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.
Reviewed-by: Andrew Jones <drjo...@redhat.com>
Signed-off-by: Yanan Wang <wangyana...@huawei.com>
---
hw/core/machine.c | 30 +++++++++++++++---------------
hw/i386/pc.c | 30 +++++++++++++++---------------
2 files changed, 30 insertions(+), 30 deletions(-)
diff --git a/hw/core/machine.c b/hw/core/machine.c
index 696d9e8e47..69979c93dd 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -755,24 +755,26 @@ static void smp_parse(MachineState *ms, SMPConfiguration
*config, Error **errp)
}
/* compute missing values, prefer sockets over cores over threads */
- if (cpus == 0 || sockets == 0) {
+ maxcpus = maxcpus > 0 ? maxcpus : cpus;
+
+ if (cpus == 0) {
+ sockets = sockets > 0 ? sockets : 1;
cores = cores > 0 ? cores : 1;
threads = threads > 0 ? threads : 1;
- if (cpus == 0) {
- sockets = sockets > 0 ? sockets : 1;
- cpus = cores * threads * sockets;
- } else {
- maxcpus = maxcpus > 0 ? maxcpus : cpus;
- sockets = maxcpus / (cores * threads);
- }
+ 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)",
@@ -780,8 +782,6 @@ 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;
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index acd31af452..a9ff9ef52c 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -725,24 +725,26 @@ 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) {
+ maxcpus = maxcpus > 0 ? maxcpus : cpus;
+
+ if (cpus == 0) {
+ sockets = sockets > 0 ? sockets : 1;
cores = cores > 0 ? cores : 1;
threads = threads > 0 ? threads : 1;
- if (cpus == 0) {
- sockets = sockets > 0 ? sockets : 1;
- cpus = cores * threads * dies * sockets;
- } else {
- maxcpus = maxcpus > 0 ? maxcpus : cpus;
- sockets = maxcpus / (dies * cores * threads);
- }
+ 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)",
@@ -750,8 +752,6 @@ 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;
--
2.19.1
