Date: Thu, 30 Jul 2015 01:39:12 -0700 From: Doug Hardie <bc979@lafn.org> To: Peter Jeremy <peter@rulingia.com> Cc: FreeBSD Stable ML <stable@freebsd.org> Subject: Re: Swap Usage Message-ID: <10F94D23-E58C-466E-ADCA-5E6670054BD7@lafn.org> In-Reply-To: <20150730064444.GA88137@server.rulingia.com> References: <BCA67F7E-676A-4226-83A0-84229948895E@lafn.org> <20150730064444.GA88137@server.rulingia.com>
next in thread | previous in thread | raw e-mail | index | archive | help
> On 29 July 2015, at 23:44, Peter Jeremy <peter@rulingia.com> wrote: >=20 > [reformatted] >=20 > On 2015-Jul-29 17:41:33 -0700, Doug Hardie <bc979@lafn.org> wrote: >> I have several FreeBSD 9.3 systems that are using swap and I can=E2=80=99= t >> figure out what is doing it. The key system has 6GB swap and >> currently it has over 2GB in use. >=20 > Is the system currently paging (top(1) and "systat -v" will show > this)? If not, this just means that at some time in the past, the > system was under memory pressure and paged some process memory out. > Since then, that memory hasn't been touched so the system hasn't paged > it in. >=20 >> ps shows only a kernel module >> [intr] with a W status. >=20 > 'W' means the whole process is 'swapped' out - this will only occur > under severe RAM pressure. Normally, the system will just page out > inactive parts of a processes address space - and none of the ps flags > will show this. >=20 >> How do I figure out what that swap space is being used for? >=20 > I don't think this can be trivially done. "procstat -v" will show > the number of resident pages within each swap-backed region, any > pages in that region that have been touched but are not resident > are on the swap device but any pages that have never been touched > aren't counted at all. Bingo. procstat shows the problem. The process that I suspected has a = large number of entries like: 650 0x834c00000 0x835800000 rw- 0 0 1 0 ---- = sw=20 650 0x835800000 0x835c00000 rw- 0 0 1 0 ---- = sw=20 650 0x835c00000 0x837c00000 rw- 1 0 1 0 ---- = sw=20 I don=E2=80=99t know whats in those areas yet. If I were to kill the = process with SIGABRT would the core dump show those areas? I might be = able to figure out what they are from that. Thanks for the pointer.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?10F94D23-E58C-466E-ADCA-5E6670054BD7>