Re: Very long-running buildworld process

On Wed, Jun 11, 2025 at 09:31:54PM -0700, Mark Millard wrote:
> On Jun 11, 2025, at 07:08, bob prohaska <[email protected]> wrote:
> 
> > On Tue, Jun 10, 2025 at 10:24:26PM -0700, Mark Millard wrote:
> >> On Jun 10, 2025, at 20:59, bob prohaska <[email protected]> wrote:
> >> 
> >>> Buildworld for -current on a Pi2B is strangely slow. The machine is responsive,
> >>> but seems to make no (or very slow) progress:
> >>> 
> >>> 
> >>> login: Jun  7 22:51:31 www su[3032]: bob to root on /dev/pts/0
> >>> 
> >>> 
> >>> FreeBSD/arm (www.zefox.org) (ttyu0)
> >>> 
> >>> login: bob
> >>> Password:
> >>> Last login: Sat Jun  7 22:51:25 from gateway.zefox.net
> >>> FreeBSD 15.0-CURRENT #85 main-d8773fdcbfa3: Fri Jun  6 14:17:58 PDT 2025     [email protected]:/usr/obj/usr/src/arm.armv7/sys/GENERIC
> >>> 
> >>> Welcome to FreeBSD!
> >>> 
> >>> Release Notes, Errata: https://www.FreeBSD.org/releases/
> >>> Security Advisories:   https://www.FreeBSD.org/security/
> >>> last pid: 34625;  load averages:    1.01,    1.01,    1.00                                                             up 2+22:03:17  20:45:47
> >>> last pid: 34628;  load averages:    1.07,    1.02,    1.01                                                             up 2+22:05:21  20:47:51
> >>> 45 processes:  2 running, 43 sleeping
> >>> CPU: 25.0% user,  0.0% nice,  0.0% system,  0.0% interrupt, 75.0% idle
> >>> Mem: 6196K Active, 297M Inact, 174M Wired, 98M Buf, 443M Free
> >>> Swap: 1770M Total, 422M Used, 1348M Free, 23% Inuse
> >> 
> >> Free  443M
> >> Inact 297M
> >> Wired 174M
> >> 
> >> Yet:
> >> 
> >> c++ RES is just 17M and Active is just 6196K.
> >> 
> >> Also: 422M SWAP used.
> >> 
> >> I suggest sorting the top output by (decreasing) RES and
> >> seeing if that shows what is contributing to Inact 297M
> >> as part of RESident memory use.
> >> 
> > 
> > Changing order to res yields in part:
> > last pid: 37994;  load averages:    1.01,    1.01,    1.00                                                             up 3+07:55:55  06:38:25
> > 45 processes:  2 running, 43 sleeping
> > CPU: 24.6% user,  0.0% nice,  0.3% system,  0.0% interrupt, 75.2% idle
> > Mem: 5672K Active, 307M Inact, 150M Wired, 73M Buf, 459M Free
> > Swap: 1770M Total, 422M Used, 1348M Free, 23% Inuse
> > 
> >  PID USERNAME    THR PRI NICE   SIZE    RES STATE    C   TIME    WCPU COMMAND
> > 21654 root          1 135    0   561M    17M CPU2     2  49.6H 100.12% c++
> > 37994 bob           1  20    0  6664K  3088K CPU3     3   0:00   0.19% top
> > 2951 root          1  20    0    11M  1840K select   0   0:28   0.02% sendmail
> > 2843 root          1  20    0  4684K   756K select   0   2:14   0.02% powerd
> > 3044 root          1  20    0  5920K   848K select   0   0:08   0.00% make
> 
> Hmm. May be:
> 
> # ps -axldww
> 
> might show something that would prove interesting?
I've placed the output at
http://www.zefox.net/~fbsd/rpi2/20250612/ps-axldww.log
It's too wide to view on the list. It shows the complete
(very long) command line for the offending PID.

> 
> As for watching the specific c++ process, may be
> you might temporarily run (output goes to stderr):
> 
> # truss -fae -p 21654
> 
> then ^C it. From this you would learn if the kernel is
> in use via system calls and what kinds of system calls.
> 
> (I picked truss for simpliicty vs. ktrace and kdump use.)
>
 
Near as I can tell, truss produces zero output after running
for a couple of minutes.

Thanks for writing!
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