From: arisawa <arisawa@ar.aichi-u.ac.jp>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] protection against resource exhaustion
Date: Tue, 27 Jan 2015 09:33:05 +0900 [thread overview]
Message-ID: <D6B3E614-CD6D-443E-8389-C7258D90954F@ar.aichi-u.ac.jp> (raw)
In-Reply-To: <4c37cf728d5b0e7ae4ebd3c2e0c2cee4@brasstown.quanstro.net>
Hello,
many of resource exhaustion come from careless programming.
I would like such processes to be killed immediately.
throwing up to broken state might be better.
I prefer an option to plan9.ini that enable resrcwait(), because the call breaks
traditional programming style and probably we need more time to have
right solution.
> 2015/01/26 23:13、erik quanstrom <quanstro@quanstro.net> のメール:
>
> On Mon Jan 26 03:43:36 PST 2015, arisawa@ar.aichi-u.ac.jp wrote:
>> Hello,
>>
>> I have been playing the following program.
>> I tried on official plan9, 9front, and 9atom.
>> none of them showed messages that come from:
>> sysfatal("fork: %r”);
>> sysfatal("exec: %r");
>> I suspect that
>> fork()
>> does not return -1 even if it failed in creating new process.
>
> exactly.
>
> the reason it never returns -1, is that introduces a new failure case in
> every program running, and testing seems like a huge pain. just
> testing for "handles fork returning -1" is not good enough, it has to have
> a reasonable strategy for deailing with no procs. this is hard to get right.
> just reboot. i have never been able to recover a system that hit noprocs.
> i ended up wasting people's time trying.
>
> - erik
>
> ps. how may lines like this have you seen.
>
> p = malloc(n);
> if(p == nil){
> ...
> }
>
> is this really useful in most tools?
>
next prev parent reply other threads:[~2015-01-27 0:33 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-25 6:16 arisawa
2015-01-25 6:59 ` mischief
2015-01-25 17:41 ` erik quanstrom
2015-01-26 11:47 ` arisawa
2015-01-26 12:46 ` cinap_lenrek
2015-01-26 14:13 ` erik quanstrom
2015-01-27 0:33 ` arisawa [this message]
2015-01-27 1:30 ` Lyndon Nerenberg
2015-01-27 4:13 ` erik quanstrom
2015-01-27 4:22 ` erik quanstrom
2015-01-27 7:03 ` arisawa
2015-01-27 7:10 ` Ori Bernstein
2015-01-27 7:15 ` lucio
2015-01-27 14:05 ` erik quanstrom
2015-01-27 7:12 ` lucio
2015-01-27 14:10 ` erik quanstrom
2015-01-28 0:10 ` arisawa
2015-01-28 3:38 ` erik quanstrom
2015-01-28 6:50 ` arisawa
2015-01-28 7:22 ` lucio
2015-01-28 7:48 ` Quintile
2015-01-28 13:13 ` cinap_lenrek
2015-01-28 14:03 ` erik quanstrom
2015-01-28 14:09 ` lucio
2015-01-28 14:14 ` erik quanstrom
2015-01-28 14:53 ` lucio
2015-01-28 17:02 ` Skip Tavakkolian
2015-01-28 14:16 ` erik quanstrom
2015-01-28 17:28 ` Charles Forsyth
2015-01-28 17:39 ` cinap_lenrek
2015-01-28 18:51 ` Charles Forsyth
2015-01-29 3:57 ` arisawa
2015-01-29 6:34 ` erik quanstrom
2015-01-29 6:42 ` erik quanstrom
2015-01-29 8:11 ` arisawa
2015-01-27 10:53 ` Charles Forsyth
2015-01-27 14:01 ` erik quanstrom
2015-01-25 9:04 ` arisawa
2015-01-25 11:06 ` Bence Fábián
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