"sched_setaffinity: Invalid argument"?

[LaurV]

I am using an app to control cpu/gpu frequencies and to show temperatures in a 10-core CPU on ubuntu. It is also called "core-ctl-something" (note, I am not at home right now to check, and generally I am a linux noob, only using it in some mining rig because mining is faster, R-vii windows drivers suck) - anyhow, maybe this info helps somehow, or give somebody some idea: on the chart which shows the cores' temps, the cores are numbered 0,1,2,3,4,8,9,10,11,12. Don't ask me why...
(edit, it looks indeed like a crippled 16-cores CPU, or maybe it is like that, internally).

[ewmayer]

Originally Posted by LaurV

I am using an app to control cpu/gpu frequencies and to show temperatures in a 10-core CPU on ubuntu. It is also called "core-ctl-something" (note, I am not at home right now to check, and generally I am a linux noob, only using it in some mining rig because mining is faster, R-vii windows drivers suck) - anyhow, maybe this info helps somehow, or give somebody some idea: on the chart which shows the cores' temps, the cores are numbered 0,1,2,3,4,8,9,10,11,12. Don't ask me why...
(edit, it looks indeed like a crippled 16-cores CPU, or maybe it is like that, internally).

The OP's case is different in that his /proc/cpuinfo shows core numbers 0-7, as expected. But yes, especially Intel sometimes uses utterly bizarre internal numbering - I've integrated the hwloc package into the current Mlucas dev-branch to automatically handle such weirdness. The command-line version of hwloc is, oddly, named 'lstopo' - attached is its visual rendering of the topology for another Intel chip, a 61c244t Knights Corner copro CPU - in the rendering, the grey-shaded "Core L#--" entries are physical cores, "P#--" are the attached logical cores in Intel's numbering (the one which is used to generate the /proc/cpuinfo data), and "PU L#--" are the hwloc-reindexed logical cores. Check out Intel's numbering of the 4 logical cores mapped to physical core 0, for instance:

[leonardyan96]

I just found, for a Snapdragon 835 the best way is using 2 instances. One for big cores and one for small cores. When using -cpu 0:3 or 4:7 the selftest in the middle range can be finished within less than 30 min, but with one instance using all 8 cores, it takes several hours! I'm not sure whether I ignored anything or not.

[ewmayer]

Originally Posted by leonardyan96

I just found, for a Snapdragon 835 the best way is using 2 instances. One for big cores and one for small cores. When using -cpu 0:3 or 4:7 the selftest in the middle range can be finished within less than 30 min, but with one instance using all 8 cores, it takes several hours! I'm not sure whether I ignored anything or not.

Interesting, thanks. Do you now have 2 production-run instances running on the respective 4-core subsets, and if so, what are the respective exponents/runtimes? On Galaxy S7 with its hybrid quadcore (2 big, 2 little) I get quite good performance from running 1 instance on all 4 cores, so the big/little disparity must be significantly greater on 835. What are the basic (e.g. as per /proc/cpuinfo) data for the 2 different types of cores on the 835?

I see the 835 first appeared in Galaxy S8, which is by now old enough that still-functioning for-parts one should be gettable reasonably cheaply. Here the roadmap for the processor series, from Wikipedia:

In early 2016, Qualcomm launched the Snapdragon 820, an ARM 64-bit quad-core processor using in-house designed Kryo cores. Qualcomm launched an updated Snapdragon 821 later in the year with higher clock speeds and slightly better performance. The Snapdragon 820 family uses Samsung's 14-nanometer FinFET process. Qualcomm also released the Qualcomm Snapdragon Neural Processing Engine SDK which was the first AI acceleration on smartphones.[62]

Qualcomm announced the octa-core Snapdragon 835 SoC on 17 November 2016. Released the following year, it uses Kryo 280 cores and is built using Samsung's 10-nanometer FinFET process. At initial launch, due to Samsung's role in manufacturing the chip, its mobile division also acquired the initial inventory of the chip. That means that no other phone maker was able to manufacture products containing the Snapdragon 835 until Samsung released its flagship device of the year, the Galaxy S8.[63]

At Computex 2017 in May, Qualcomm and Microsoft announced plans to launch Snapdragon-based laptops running Windows 10. Qualcomm partnered with HP, Lenovo, and Asus to release slim portables and 2-in-1 devices powered by the Snapdragon 835.[64]

