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[PATCH for-6.2 v2 03/11] machine: Uniformly use maxcpus to calculate the
From: |
Yanan Wang |
Subject: |
[PATCH for-6.2 v2 03/11] machine: Uniformly use maxcpus to calculate the omitted parameters |
Date: |
Mon, 19 Jul 2021 11:20:35 +0800 |
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 invalid cpu topology check.
Since we require for the valid config that the sum of "sockets * cores
* dies * 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 splited into two
branches of "cpus == 0" and "sockets == 0" so that we can clearly read
that we are parsing -smp cmdlines with a preference of cpus over sockets
over cores over threads.
Note: change in this patch won't affect any existing working cmdlines
but improves consistency and allow more incomplete configs to be valid.
Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
---
hw/core/machine.c | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/hw/core/machine.c b/hw/core/machine.c
index ed6712e964..c9f15b15a5 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -768,24 +768,26 @@ 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 = sockets * dies * cores * threads;
- } 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 / (sockets * dies * cores);
- threads = threads > 0 ? threads : 1;
- } else if (sockets * dies * cores * threads < cpus) {
+ threads = maxcpus / (sockets * dies * cores);
+ }
+
+ if (sockets * dies * cores * threads < cpus) {
g_autofree char *dies_msg = g_strdup_printf(
mc->smp_dies_supported ? " * dies (%u)" : "", dies);
error_setg(errp, "cpu topology: "
@@ -795,8 +797,6 @@ 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;
--
2.19.1