Re: [PATCH 0/3] get_abi: improve message output and fix a regression

Em Tue, 28 Sep 2021 14:27:39 +0200
Mauro Carvalho Chehab [off-list ref] escreveu:

Em Tue, 28 Sep 2021 13:04:22 +0200
Greg Kroah-Hartman [off-list ref] escreveu:

quoted

On Tue, Sep 28, 2021 at 12:14:01PM +0200, Mauro Carvalho Chehab wrote:  

quoted

Hi Greg,

As promised on

	https://lore.kernel.org/lkml/20210928120304.62319fba@coco.lan/T/#u (local)

I'm adding progress info when  get_abi.pl is checking for undefined ABI symbols
on patches 1 and 2.

That will help not only to identify what is causing delays on the script, but also
to notify the user that processing it could take some time on some systems.

If you run it on your big server with:

  scripts/get_abi.pl undefined 2>logs

The "logs" file will contain timestamps relative to the time the script started to
do the regex matches for sysfs files. It should be printing one line every
time the progress completes 1% or one second after the last progress output.    

Adding more debugging and tweaking the script a bit to show the file it
is about to check, not the one it finished checking,  

Feel free to modify the script and add such debug/tweaks if you find
it useful. 

quoted

I got the following
debug output that seems to pinpoint the problem file.

The sysfs file that is causing problems is:
	/sys/devices/pci0000:40/0000:40:00.2/iommu/ivhd1/amd-iommu/cap

Btw, I just got an arm64 server with 128 CPUs for testing. I'm trying
to allocate also a big x86 server here, but I'm not sure if it is AMD or
Intel.

Some tests on a Gigabyte R182-Z91-00 server, equipped with AMD EPYC 7352 
24-Core Processors (total 96 threads):

	$ find /sys |wc -l
	233981

	$ time ./scripts/get_abi.pl undefined >undefined 2>logs

	real	0m38.917s
	user	0m34.554s
	sys	0m4.292s

PS.: this machine doesn't have anything at /sys/class/iommu.

On a Huawei TaiShan 200 (Model 2280) with 128 ARM cores:

	$ find /sys |wc -l
	99362
	$ time ./scripts/get_abi.pl undefined >undefined 2>logs

	real	0m29.311s
	user	0m26.173s
	sys	0m3.061s

Both machines are using Perl 5.26.

Thanks,
Mauro