machine: Uniformly use maxcpus to calculate the omitted parameters

We are currently using maxcpus to calculate the omitted sockets
but using cpus to calculate the omitted cores/threads. This makes
cmdlines like:
  -smp cpus=8,maxcpus=16
  -smp cpus=8,cores=4,maxcpus=16
  -smp cpus=8,threads=2,maxcpus=16
work fine but the ones like:
  -smp cpus=8,sockets=2,maxcpus=16
  -smp cpus=8,sockets=2,cores=4,maxcpus=16
  -smp cpus=8,sockets=2,threads=2,maxcpus=16
break the sanity check.

Since we require for a valid config that the product of "sockets * cores
* threads" should equal to the maxcpus, we should uniformly use maxcpus
to calculate their omitted values.

Also the if-branch of "cpus == 0 || sockets == 0" was split into two
branches of "cpus == 0" and "sockets == 0" so that we can clearly read
that we are parsing the configuration with a preference on cpus over
sockets over cores over threads.

Note: change in this patch won't affect any existing working cmdlines
but improves consistency and allows more incomplete configs to be valid.

Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210929025816.21076-5-wangyanan55@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Yanan Wang 2021-09-29 10:58:04 +08:00 committed by Paolo Bonzini
parent 5d8b5a5055
commit 9a52b50806
2 changed files with 30 additions and 30 deletions

View File

@ -760,24 +760,26 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
}
/* compute missing values, prefer sockets over cores over threads */
if (cpus == 0 || sockets == 0) {
cores = cores > 0 ? cores : 1;
threads = threads > 0 ? threads : 1;
maxcpus = maxcpus > 0 ? maxcpus : cpus;
if (cpus == 0) {
sockets = sockets > 0 ? sockets : 1;
cpus = cores * threads * sockets;
} else {
cores = cores > 0 ? cores : 1;
threads = threads > 0 ? threads : 1;
cpus = sockets * cores * threads;
maxcpus = maxcpus > 0 ? maxcpus : cpus;
} else if (sockets == 0) {
cores = cores > 0 ? cores : 1;
threads = threads > 0 ? threads : 1;
sockets = maxcpus / (cores * threads);
}
} else if (cores == 0) {
threads = threads > 0 ? threads : 1;
cores = cpus / (sockets * threads);
cores = cores > 0 ? cores : 1;
cores = maxcpus / (sockets * threads);
} else if (threads == 0) {
threads = cpus / (cores * sockets);
threads = threads > 0 ? threads : 1;
} else if (sockets * cores * threads < cpus) {
threads = maxcpus / (sockets * cores);
}
if (sockets * cores * threads < cpus) {
error_setg(errp, "cpu topology: "
"sockets (%u) * cores (%u) * threads (%u) < "
"smp_cpus (%u)",
@ -785,8 +787,6 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
return;
}
maxcpus = maxcpus > 0 ? maxcpus : cpus;
if (maxcpus < cpus) {
error_setg(errp, "maxcpus must be equal to or greater than smp");
return;

View File

@ -727,24 +727,26 @@ static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **err
dies = dies > 0 ? dies : 1;
/* compute missing values, prefer sockets over cores over threads */
if (cpus == 0 || sockets == 0) {
cores = cores > 0 ? cores : 1;
threads = threads > 0 ? threads : 1;
maxcpus = maxcpus > 0 ? maxcpus : cpus;
if (cpus == 0) {
sockets = sockets > 0 ? sockets : 1;
cpus = cores * threads * dies * sockets;
} else {
cores = cores > 0 ? cores : 1;
threads = threads > 0 ? threads : 1;
cpus = sockets * dies * cores * threads;
maxcpus = maxcpus > 0 ? maxcpus : cpus;
} else if (sockets == 0) {
cores = cores > 0 ? cores : 1;
threads = threads > 0 ? threads : 1;
sockets = maxcpus / (dies * cores * threads);
}
} else if (cores == 0) {
threads = threads > 0 ? threads : 1;
cores = cpus / (sockets * dies * threads);
cores = cores > 0 ? cores : 1;
cores = maxcpus / (sockets * dies * threads);
} else if (threads == 0) {
threads = cpus / (cores * dies * sockets);
threads = threads > 0 ? threads : 1;
} else if (sockets * dies * cores * threads < cpus) {
threads = maxcpus / (sockets * dies * cores);
}
if (sockets * dies * cores * threads < cpus) {
error_setg(errp, "cpu topology: "
"sockets (%u) * dies (%u) * cores (%u) * threads (%u) < "
"smp_cpus (%u)",
@ -752,8 +754,6 @@ static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **err
return;
}
maxcpus = maxcpus > 0 ? maxcpus : cpus;
if (maxcpus < cpus) {
error_setg(errp, "maxcpus must be equal to or greater than smp");
return;