Re: wired memory leak at r298785

From: Trond Endrestøl <Trond.Endrestol_at_fagskolen.gjovik.no>
Date: Tue, 3 May 2016 20:20:46 +0200 (CEST)
On Tue, 3 May 2016 08:27-0600, Scott Long wrote:

> 
> > On May 3, 2016, at 12:20 AM, Mark Johnston <markj_at_FreeBSD.org> wrote:
> > 
> > On Mon, May 02, 2016 at 08:55:58PM -0400, Steve Wills wrote:
> >> Hi,
> >> 
> >> On 05/ 2/16 09:32 AM, Steve Wills wrote:
> >>> Hi,
> >>> 
> >>> Just did my monthly update and r298785 seems to be leaking wired memory
> >>> rather rapidly. My system has 8gb of RAM and the amount of wired memory
> >>> just goes up and up continuously. It takes about 12 hours before it
> >>> exhausts all the RAM and sort of locks up (though shutdown still works).
> >>> 
> >>> I also made one other change to the system at the same time as updating,
> >>> which was to add another disk and configure it using ZFS. Perhaps this
> >>> is a ZFS on PowerPC64 issue? My amd64 box running the same rev of
> >>> CURRENT doesn't have the issue.
> >>> 
> >> 
> >> I've rebooted the box and started repeatedly logging the output of
> >> vmstat -m. It seems to show CAM CCB using a lot of memory and growing
> >> rather rapidly. For example, here's a few lines of diff output:
> >> 
> >> - CAM CCB 91418 182836K - 187149 2048
> >> + CAM CCB 447070 894140K - 900292 2048
> >> 
> >> from two samples that are 60 minutes apart.
> >> 
> >> The box is isn't terribly busy, it's just running the monitoring daemons
> >> running (snmpd, collectd), whatever web requests are hitting it (very
> >> few if any), this logging process, and my shell, etc.
> > 
> > This was causing problems on one of my amd64 systems, so it's not
> > specific to powerpc64. It turns out to be due to r298004: the CCB
> > allocated in cam_periph_devctl_notify() never gets freed. The patch
> > below seems to fix it.
> 
> Thanks Mark, that looks like the right fix.  I’ll put it in today.
> 
> Scott

A few of my stable/10 systems simple froze due to this bug. Would it 
be possible for the kernel to detect when it's running low on (kernel) 
memory, or when it's completely out of (kernel) memory, and call on 
panic() only to limp away for a day or so before rebooting again?

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Received on Tue May 03 2016 - 16:20:53 UTC

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