From: Marco Atzeri <marco.atzeri@gmail.com>
To: cygwin@cygwin.com
Subject: Re: cygserver - Postgres Multiple connection Load Testing - Inifinte Loop
Date: Tue, 21 Mar 2017 07:29:00 -0000 [thread overview]
Message-ID: <8fd6c531-0fdc-3c81-c932-e601cddec714@gmail.com> (raw)
In-Reply-To: <20170321025614.GA2100214@tornado.leadboat.com>
On 21/03/2017 03:56, Noah Misch wrote:
> On Tue, Aug 03, 2004 at 12:06:12PM +0200, Corinna Vinschen wrote:
>> On Aug 2 20:33, sarbx-cygwin6344@mailblocks.com wrote:
>>> This time around, cygserver does not eat CPU. But after 5 to 6
>>> concurrent
>>> connections nothing seem to work, looks kind of hung. There is no
>>> activity in the Postgres
>>> log file. Opening a new database connection also hangs. There is no
>>> activity on the machine.
>
>> Any chance to create a simple testcase which uncovers that behaviour
>> without involving a whole database system?
>
> Attached test program reproduces it on Cygwin 2.7.0, Cygwin 1.7.5, and a few
> intermediate versions. The program creates sixteen processes that each
> perform a tight loop over the following:
same on x86_64 2.8.0-0.1
>
> - select one of four semaphores
> - reduce semaphore's value from 1 to 0 ("lock" it)
> - raise semaphore's value from 0 to 1 ("unlock" it)
>
> On GNU/Linux, AIX, and Solaris, the processes keep busy and finish one million
> lock/unlock cycles apiece in a few minutes. On Cygwin, they hang within a few
> seconds and under one hundred cycles apiece. At that point, cygserver is
> unresponsive to other clients; for example, "strace /bin/true", opening a new
> Cygwin terminal, "cat /proc/sysvipc/sem" and "cygserver -S" all hang. In most
> tests, cygserver was not consuming CPU while unresponsive.
confirmed
> Thanks,
> nm
>
Regards
Marco
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next prev parent reply other threads:[~2017-03-21 7:29 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200408030333.i733XEXn023894@mx3.redhat.com>
2004-08-03 10:06 ` Corinna Vinschen
2004-08-03 20:45 ` Saravanan Bellan
2004-08-03 20:54 ` Christopher Faylor
2004-08-03 21:10 ` Saravanan Bellan
2017-03-21 2:56 ` Noah Misch
2017-03-21 7:29 ` Marco Atzeri [this message]
2017-03-24 17:52 ` Corinna Vinschen
2017-03-25 10:55 ` Marco Atzeri
2017-03-25 12:02 ` Corinna Vinschen
2017-03-25 12:31 ` Marco Atzeri
2017-03-28 5:48 ` Noah Misch
2017-04-02 2:36 ` Noah Misch
2017-05-07 3:35 ` Noah Misch
2017-05-07 4:01 ` Larry Hall (Cygwin)
2017-06-14 23:32 ` Marco Atzeri
2017-06-20 11:11 ` Corinna Vinschen
2017-06-20 17:29 ` Marco Atzeri
2017-06-21 7:58 ` Corinna Vinschen
2004-08-03 3:33 sarbx-cygwin6344
[not found] <200407302132.i6ULWwXn016838@mx3.redhat.com>
2004-08-02 9:45 ` Corinna Vinschen
-- strict thread matches above, loose matches on Subject: below --
2004-07-30 22:09 sarbx-cygwin6344
[not found] <200407290319.i6T3JCXn018245@mx3.redhat.com>
2004-07-30 13:43 ` Corinna Vinschen
2004-07-29 10:35 sarbx-cygwin6344
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