Date: Fri, 15 Jun 2018 05:03:58 -0400 From: Mark Johnston <markj@freebsd.org> To: Kurt Jaeger <lists@opsec.eu> Cc: FreeBSD current <freebsd-current@freebsd.org> Subject: Re: swapping is completely broken in -CURRENT r334649? Message-ID: <20180615090358.GB32922@pesky.lan> In-Reply-To: <20180615084808.GF4028@home.opsec.eu> References: <d3ee2b8f-bdbe-ce25-f496-6267f9bb0212@FreeBSD.org> <20180605181716.73b8ea91@ernst.home> <2925b27f-43cf-8813-eaa7-4f3d12bef8f0@FreeBSD.org> <20180605214808.GA94301@pesky> <20180615051025.GA79327@ns.kevlo.org> <20180615084022.GA32922@pesky.lan> <20180615084808.GF4028@home.opsec.eu>
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On Fri, Jun 15, 2018 at 10:48:08AM +0200, Kurt Jaeger wrote:
> Hi!
>
> > The change was committed as r334752. Are you seeing unexpected OOM
> > kills on or after that revision?
>
> When I tried to run a qemu-based poudriere run yesterday on a r334918
> box, it killed a few processes outside of that run and did not
> work out.
>
> I'm unsure it was because of that problem or a problem with qemu.
How much memory and swap does the guest have? Were you consistently
able to complete a run before?
If it's happening during a poudriere run, it may well have been a true
OOM situation. The patch below prints a few stats to the dmesg before
the kill. The output of that together with "sysctl vm" output should be
enough to determine what's happening.
diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c
index 264c98203c51..9c7ebcf451ec 100644
--- a/sys/vm/vm_pageout.c
+++ b/sys/vm/vm_pageout.c
@@ -1670,6 +1670,8 @@ vm_pageout_mightbe_oom(struct vm_domain *vmd, int page_shortage,
* start OOM. Initiate the selection and signaling of the
* victim.
*/
+ printf("v_free_count: %u, v_inactive_count: %u\n",
+ vmd->vmd_free_count, vmd->vmd_pagequeues[PQ_INACTIVE].pq_cnt);
vm_pageout_oom(VM_OOM_MEM);
/*
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