Re: [PATCH] qemu: virtiofs: Add pool element to limit thread pool

From: Masayoshi Mizuma <m.mizuma(a)jp.fujitsu.com&gt; virtiofsd has --thread-pool-size=NUM option to limit the thread pool size. It will be useful to tune the performance. Add pool element to use the option like as: <filesystem type='mount' accessmode='passthrough'> <driver type='virtiofs' queue='1024'/> <binary path='/usr/libexec/virtiofsd' xattr='on' pool='32'/> <source dir='/path'/> <target dir='mount_tag'/> </filesystem> Signed-off-by: Masayoshi Mizuma <m.mizuma(a)jp.fujitsu.com&gt; ---

docs/formatdomain.rst | 6 ++++-- docs/schemas/domaincommon.rng | 5 +++++ src/conf/domain_conf.c | 12 ++++++++++++ src/conf/domain_conf.h | 1 + src/qemu/qemu_virtiofs.c | 3 +++ 5 files changed, 25 insertions(+), 2 deletions(-) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index bfa80e4bc2..0f66af5dc3 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -3070,7 +3070,7 @@ A directory on the host that can be accessed directly from the guest. </filesystem> <filesystem type='mount' accessmode='passthrough'> <driver type='virtiofs' queue='1024'/> - <binary path='/usr/libexec/virtiofsd' xattr='on'> + <binary path='/usr/libexec/virtiofsd' xattr='on' pool='32'> <cache mode='always'/> <lock posix='on' flock='on'/> </binary> @@ -3188,7 +3188,9 @@ A directory on the host that can be accessed directly from the guest. the use of filesystem extended attributes. Caching can be tuned via the ``cache`` element, possible ``mode`` values being ``none`` and ``always``. Locking can be controlled via the ``lock`` element - attributes ``posix`` and - ``flock`` both accepting values ``on`` or ``off``. ( :since:`Since 6.2.0` ) + ``flock`` both accepting values ``on`` or ``off``. ( :since:`Since 6.2.0` ). + Thread pool size limit can be tuned via the ``pool`` element. + ( :since:`Since 6.9.0` ) ``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/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index c25a742581..cd5de2ba80 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -2839,6 +2839,11 @@ <ref name="virOnOff"/> </attribute> </optional> + <optional> + <attribute name="pool"> + <ref name="unsignedInt"/> + </attribute> + </optional> <optional> <element name="cache"> <optional> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index efa5ac527b..9d06f8c75f 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -11588,6 +11588,7 @@ virDomainFSDefParseXML(virDomainXMLOptionPtr xmlopt, g_autofree char *cache = virXPathString("string(./binary/cache/@mode)", ctxt); g_autofree char *posix_lock = virXPathString("string(./binary/lock/@posix)", ctxt); g_autofree char *flock = virXPathString("string(./binary/lock/@flock)", ctxt); + g_autofree char *thread_pool_size = virXPathString("string(./binary/@pool)", ctxt); int val; if (queue_size && virStrToLong_ull(queue_size, NULL, 10, &def->queue_size) < 0) { @@ -11597,6 +11598,14 @@ virDomainFSDefParseXML(virDomainXMLOptionPtr xmlopt, goto error; } + if (thread_pool_size && + virStrToLong_ull(thread_pool_size, NULL, 10, &def->thread_pool_size) < 0) { + virReportError(VIR_ERR_XML_ERROR, + _("cannot parse thread pool size '%s' for virtiofs"), + thread_pool_size); + goto error; + } + if (binary) def->binary = virFileSanitizePath(binary); @@ -26191,6 +26200,9 @@ virDomainFSDefFormat(virBufferPtr buf, virTristateSwitchTypeToString(def->xattr)); } + if (def->thread_pool_size) + virBufferAsprintf(&binaryAttrBuf, " pool='%llu'", def->thread_pool_size); + if (def->cache != VIR_DOMAIN_FS_CACHE_MODE_DEFAULT) { virBufferAsprintf(&binaryBuf, "<cache mode='%s'/>\n", virDomainFSCacheModeTypeToString(def->cache)); diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index cd344716a3..98ab0a51c7 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -860,6 +860,7 @@ struct _virDomainFSDef { bool symlinksResolved; char *binary; unsigned long long queue_size; + unsigned long long thread_pool_size; virTristateSwitch xattr; virDomainFSCacheMode cache; virTristateSwitch posix_lock; diff --git a/src/qemu/qemu_virtiofs.c b/src/qemu/qemu_virtiofs.c index 2e239cad66..e35c278a1b 100644 --- a/src/qemu/qemu_virtiofs.c +++ b/src/qemu/qemu_virtiofs.c @@ -126,6 +126,9 @@ qemuVirtioFSBuildCommandLine(virQEMUDriverConfigPtr cfg, virCommandPassFD(cmd, *fd, VIR_COMMAND_PASS_FD_CLOSE_PARENT); *fd = -1; + if (fs->thread_pool_size) + virCommandAddArgFormat(cmd, "--thread-pool-size=%llu", fs->thread_pool_size); + virCommandAddArg(cmd, "-o"); virBufferAddLit(&opts, "source="); virQEMUBuildBufferEscapeComma(&opts, fs->src->path);