From: Yanan Wang <wangyanan55@huawei.com>
To: Eduardo Habkost <ehabkost@redhat.com>,
Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,
<qemu-devel@nongnu.org>, <qemu-arm@nongnu.org>,
<qemu-ppc@nongnu.org>, <qemu-s390x@nongnu.org>
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
"Andrew Jones" <drjones@redhat.com>,
"Cornelia Huck" <cohuck@redhat.com>,
"Daniel P . Berrangé" <berrange@redhat.com>,
"Pierre Morel" <pmorel@linux.ibm.com>,
"Michael S . Tsirkin" <mst@redhat.com>,
"Pankaj Gupta" <pankaj.gupta.linux@gmail.com>,
"Greg Kurz" <groug@kaod.org>,
"Yanan Wang" <wangyanan55@huawei.com>,
wanghaibin.wang@huawei.com, "Thomas Huth" <thuth@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"David Gibson" <david@gibson.dropbear.id.au>
Subject: [PATCH v8 03/14] machine: Uniformly use maxcpus to calculate the omitted parameters
Date: Thu, 2 Sep 2021 19:03:19 +0800 [thread overview]
Message-ID: <20210902110330.18036-4-wangyanan55@huawei.com> (raw)
In-Reply-To: <20210902110330.18036-1-wangyanan55@huawei.com>
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>
---
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 cf9cf53911..56bd3033a5 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -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) {
+ 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)",
@@ -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;
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 8733c2882f..4b67c49f38 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -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) {
+ 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)",
@@ -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;
--
2.19.1
next prev parent reply other threads:[~2021-09-02 11:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-02 11:03 [PATCH v8 00/14] machine: smp parsing fixes and improvement Yanan Wang
2021-09-02 11:03 ` [PATCH v8 01/14] machine: Deprecate "parameter=0" SMP configurations Yanan Wang
2021-09-02 11:03 ` [PATCH v8 02/14] machine: Minor refactor/fix for the smp parsers Yanan Wang
2021-09-02 11:03 ` Yanan Wang [this message]
2021-09-02 11:03 ` [PATCH v8 04/14] machine: Set the value of cpus to match maxcpus if it's omitted Yanan Wang
2021-09-02 11:03 ` [PATCH v8 05/14] machine: Improve the error reporting of smp parsing Yanan Wang
2021-09-02 11:03 ` [PATCH v8 06/14] machine: Prefer cores over sockets in smp parsing since 6.2 Yanan Wang
2021-09-02 11:03 ` [PATCH v8 07/14] machine: Use ms instead of global current_machine in sanity-check Yanan Wang
2021-09-02 11:03 ` [PATCH v8 08/14] machine: Tweak the order of topology members in struct CpuTopology Yanan Wang
2021-09-02 11:03 ` [PATCH v8 09/14] machine: Make smp_parse generic enough for all arches Yanan Wang
2021-09-02 11:03 ` [PATCH v8 10/14] machine: Remove smp_parse callback from MachineClass Yanan Wang
2021-09-02 11:03 ` [PATCH v8 11/14] machine: Move smp_prefer_sockets to struct SMPCompatProps Yanan Wang
2021-09-02 11:03 ` [PATCH v8 12/14] machine: Put all sanity-check in the generic SMP parser Yanan Wang
2021-09-02 11:03 ` [PATCH v8 13/14] machine: Split out the smp parsing code Yanan Wang
2021-09-02 11:03 ` [PATCH v8 14/14] tests/unit: Add a unit test for smp parsing Yanan Wang
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