8:25 a.m.
Add an element to configure the thread pool size:
...
<binary>
<thread_pool size='16'/>
</binary>
...
https://bugzilla.redhat.com/show_bug.cgi?id=2072905
Signed-off-by: Ján Tomko <jtomko(a)redhat.com>
---
docs/formatdomain.rst | 6 ++++++
src/conf/domain_conf.c | 14 ++++++++++++++
src/conf/domain_conf.h | 1 +
src/conf/schemas/domaincommon.rng | 9 +++++++++
tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml | 1 +
5 files changed, 31 insertions(+)
diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index 7da625380c..e8bff7632a 100644
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -3329,6 +3329,7 @@ A directory on the host that can be accessed directly from the
guest.
<cache mode='always'/>
<sandbox mode='namespace'/>
<lock posix='on' flock='on'/>
+ <thread_pool size='16'/>
</binary>
<source dir='/path'/>
<target dir='mount_tag'/>
@@ -3462,6 +3463,11 @@ A directory on the host that can be accessed directly from the
guest.
``chroot``, see the
`virtiofsd documentation
<https://qemu.readthedocs.io/en/latest/tools/virtiofsd.html>`__
for more details. ( :since:`Since 7.2.0` )
+ Element ``thread_pool`` accepts one attribute ``size`` which defines the
+ maximum thread pool size. A value of "0" disables the pool.
+ The thread pool helps increase the number of requests in flight when used with
+ storage that has a higher latency. However, it has an overhead, and so for
+ fast, low latency filesystems, it may be best to turn it off. ( :since:`Since 8.5.0`
)
``source``
The resource on the host that is being accessed in the guest. The ``name``
attribute must be used with ``type='template'``, and the ``dir`` attribute
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 761c3f4d87..05fac7b39c 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -2476,6 +2476,8 @@ virDomainFSDefNew(virDomainXMLOption *xmlopt)
ret->src = virStorageSourceNew();
+ ret->thread_pool_size = -1;
+
if (xmlopt &&
xmlopt->privateData.fsNew &&
!(ret->privateData = xmlopt->privateData.fsNew()))
@@ -9914,6 +9916,7 @@ virDomainFSDefParseXML(virDomainXMLOption *xmlopt,
if (def->fsdriver == VIR_DOMAIN_FS_DRIVER_TYPE_VIRTIOFS) {
g_autofree char *queue_size = virXPathString("string(./driver/@queue)",
ctxt);
g_autofree char *binary = virXPathString("string(./binary/@path)",
ctxt);
+ g_autofree char *thread_pool_size =
virXPathString("string(./binary/thread_pool/@size)", ctxt);
xmlNodePtr binary_node = virXPathNode("./binary", ctxt);
xmlNodePtr binary_lock_node = virXPathNode("./binary/lock", ctxt);
xmlNodePtr binary_cache_node = virXPathNode("./binary/cache", ctxt);
@@ -9926,6 +9929,13 @@ virDomainFSDefParseXML(virDomainXMLOption *xmlopt,
goto error;
}
+ if (thread_pool_size && virStrToLong_i(thread_pool_size, NULL, 10,
&def->thread_pool_size) < 0) {
+ virReportError(VIR_ERR_XML_ERROR,
+ _("cannot parse thread pool size '%s' for
virtiofs"),
+ queue_size);
+ goto error;
+ }
+
if (binary)
def->binary = virFileSanitizePath(binary);
@@ -24211,6 +24221,10 @@ virDomainFSDefFormat(virBuffer *buf,
}
virXMLFormatElement(&binaryBuf, "lock", &lockAttrBuf, NULL);
+
+ if (def->thread_pool_size >= 0)
+ virBufferAsprintf(&binaryBuf, "<thread_pool
size='%i'/>\n", def->thread_pool_size);
+
}
virDomainVirtioOptionsFormat(&driverAttrBuf, def->virtio);
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index da9e281214..8e0ccff543 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -906,6 +906,7 @@ struct _virDomainFSDef {
virTristateSwitch posix_lock;
virTristateSwitch flock;
virDomainFSSandboxMode sandbox;
+ int thread_pool_size;
virDomainVirtioOptions *virtio;
virObject *privateData;
};
diff --git a/src/conf/schemas/domaincommon.rng b/src/conf/schemas/domaincommon.rng
index efd49cfa01..ddbd9fa07d 100644
--- a/src/conf/schemas/domaincommon.rng
+++ b/src/conf/schemas/domaincommon.rng
@@ -3130,6 +3130,15 @@
</optional>
</element>
</optional>
+ <optional>
+ <element name="thread_pool">
+ <optional>
+ <attribute name="size">
+ <data type="integer"/>
+ </attribute>
+ </optional>
+ </element>
+ </optional>
</interleave>
</element>
</define>
diff --git a/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml
b/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml
index abddf0870b..81de8c0dd7 100644
--- a/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml
+++ b/tests/qemuxml2argvdata/vhost-user-fs-fd-memory.xml
@@ -32,6 +32,7 @@
<cache mode='always'/>
<sandbox mode='chroot'/>
<lock posix='off' flock='off'/>
+ <thread_pool size='16'/>
</binary>
<source dir='/path'/>
<target dir='mount_tag'/>
--
2.35.1