On Fri, Aug 6, 2021 at 2:44 PM Rosemarie O'Riorden <rorio...@redhat.com> wrote: > > If anonymous memory mapping is supported by the kernel, it's better > to run OVS entirely in memory rather than creating shared data > structures. OVS doesn't work in multi-process mode, so there is no need > to litter a filesystem and experience random crashes due to old memory > chunks stored in re-opened files. > > When OVS is not running in memory and crashes, it never reaches the > clean up scripts that delete the new files it has created, resulting in > "dirty" memory. OVS will partially overwrite this memory on the next > start-up, but will fail to run again because its filesystem is full of > old memory. > > Here is an example of these crashes: > https://inbox.dpdk.org/dev/20200910162407.12669-1-david.march...@redhat.com/
Overall, I am fine with this change. - In the commitlog, I would focus on the simplication aspect and that we only use what we need. Mention of this bug can be removed. The reason is that this is not as black/white as described: reusing dirty memory only happened in a special case with containers. But this does not affect OVS (I don't think we run OVS in containers). - As mentionned by Ilya, MAP_HUGE_SHIFT is most likely supported on systems running current OVS. Can we remove the permissions tweak on /dev/hugepages in rhel/usr_lib_systemd_system_ovs-vswitchd.service.in ? (Cc: Timothy who might have an opinion on this). - Somehow related: * as a followup, we can deprecate --dpdk-hugepage-dir, * I have been playing with --in-memory and I noticed some bug with the telemetry socket. The last started dpdk process takes control of the socket regardless of other processes, so this happens when running multiple dpdk applications with none or same XDG_RUNTIME_DIR set in env. This is more of a fyi: it should not be a problem for people running ovs with a dedicated user, but it could be a problem for those vilains that run all their applications as root (/me whistles). > > Reported at: https://bugzilla.redhat.com/show_bug.cgi?id=1949849 > Signed-off-by: Rosemarie O'Riorden <rorio...@redhat.com> Thanks, -- David Marchand _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
