Re: [libvirt] [PATCH] Drop dependency on pm-is-supported

On 03/28/2014 10:32 AM, Cédric Bosdonnat wrote: > From: Cédric Bosdonnat <cedric.bosdonnat(a)free.fr&gt; > > pm-is-supported is the only thing needed in pm-utils, better get rid of > it since systemd is heavily used for libvirt. > --- > src/util/virnodesuspend.c | 34 ++++++++++++++++++++-------------- > 1 file changed, 20 insertions(+), 14 deletions(-) You also need to modify libvirt.spec.in to drop the dependency.

> > > + if (virFileReadAll("/sys/power/state", 1024, &buf) < 0) > + goto cleanup; > + > + states = virStringSplit(buf, " ", 0); > + > + canSuspend = (virStringArrayHasString(states, "mem") || > + virStringArrayHasString(states, "standby")); > + canHibernate = virStringArrayHasString(states, "disk"); pm-is-supported checks a bit more than what your replacement checks. For suspend, it declares yes if any of these succeed: grep -q mem /sys/power/state [ -c /dev/pmu ] && pm-pmu --check grep -q standby /sys/power/state

For hibernate, it requires that BOTH of these succeed: [ -f /sys/power/disk ] grep -q disk /sys/power/state

For hybrid, it requires that all three succeed: [ -f /sys/power/disk ] && \ grep -q disk /sys/power/state && \ grep -q suspend /sys/power/disk

as well as having fallback code to fake a hybrid sleep by joining the other two states. > + > switch (target) { > case VIR_NODE_SUSPEND_TARGET_MEM: > - cmd = virCommandNewArgList("pm-is-supported", "--suspend", NULL); > + *supported = canSuspend; > break; > case VIR_NODE_SUSPEND_TARGET_DISK: > - cmd = virCommandNewArgList("pm-is-supported", "--hibernate", NULL); > + *supported = canHibernate; > break; > case VIR_NODE_SUSPEND_TARGET_HYBRID: > - cmd = virCommandNewArgList("pm-is-supported", "--suspend-hybrid", NULL); > + *supported = canSuspend && canHibernate; I'm not sure if your simpler checks will cause us to declare an action unsupported on systems where it was previously declared supported by pm-is-supported. I think the idea makes sense, but I'd like a second opinion that we aren't hurting ourselves by doing fewer checks than what we are replacing.