Re: "could not reattach to shared memory" on buildfarm member dory - Mailing list pgsql-hackers

From Andres Freund
Subject Re: "could not reattach to shared memory" on buildfarm member dory
Date
Msg-id 20180501002419.onmikldoe2ssjauq@alap3.anarazel.de
Whole thread Raw
In response to Re: "could not reattach to shared memory" on buildfarm member dory  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: "could not reattach to shared memory" on buildfarm member dory  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Him

On 2018-04-30 20:01:40 -0400, Tom Lane wrote:
> What seems like a plausible theory at this point is that the apparent
> asynchronicity is due to the allocation being triggered by a different
> thread, and the fact that our added monitoring code seems to make the
> failure more likely can be explained by that code changing the timing.
> But what thread could it be?  It doesn't really look to me like either
> the signal thread or the timer thread could eat 4MB.

It seems plausible that the underlying allocator allocates larger chunks
to serve small allocations.  But we don't seem to have started any threads
at PGSharedMemoryReAttach() time? So it'd have to be something else that
starts threads.

Heath, could you use process explorer or such to check which processes
are running inside a working backend process?

Greetings,

Andres Freund


pgsql-hackers by date:

Previous
From: Andres Freund
Date:
Subject: Re: [HACKERS] Clock with Adaptive Replacement
Next
From: Юрий Соколов
Date:
Subject: Re: [HACKERS] Clock with Adaptive Replacement