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a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1770044817; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Ytk8lPag9xgR3tZ3E4DGpPU73kiM6MeFw0yIXe1abZY=; b=fv6XBiHnqDSNdut5wZcjK+X2JhUdOjsr0IIZyGP+hFHCvMOoG/SjMnjKJV6QhSIRTzopBQ E1i18EBaNocbljLjg2Lv5nNRaQ265Zgvm4TJtF+Hf8CJ8jNvkoJkYCVl1WekWCDWjYnf3X c3zxx3pGJPvC9Q2i9QcrHDVYtg1qtko= X-MC-Unique: 9KzORM-AO0CzDddA_AnNoQ-1 X-Mimecast-MFC-AGG-ID: 9KzORM-AO0CzDddA_AnNoQ_1770044813 To: devel@lists.libvirt.org Subject: [PATCH 4/9] Expose latency histograms via 'virConnectGetAllDomainStats' Date: Mon, 2 Feb 2026 16:06:41 +0100 Message-ID: <51895450b434a08565fce95dfacdd03508cb53b5.1770044532.git.pkrempa@redhat.com> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: Q3whpHL3HyJsq3lriLqWzDUa6I2VCaZkspyG6nTWq9M_1770044813 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Message-ID-Hash: FWQLWJPWL5ATVXBSMANDJP4HQECNAS2U X-Message-ID-Hash: FWQLWJPWL5ATVXBSMANDJP4HQECNAS2U X-MailFrom: pkrempa@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; header-match-devel.lists.libvirt.org-0; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Development discussions about the libvirt library & tools Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: Peter Krempa via Devel Reply-To: Peter Krempa X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1770045150759154100 Content-Type: text/plain; charset="utf-8" From: Peter Krempa Add documentation and constants for constructing the stats field names for latency histograms and expose them in the qemu driver: Example: block.1.latency_histogram.read.bin.count=3D9 block.1.latency_histogram.read.bin.0.start=3D0 block.1.latency_histogram.read.bin.0.value=3D0 block.1.latency_histogram.read.bin.1.start=3D10 block.1.latency_histogram.read.bin.1.value=3D0 block.1.latency_histogram.read.bin.2.start=3D100 block.1.latency_histogram.read.bin.2.value=3D0 block.1.latency_histogram.read.bin.3.start=3D1000 block.1.latency_histogram.read.bin.3.value=3D1047 block.1.latency_histogram.read.bin.4.start=3D10000 block.1.latency_histogram.read.bin.4.value=3D2131 block.1.latency_histogram.read.bin.5.start=3D100000 block.1.latency_histogram.read.bin.5.value=3D0 block.1.latency_histogram.read.bin.6.start=3D1000000 block.1.latency_histogram.read.bin.6.value=3D0 block.1.latency_histogram.read.bin.7.start=3D10000000 block.1.latency_histogram.read.bin.7.value=3D0 block.1.latency_histogram.read.bin.8.start=3D100000000 block.1.latency_histogram.read.bin.8.value=3D0 Signed-off-by: Peter Krempa --- docs/manpages/virsh.rst | 7 ++ include/libvirt/libvirt-domain.h | 113 +++++++++++++++++++++++++++++++ src/qemu/qemu_driver.c | 43 ++++++++++++ 3 files changed, 163 insertions(+) diff --git a/docs/manpages/virsh.rst b/docs/manpages/virsh.rst index a9d691824e..ff0cf1a715 100644 --- a/docs/manpages/virsh.rst +++ b/docs/manpages/virsh.rst @@ -2811,6 +2811,13 @@ Information listed includes: pending write operations in the defined interval * ``block..timed_group..zone_append_queue_depth_avg`` - average = number of pending zone append operations in the defined interval +* ``block..latency_histogram..bin.count`` - number of bins in + latency histogram. is one of ``read``, ``write``, ``zone_append``= , or + ``flush`` +* ``block..latency_histogram..bin..start`` start boundary = of + a latency histogram bin in nanoseconds of given operation duration +* ``block..latency_histogram..bin..value`` current number = of + events corresponding to the given bin and type *--iothread* returns information about IOThreads on the running guest diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-dom= ain.h index 893359aaae..56c21dcf25 100644 --- a/include/libvirt/libvirt-domain.h +++ b/include/libvirt/libvirt-domain.h @@ -3896,6 +3896,119 @@ struct _virDomainStatsRecord { */ # define VIR_DOMAIN_STATS_BLOCK_SUFFIX_TIMED_GROUP_SUFFIX_ZONE_APPEND_QUEU= E_DEPTH_AVG ".zone_append_queue_depth_avg" +/** + * VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_READ_PREFIX: + * + * The parameter name prefix to access 'read' latency histograms. Concaten= ate + * the prefix with either: + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_COUNT + * to get the number of bins in given histogram + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_PREFIX and + * entry number formatted as an unsigned integer and one of the latency + * histogram suffix parameters to compelte a full bin parameter name + * + * Since: 12.1.0 + */ +# define VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_READ_PREFIX ".lat= ency_histogram.read." + +/** + * VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_WRITE_PREFIX: + * + * The parameter name prefix to access 'write' latency histograms. Concate= nate + * the prefix with either: + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_COUNT + * to get the number of bins in given histogram + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_PREFIX