Date: Thu, 12 Sep 2019 17:42:00 -0700 (PDT) From: Don Lewis <truckman@FreeBSD.org> To: Mark Johnston <markj@freebsd.org> Cc: FreeBSD Current <freebsd-current@freebsd.org>, kib@freebsd.org Subject: Re: spurious out of swap kills Message-ID: <tkrat.1a0e98a230c1a223@FreeBSD.org> In-Reply-To: <20190913000635.GG8397@raichu> References: <tkrat.84b3295682c83162@FreeBSD.org> <20190913000635.GG8397@raichu>
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On 12 Sep, Mark Johnston wrote:
> On Thu, Sep 12, 2019 at 04:00:17PM -0700, Don Lewis wrote:
>> My poudriere machine is running 13.0-CURRENT and gets updated to the
>> latest version of -CURRENT periodically. At least in the last week or
>> so, I've been seeing occasional port build failures when building my
>> default set of ports, and I finally had some time to do some
>> investigation.
>>
>> It's a 16-thread Ryzen machine, with 64 GB of RAM and 40 GB of swap.
>> Poudriere is configured with
>> USE_TMPFS="wrkdir data localbase"
>> and I have
>> .if ${.CURDIR:M*/www/chromium}
>> MAKE_JOBS_NUMBER=16
>> .else
>> MAKE_JOBS_NUMBER=7
>> .endif
>> in /usr/local/etc/poudriere.d/make.conf, since this gives me the best
>> overall build time for my set of ports. This hits memory pretty hard,
>> especially when chromium, firefox, libreoffice, and both versions of
>> openoffice are all building at the same time. During this time, the
>> amount of space consumed by tmpfs for /wrkdir gets large when building
>> these large ports. There is not enough RAM to hold it all, so some of
>> the older data spills over to swap. Swap usage peaks at about 10 GB,
>> leaving about 30 GB of free swap. Nevertheless, I see these errors,
>> with rustc being the usual victim:
>>
>> Sep 11 23:21:43 zipper kernel: pid 16581 (rustc), jid 43, uid 65534, was killed: out of swap space
>> Sep 12 02:48:23 zipper kernel: pid 1209 (rustc), jid 62, uid 65534, was killed: out of swap space
>>
>> Top shows the size of rustc being about 2 GB, so I doubt that it
>> suddenly needs an additional 30 GB of swap.
>>
>> I'm wondering if there might be a transient kmem shortage that is
>> causing a malloc(..., M_NOWAIT) failure in the swap allocation path
>> that is the cause of the problem.
>
> Perhaps this is a consequence of r351114? To confirm this, you might
> try increasing the value of vm.pfault_oom_wait to a larger value, like
> 20 or 30, and see if the OOM kills still occur.
I wonder if increasing vm.pfault_oom_attempts might also be a good idea.
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