In December 2017, Qualcomm announced the octa-core Snapdragon 845. It uses the same 10-nanometer manufacturing process as the earlier Snapdragon 835 but introduced a new processor architecture, Kryo 385,[65] designed for better battery life, photography, and for use with artificial intelligence apps.[66][65]

In early 2018, Qualcomm introduced the 7 series, which sits between the 6 and 8 series in terms of pricing and performance. The 700 launched with octa-core models Snapdragon 710 and 712, using the Kryo 360 processor architecture, and built on a 10-nanometer manufacturing process.[67][68][69]

In 2019, Qualcomm released new variants of its mobile processors, with the Snapdragon 855 replacing the 845. The Snapdragon 855 competes against other high end system-on-chip solutions like the Apple A12, and Kirin 980. The Snapdragon 855 features Kryo 485 cores, built on TSMC's 7-nanometer process.[70] The Snapdragon 730 and 730G replaced the 710 and 712. The newer 730 and 730G feature Kryo 460 cores, built on Samsung's 8-nanometer process.[71]

In December 2019, Qualcomm announced the Snapdragon 865 and Snapdragon 765, which succeeded the Snapdragon 855/855+ and Snapdragon 730/730G respectively. The Snapdragon 765 has integrated 5G, while the Snapdragon 865 is assisted by a separate Qualcomm X55 5G modem. Despite lacking integrated 5G, the Snapdragon 865 is incompatible with 4G phones.[72][73]

In May 2020, Qualcomm announced the new Snapdragon 768G 5G processor, an upgraded version of the 765G processor. The main difference between the 765G and 768G is that the 768G will offer 15 percent increase in performance and higher clock speed on the CPU, up to 2.8 GHz from 2.4 GHz.[74]

In September 2020, Qualcomm unveiled the Snapdragon 750G processor, the latest addition to the 7-series, designed to bring 5G support for low-latency mobile gaming.[75]

In December 2020, Qualcomm unveiled the Snapdragon 888. The major differences compared to the 865/+ is a new core, designed by ARM, the ARM Cortex X1, support for LPDDR5-6400 and a built in 5G modem, meaning the X55 Modem is not required. The 888 is based on Samsung 5nm, with a TDP of 5 watts, but this can be altered by the manufacturer.[76]

[leonardyan96]

All of them are p-1 works in worktodo.ini, not selftests
Running only 1 instance for 4 big cores: M115762417 S1 140ms/iter
Running only 1 instance for 4 small cores: M115762483 S1 230ms/iter
If running 2 instances for 2 core groups the timings are quite close to the figures above.
Running 1 instance for all 8 cores: M115762417 S1 115ms/iter

[leonardyan96]

Cell:/ $ cat /proc/cpuinfo
Processor       : AArch64 Processor rev 4 (aarch64)
processor       : 0
BogoMIPS        : 38.40
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x51
CPU architecture: 8
CPU variant     : 0xa
CPU part        : 0x801
CPU revision    : 4

processor       : 1
BogoMIPS        : 38.40
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x51
CPU architecture: 8
CPU variant     : 0xa
CPU part        : 0x801
CPU revision    : 4

processor       : 2
BogoMIPS        : 38.40
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x51
CPU architecture: 8
CPU variant     : 0xa
CPU part        : 0x801
CPU revision    : 4

processor       : 3
BogoMIPS        : 38.40
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x51
CPU architecture: 8
CPU variant     : 0xa
CPU part        : 0x801
CPU revision    : 4

processor       : 4
BogoMIPS        : 38.40
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x51
CPU architecture: 8
CPU variant     : 0xa
CPU part        : 0x800
CPU revision    : 1

processor       : 5
BogoMIPS        : 38.40
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x51
CPU architecture: 8
CPU variant     : 0xa
CPU part        : 0x800
CPU revision    : 1

processor       : 6
BogoMIPS        : 38.40
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x51
CPU architecture: 8
CPU variant     : 0xa
CPU part        : 0x800
CPU revision    : 1

processor       : 7
BogoMIPS        : 38.40
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x51
CPU architecture: 8
CPU variant     : 0xa
CPU part        : 0x800
CPU revision    : 1

Hardware        : Qualcomm Technologies, Inc MSM8998

[leonardyan96]

According to /sys/devices/system/cpu/cpufreq, the small cores top at 1.90Ghz and the big cores top at 2.46GHz.