd.org> Subject: Re: How to investigate an unexpected port build time-taken relationship in an aarch64 context? Message-ID: <F5D20FC4-BF9D-4790-B3D3-0FA215B3F254@yahoo.com> In-Reply-To: <900B51D1-2005-4281-BFBD-96B49B147A13@yahoo.com> References: <7D640D5A-7514-480E-8D5B-58003DB558E1@yahoo.com> <900B51D1-2005-4281-BFBD-96B49B147A13@yahoo.com>
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[A different test case also gets the shorter time frame.] On Feb 28, 2024, at 22:59, Mark Millard <marklmi@yahoo.com> wrote: > On Feb 28, 2024, at 18:46, Mark Millard <marklmi@yahoo.com> wrote: >=20 >> Example HW Context: Windows Development Kit 2023 >> 8 cores: 4 cortex-A78C's and 4 cortex-X1C's >> Headless: serial console and ssh access, no x11 or the like = installed. >> UFS use. >>=20 >> Note: cortex-A76's are missing 3 or so instruction set >> features compared to A78C/X1C parts. Use of >> -mcpu=3Dcortex-a76 generated code is compatibile (and would allow >> the code to run on a cortex-a76 system, such as an RPi5 once >> supported). >>=20 >> I've been doing poudriere-devel bulk timing experiments based on: >>=20 >> A) PkgBase based system software (kernel and world) and >> general use of default code generation for ports and >> such. >>=20 >> B) A personal -mcpu=3Dcortex-a76 based kernel, world, port builds >> (into packages via poudriere-devel). >>=20 >> C) Also use of an armv7 poudriere jail based on armv7 PkgBase >> and default armv7 code generation. This was used in both the >> (A) and (B) contexts. These also show what I'm curious about. >>=20 >> Using the armv7 poudriere jail context for illustration: >>=20 >> For (B) used via the armv7 context: >>=20 >> [05:40:24] [03] [04:55:38] Finished lang/rust | rust-1.76.0: Success >> . . . >> [05:45:58] [01] [05:01:12] Finished devel/llvm18@default | = llvm18-18.1.0.r3: Success >> [05:46:00] [01] [00:00:00] Building devel/boost-libs | = boost-libs-1.84.0 >> [06:59:23] [01] [01:13:23] Finished devel/boost-libs | = boost-libs-1.84.0: Success >>=20 >> For (A) used via the armv7 poudriere jail context: >>=20 >> [06:33:21] [01] [05:40:48] Finished lang/rust | rust-1.76.0: Success >> . . . >> [06:40:05] [05] [05:48:09] Finished devel/llvm18@default | = llvm18-18.1.0.r3: Success >> [06:40:07] [01] [00:00:00] Building devel/boost-libs | = boost-libs-1.84.0 >> [06:57:48] [01] [00:17:41] Finished devel/boost-libs | = boost-libs-1.84.0: Success >>=20 >> The curiosity is about the 01:13:23 vs. 00:17:41 boost-libs: The >> ratio is large and in the opposite direction to most time trends. >>=20 >> Notes: Almost all the time llvm18 and rust were building, both were >> building but little else did and the load average was 16+ from the >> llvm18/rust build activity. When boost-libs was building it was the >> only thing building and it looked to be single threaded when I >> was watching. >=20 > I should have been explicit that the 01:13:23 was mostly > "stage" phase (not "build" phase) and I was referring to > the "stage" phase as far as single threaded is concerned. >=20 >> (A) and (B) without use of the armv7 context got similar results >> when I first noticed this but I'm going back and recording times >> for some variations. I do not have those to report other >> pairs of results yet. >>=20 >> (In the armv7 poudriere jail context reported:) >> (B) takes less time for llvm18 and rust than (A) does. >> (A) takes vastly less time for boost-libs than (B) does, >> approximately a factor of 4 for the time-ratio. >>=20 >> I'd be curious to get a clue what contributes to the boost-libs >> time ratio being so extreme once I have figures for other >> combinations of poudriere jail content vs. the system's content. >=20 > Turns out that for the aarch64 jail (PkgBase system and > default code generation), stage started about 10 min into > the boost-libs activity. Package started somewhat under 5 > minutes later. End result: >=20 > [05:55:56] [03] [05:33:12] Finished lang/rust | rust-1.76.0: Success > . . . > [06:04:37] [01] [05:41:53] Finished devel/llvm18@default | = llvm18-18.1.0.r3: Success > [06:04:39] [01] [00:00:00] Building devel/boost-libs | = boost-libs-1.84.0 > [06:20:50] [01] [00:16:11] Finished devel/boost-libs | = boost-libs-1.84.0: Success >=20 > So, very similar to the armv7 jail result for a PkgBase > system context (aarch64 boot and aarch64/armv7 PkgBase > jail, default code generation). >=20 > It appears that the boost-libs "stage" phase is the context > for my question. >=20 > For the jail code generation being based on -mcpu=3Dcortex-a76 > code generation but the boot having been PkgBase based: >=20 > Stage started about 11.5 min into the boost-libs activity. > Package started around 48 minutes later. End result > (showing only boost-libs): >=20 > [01:07:01] [01] [01:06:31] Finished devel/boost-libs | = boost-libs-1.84.0: Success >=20 > I'll note that bjam stays around 100% CPU in top during this > much longer "stage" phase. Definitely less than the 01:13:23 > time. MWCHAN "-", STAT RJ, PRI 135 when I looked. >=20 > For the jail code generation and boot context both being based > on -mcpu=3Dcortex-a76 code generation: >=20 > [05:16:38] [01] [00:49:22] Finished devel/boost-libs | = boost-libs-1.83.0_1: Success >=20 > Also definitely less than the 01:13:23 time. (I'm showing here an > earlier test when it was boost-libs v1.83.) >=20 > A ZFS context (instead of UFS context) showed: >=20 > [04:37:47] [03] [04:03:16] Finished lang/rust | rust-1.76.0: Success > . . . > [04:43:47] [01] [04:09:16] Finished devel/llvm18@default | = llvm18-18.1.0.r3: Success > [04:43:48] [01] [00:00:00] Building devel/boost-libs | = boost-libs-1.84.0 > [05:41:46] [01] [00:57:58] Finished devel/boost-libs | = boost-libs-1.84.0: Success Another test case . . . So I booted the -mcpu-cortex-a76 kernel and world (kernel configures to use LSE atomics) and chroot'd into a aarch64 PkgBase world that has a PkgBase jail for poudiere use and that uses default code generation. Stage started about 9 min into the boost-libs activity. Package started around 4.5 minutes later. End result (showing only boost-libs): [00:15:56] [01] [00:15:48] Finished devel/boost-libs | = boost-libs-1.84.0: Success =3D=3D=3D Mark Millard marklmi at yahoo.com
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