Date: Tue, 22 Sep 2020 19:31:07 +0200 From: Peter <pmc@citylink.dinoex.sub.org> To: Mark Johnston <markj@freebsd.org> Cc: freebsd-stable@freebsd.org Subject: Re: How to free used Swap-Space? Message-ID: <20200922173107.GA27670@gate.oper.dinoex.org> In-Reply-To: <20200922163319.GA70673@raichu> References: <20200922160801.GA19535@gate.oper.dinoex.org> <20200922163319.GA70673@raichu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, Sep 22, 2020 at 12:33:19PM -0400, Mark Johnston wrote:
! On Tue, Sep 22, 2020 at 06:08:01PM +0200, Peter wrote:
! > my machine should use about 3-4, maybe 5 GB swapspace. Today I found
! > it suddenly uses 8 GB (which is worryingly near the configured 10G).
! >
! > I stopped all the big suckers - nothing found.
! > I stopped all the jails - no success.
! > I brought it down to singleuser: it tried to swapoff, but failed.
! >
! > I unmounted all filesystems, exported all pools, detached all geli,
! > and removed most of the netgraphs. Swap is still occupied.
! > ! > Machine is now running only the init and a shell processes, has
! > almost no filesystems mounted, has mostly native networks only, and
! > this still occupies 3 GB of swap which cannot be released.
! >
! > What is going on, what is doing this, and how can I get this swapspace
! > released??
!
! Do you have any shared memory segments lingering? ipcs -a will show
! SysV shared memory usage.
I have four small shmem segments from four postgres clusters running.
These should cleanly disappear when the clusters are stopped, and
they are very small.
Shared Memory:
T ID KEY MODE OWNER GROUP CREATOR CGROUP NATTCH SEGSZ CPID LPID ATIME DTIME CTIME
m 65536 5432001 --rw------- postgres postgres postgres postgres 7 48 4793 4793 6:09:34 18:00:31 6:09:34
m 65537 0 --rw------- postgres postgres postgres postgres 11 48 6268 6268 6:09:42 10:48:27 6:09:42
m 65538 0 --rw------- postgres postgres postgres postgres 5 48 6968 6968 6:09:46 18:28:36 6:09:46
m 65539 0 --rw------- postgres postgres postgres postgres 6 48 6992 6992 6:09:47 3:38:34 6:09:47
! For POSIX shared memory, in 11.4 we do not
! have any good way of listing objects, but "vmstat -m | grep shmfd" will
! at least show whether any are allocated.
There is something, and I don't know who owns that:
$ vmstat -m | grep shmfd
shmfd 13 14K - 473 64,256,1024,8192
But that doesn't look big either.
Furthermore, this machine is running for quite some time already; it
was running as i386 (with ZFS) until very recently, and I know quite
well what is using much memory: these 3 GB were illegitimate; they
came from nothing I did install. And they are new; this has not
happened before.
! If those don't turn anything
! up then it's possible that there's a swap leak. Do you use any DRM
! graphics drivers on this system?
Probably yes. There is no graphics used at all; it just uses "device
vt" in text mode, but it uses i5-3570T CPU (IvyBridge HD2500) graphics
for that, and the driver is "drm2" and "i915drm" from /usr/src/sys (not
those from ports).
Not sure how that would account for 3 GB, unless there is indeed some
leak.
regards,
PMc
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20200922173107.GA27670>