Date: Fri, 6 Apr 2018 10:25:06 -0500 From: Justin Hibbits <chmeeedalf@gmail.com> To: Mark Johnston <markj@freebsd.org> Cc: Jeff Roberson <jroberson@jroberson.net>, FreeBSD current <freebsd-current@freebsd.org> Subject: Re: Strange ARC/Swap/CPU on yesterday's -CURRENT Message-ID: <CAHSQbTCGmw5-_b1VJn6iotYovfDdPZ6RDC1pT9%2B9J=7%2BGzD=%2Bg@mail.gmail.com> In-Reply-To: <20180406150814.GB10017@raichu> References: <alpine.BSF.2.21.1803111038460.1232@desktop> <20180320070745.GA12880@server.rulingia.com> <2b3db2af-03c7-65ff-25e7-425cfd8815b6@FreeBSD.org> <1fd2b47b-b559-69f8-7e39-665f0f599c8f@FreeBSD.org> <tkrat.9bab32187c0e8d01@FreeBSD.org> <tkrat.11e402b8455bd0fa@FreeBSD.org> <tkrat.7e60fe1978ea51c0@FreeBSD.org> <20180404174949.GA12271@raichu> <tkrat.5960d3aa016999f6@FreeBSD.org> <CAHSQbTBjs=5Nq-QGZftYh8rDwMuCZN7CrsLt0OPPOyzW2V6_Ow@mail.gmail.com> <20180406150814.GB10017@raichu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, Apr 6, 2018 at 10:08 AM, Mark Johnston <markj@freebsd.org> wrote: > On Fri, Apr 06, 2018 at 12:47:14AM +0000, Justin Hibbits wrote: >> My powerpc64 embedded machine is virtually unusable since these vm changes. >> I tried setting vfs.zfs.arc_free_target as suggested, and that didn't help >> at all. Eventually the machine hangs and just gets stuck in vmdaemon, with >> many processes in wait channel btalloc. > > You don't really have the same symptoms that Don is reporting. Okay. I latched onto the thread because it seemed similar. > Threads being stuck in btalloc implies a KVA shortage. So: > - What do you mean by "stuck in vmdaemon"? The machine hangs, and my ssh sessions get killed. I can't do anything at the console except break into kdb. When I do, the running thread is always vmdaemon. > - Which commits specifically cause problems? Does reverting r329882 fix the > hang? I'll try reverting it and report back. Thankfully I can buildkernel successfully on the machine before it hangs. Can't do more than that, though. > - Can you break to DDB and get "show page" output when the hang occurs? I'll reproduce and get numbers today, but I do know the free_count was high (6 digits), much higher than the free_min. when I checked yesterday. I'm surprised it's running out of KVA, I've never had the problem before with the same workloads, and has ~7.5GB KVA (almost the same size as the total RAM in the machine). > - What is the system doing to cause the hang to occur? Just a simple buildworld with 2 or 3 jobs (tried both). It's 100% reproducible. - Justin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAHSQbTCGmw5-_b1VJn6iotYovfDdPZ6RDC1pT9%2B9J=7%2BGzD=%2Bg>