Control: tag -1 - moreinfo Control: severity -1 normal On Wed, 2018-06-13 at 07:01 -0500, Luigi P. Bai wrote: > Hi Ben, > > Thank you for looking at this report. > > You asked what is running on the machine. The first thing I want to > point out is that it's the same stack of processes that were running on > the 3.x version of the kernel; the kernel was the only upgrade. The > system is "mostly jessie" with "apt-get -t stretch install > linux-image-orion5x". > > This is a QNAP NAS, so it mostly runs a steady state of apache, nagios, > smb, cups, dnscache, mysql, postfix, slapd, and the other "regular" > daemons. In the middle of the night it'll catch an rsync request backing > up another machine on the network. These OOM reports seem to happen both > at night and during the "steady state" during the day when I'm at work > and away from the machines (this is happening on my other QNAP too).
This seems like quite a lot of services to run on a 256 MB system. > I seem to remember the (very rare) OOM reports I'd seen in the past also > listing the process name, number, and backtrace when the process was > killed. Has the OOM reporting changed? Has page allocation changed from > 3.x to 4.x to cause this? I'm not noticing that long running processes > are being killed, and I'm not seeing any other reports in the log files > of processes being killed. When handling received network packets, the kernel cannot wait for memory to be freed up (that's what the "GFP_ATOMIC" indicates), so it relies on the kernel memory manager keeping some memory free at all times. I think that the "OOM killer" will only be triggered by allocation requests that can wait to free up memory, but I'm not sure. This error was triggered by a request for 2 adjacent pages of memory, when there were only single pages of memory free. It's possible that the change in behaviour is due to a kernel structure growing to occupy 2 pages where it previously fit into 1. You might be able to reduce the likelihood of this error by increasing the vm.min_free_kbytes sysctl. Or by running fewer services. Ben. -- Ben Hutchings The most exhausting thing in life is being insincere. - Anne Morrow Lindberg
Description: This is a digitally signed message part