Re: cygserver - Postgres Multiple connection Load Testing - Inifinte Loop

[Marco Atzeri <marco dot atzeri at gmail dot com>]

On 07/05/2017 05:47, Larry Hall (Cygwin) wrote:
> On 05/06/2017 11:27 PM, Noah Misch wrote:
> > On Sat, Apr 01, 2017 at 10:36:24PM -0400, Noah Misch wrote:
> > > On Tue, Mar 28, 2017 at 01:26:52AM -0400, Noah Misch wrote:
> > > > On Fri, Mar 24, 2017 at 06:11:01PM +0100, Corinna Vinschen wrote:
> > > > > I pushed a patchset now, and uploaded new developer snapshots for
> > > > > testing to https://cygwin.com/snapshots/
> > > >
> > > > > Please give it a try
> > >
> > > > I call the cygwin-20170324 freezes "limited" because the symptoms
> > > > differ from
> > > > the classic freeze I described upthread.  "strace /bin/true" and "cat
> > > > /proc/sysvipc/sem" do not hang, but every PostgreSQL backend process
> > > > is stuck
> > > > waiting on a synchronization primitive.
> > > >
> > > > I can distill another self-contained test case for the limited
> > > > freeze seen in
> > > > cygwin-20170324, but that make take awhile.  I'm sending this early
> > > > report so
> > > > you're aware of the possible regression in cygwin-20170324.
> > >
> > > I'm attaching a new test program that demonstrates the regression.
> > > My previous
> > > test program created sixteen processes that each picked a random
> > > semaphore to
> > > lock.  Now, each process picks two semaphores and locks them in
> > > order.  This
> > > proceeds smoothly on GNU/Linux and on cygwin-20170321.tar.xz
> > > "cygserver -r 40".
> > > It freezes within one second on cygwin-20170324.tar.xz "cygserver -r
> > > 40".
> >
> > I suggest reverting the cygwin-20170324 cygserver changes for now.  Older
> > versions can be configured to have reliable sysv semaphores, but I
> > think no
> > settings render sysv semaphores reliable in Cygwin 2.8.0.  What do you
> > think?
>
> Just FYI, Corinna is away for a bit (in European time, "a bit" = until
> June ;-) ) so don't be surprised if her response is delayed.

as she is back, we can humble rise her attention to the matter.

Regards
Marco



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