Idle CPU usage
From
Alterego@VERT/ALTERANT to
Digital Man on Monday, December 16, 2019 10:14:32
Howdy,
I am planning on moving my SBBS to a low powered PC - but then I noticed it takes around 5-8%% CPU on it constantly - even while there is nobody on, and no mail transferring.
On this (old) system - with much faster CPUs it takes 2-3% constantly (which probably wouldnt normally be a problem to most).
I'm wondering why its taking up so much CPU, and if there is something I can do to reduce it? (ie: smtp/nginx uses negligble CPU while waiting for work.)
I've disabled a few services that I dont use, like web/ftp, etc with no real difference in CPU usage.
An strace, shows it doing this iteratively:
[pid 850] <... nanosleep resumed> NULL) = 0
[pid 850] select(21, [20], NULL, NULL, {0, 0}) = 0 (Timeout)
[pid 850] select(21, [20], NULL, NULL, {0, 0}) = 0 (Timeout)
[pid 850] nanosleep({0, 5000000}, <unfinished ...>
[pid 18352] <... nanosleep resumed> NULL) = 0
[pid 18352] ioctl(0, TCGETS, {B38400 opost isig -icanon -echo ...}) = 0
[pid 18352] select(1, [0], NULL, NULL, {0, 0}) = 0 (Timeout)
[pid 18352] nanosleep({0, 1000000}, NULL) = 0
[pid 18352] ioctl(0, TCGETS, {B38400 opost isig -icanon -echo ...}) = 0
[pid 18352] select(1, [0], NULL, NULL, {0, 0}) = 0 (Timeout)
[pid 18352] nanosleep({0, 1000000}, NULL) = 0
[pid 18352] ioctl(0, TCGETS, {B38400 opost isig -icanon -echo ...}) = 0
[pid 18352] select(1, [0], NULL, NULL, {0, 0}) = 0 (Timeout)
[pid 18352] nanosleep({0, 1000000}, NULL) = 0
[pid 18352] ioctl(0, TCGETS, {B38400 opost isig -icanon -echo ...}) = 0
[pid 18352] select(1, [0], NULL, NULL, {0, 0}) = 0 (Timeout)
[pid 18352] nanosleep({0, 1000000}, <unfinished ...>
[pid 850] <... nanosleep resumed> NULL) = 0
Are their ways to reduce this?
...deon
... If you've seen one city slum, you've seen them all.
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From
Rampage@VERT/SESTAR to
Tony Langdon on Wednesday, December 18, 2019 07:44:19
Re: Re: Idle CPU usage
By: Tony Langdon to Rampage on Wed Dec 18 2019 17:10:00
we had almost the same thing with gigo gating into echos and mailing
lists... there was a "secret" poster that we configured for each echo
and/or mailing list... if someone figured what it was and the proper
format of the options, they could do the same...
Hmm, I didn't think GIGO could post messages from a single user, or perhaps that came later? I remember people having to individually subscribe and be set to NOMAIL. Wasn't a big issue, because I was
the only user of gated mailing lists on my gateway.
i don't recall NOMAIL being set in my configs... i hosted some mailing lists and gated some to echos, one-way and bi-directional... there were special entries i had to make so the gating process would post to those entries and the messages would make the jump over the line... it was these special entries that could be abused if someone figured them out...
like these from my maillist.cfg:
----->8 snip 8<-----
SITE wp_e2n news ; Any mail sent to
news.group@wp_e2n.yoursite.domain gets posted
SITE wp_e2e echo ; Any mail sent to
echoname@wp_e2e.yoursite.domain gets posted
;; This is the WPT-L WPUSA TEST mailing list.
;; it is gated between
wpt-l@ftn.wpusa.dynip.com and the WPT echo
;
CAPTUREPRIV x:\gigo\WPT-L.ML X:\gigo\maillist\wpt\ wpt-l wpt-owner - WPT mlbad.txt WPT-L Mailing List
USER wpt-l BOUNCE nowpt-l.txt
EXPLODE X:\gigo\maillist\wpt\ WPT-L.ML wpt-owner -
WPT@wp_e2e.ftn.wpusa.dynip.com
;
;; This is the QCS-L general QCS support mailing list.
;; it is gated between
qcs-l@ftn.wpusa.dynip.com and the QCS_QCSML echo
;
CAPTUREPRIV x:\gigo\QCS-L.ML X:\gigo\maillist\qcs\ qcs-l qcs-owner - QCN_QCSML mlbad.txt QCS-L Mailing List
USER qcs-l BOUNCE noqcs-l.txt
EXPLODE X:\gigo\maillist\qcs\ QCS-L.ML qcs-owner -
QCN_QCSML@wp_e2e.ftn.wpusa.dynip.com
----->8 snip 8<-----
so it was SITE entries to create a domain and the list name was the user name to post to... there may be another part or two that i don't recall and don't obviously see right now but yeah, if someone figured out those user names and domains and sent mail to them, that mail would be sent directly to the echo...
)\/(ark
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