Re: [libvirt] [PATCH 2/2] qemu: Adaptive timeout for connecting to monitor

On 03/15/2017 02:16 AM, Jim Fehlig wrote: > On 03/13/2017 06:29 AM, Michal Privoznik wrote: >> There were couple of reports on the list (e.g. [1]) that guests >> with huge amounts of RAM are unable to start because libvirt >> kills qemu in the initialization phase. The problem is that if >> guest is configured to use hugepages kernel has to zero them all >> out before handing over to qemu process. For instance, 402GiB >> worth of 1GiB pages took around 105 seconds (~3.8GiB/s). Since we >> do not want to make the timeout for connecting to monitor >> configurable [2], we have to teach libvirt to count with this >> fact. This commit implements "1s per each 1GiB of RAM" approach >> as suggested here [3]. > FYI, on another machine I observed ~1.5 seconds for each 5G of memory. > >> 1: https://www.redhat.com/archives/libvir-list/2017-March/msg00373.html >> 3: https://www.redhat.com/archives/libvir-list/2017-March/msg00405.html >> >> 2: The reason is that ideally someday it will be Libvirt who >> creates the monitor socket and qemu will just use it. > This point isn't clear to me wrt the changes done by the commit. Okay, I can remove it. >> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; >> --- >> src/qemu/qemu_capabilities.c | 2 +- >> src/qemu/qemu_monitor.c | 36 +++++++++++++++++++++++++++++++----- >> src/qemu/qemu_monitor.h | 1 + >> src/qemu/qemu_process.c | 8 ++++++++ >> tests/qemumonitortestutils.c | 1 + >> 5 files changed, 42 insertions(+), 6 deletions(-) >> > Looks good. You can decide about the nits. ACK in principle, but I'm not > able to test this ATM. The host I was using is now running a VM that > uses most of its memory. Matt might be running a test in that VM so I > don't want to kill it :-). I can test the patches tomorrow and report > back if you want to wait a bit before pushing. Sure. I will wait for your report and thus full ACK.