Comment 72 for bug 1833281

Created attachment 284677
log of read_vmstat when filling RAM with new tabs in Chromium

(In reply to Michal Hocko from comment #8)
> Created attachment 258067 [details]
> read_vmstat.c
>
> On Tue 22-08-17 15:55:30, Andrew Morton wrote:
> >
> > (switched to email. Please respond via emailed reply-to-all, not via the
> > bugzilla web interface).
> >
> > On Tue, 22 Aug 2017 11:17:08 +0000 <email address hidden>
> wrote:
> [...]
> > Sadly I haven't been able to capture this information
> > > fully yet due to said unresponsiveness.
>
> Please try to collect /proc/vmstat in the bacground and provide the
> collected data. Something like
>
> while true
> do
> cp /proc/vmstat > vmstat.$(date +%s)
> sleep 1s
> done
>
> If the system turns out so busy that it won't be able to fork a process
> or write the output (which you will see by checking timestamps of files
> and looking for holes) then you can try the attached proggy
> ./read_vmstat output_file timeout output_size
>
> Note you might need to increase the mlock rlimit to lock everything into
> memory.

I am facing the following issue on this [1] hardware:
- when new tabs are openned in Chromium, swap (on SSD) is not used, 0K of swap is used. After about 2.5 GB out of total 4 GB RAM becomes used, about 15-50 MB of swap can be used, sometimes up to ~570 MB, but not more;
- this leads to that Load Everage bumps from normal ~0.9 to 9-15 when loading a new tab in Chromium;
- so the system in general freezes from time to time when working in the web browser and switching between tabs and/or openning new ones

I have run your program read_vmstat (./read_vmstat vmstat.log 5s) and then ran a script that openned many tabs in Chromium, a new tab each 5s; after all tabs were openned, about ~3.5 GB of RAM became used, but only about 15 MB were swapped; then I ctrl+c'ed ./read_vmstat. Collected log is attached.

Kernel was 4.15.0-58-generic in Ubuntu.

[1] https://linux-hardware.org/?probe=414558f152