and + * entry number formatted as an unsigned integer and one of the latency + * histogram suffix parameters to compelte a full bin parameter name + * + * Since: 12.1.0 + */ +# define VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_WRITE_PREFIX ".la= tency_histogram.write." + +/** + * VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_ZONE_APPEND_PREFIX: + * + * The parameter name prefix to access 'zone_append' latency histograms. C= oncatenate + * the prefix with either: + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_COUNT + * to get the number of bins in given histogram + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_PREFIX and + * entry number formatted as an unsigned integer and one of the latency + * histogram suffix parameters to compelte a full bin parameter name + * + * Since: 12.1.0 + */ +# define VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_ZONE_APPEND_PREFI= X ".latency_histogram.zone_append." + +/** + * VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_FLUSH_PREFIX: + * + * The parameter name prefix to access 'flush' latency histograms. Concate= nate + * the prefix with either: + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_COUNT + * to get the number of bins in given histogram + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_PREFIX and + * entry number formatted as an unsigned integer and one of the latency + * histogram suffix parameters to compelte a full bin parameter name + * + * Since: 12.1.0 + */ +# define VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_FLUSH_PREFIX ".la= tency_histogram.flush." + +/** + * VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_COUNT: + * + * The parameter name suffix to access number of bins in one of the follow= ing + * latency histogram types: + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_READ_PREFIX + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_WRITE_PREFIX + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_ZONE_APPEND_PREFIX + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_FLUSH_PREFIX + * + * Number of bins in latency histogram as unsigned long long. + * + * Since: 12.1.0 + */ +# define VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_COUNT = "bin.count" + +/** + * VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_PREFIX: + * + * The parameter name suffix to access a latency histogram bin in one of t= he + * following latency histogram types: + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_READ_PREFIX + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_WRITE_PREFIX + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_ZONE_APPEND_PREFIX + * - VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_FLUSH_PREFIX + * + * Concatenate with a bin number as unsigned int and one of the other field + * suffixes to access bin parameters. + * + * Since: 12.1.0 + */ +# define VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_PREFIX= "bin." + +/** + * VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_SUFFIX_START: + * + * Start of the current latency histogram bin in nanoseconds as unsigned l= ong long. + * + * Since: 12.1.0 + */ +# define VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_SUFFIX= _START ".start" + +/** + * VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_SUFFIX_VALUE: + * + * Current value of the number of occurences of the latency within this bin + * as unsigned long long. + * + * Since: 12.1.0 + */ +# define VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_SUFFIX= _VALUE ".value" + + /** * VIR_DOMAIN_STATS_PERF_CMT: * diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index cdd333c882..d8cc32eee8 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -17606,6 +17606,36 @@ qemuDomainGetStatsBlockExportBackendStorage(const = char *entryname, } +static void +qemuDomainGetStatsBlockExportFrontendLatencyHistogram(struct qemuBlockStat= sLatencyHistogram *h, + size_t disk_idx, + const char *prefix_h= ist, + virTypedParamList *p= ar) +{ + size_t i; + + if (!h) + return; + + virTypedParamListAddULLong(par, h->nbins, + VIR_DOMAIN_STATS_BLOCK_PREFIX "%zu%s" VIR_D= OMAIN_STATS_BLOCK_SUFFIX_LATENCY_HISTOGRAM_SUFFIX_BIN_COUNT, + disk_idx, prefix_hist); + + for (i =3D 0; i < h->nbins; i++) { + virTypedParamListAddULLong(par, h->bins[i].start, + VIR_DOMAIN_STATS_BLOCK_PREFIX "%zu%s" + VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_H= ISTOGRAM_SUFFIX_BIN_PREFIX "%zu" + VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_H= ISTOGRAM_SUFFIX_BIN_SUFFIX_START, + disk_idx, prefix_hist, i); + virTypedParamListAddULLong(par, h->bins[i].value, + VIR_DOMAIN_STATS_BLOCK_PREFIX "%zu%s" + VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_H= ISTOGRAM_SUFFIX_BIN_PREFIX "%zu" + VIR_DOMAIN_STATS_BLOCK_SUFFIX_LATENCY_H= ISTOGRAM_SUFFIX_BIN_SUFFIX_VALUE, + disk_idx, prefix_hist, i); + } +} + + static void qemuDomainGetStatsBlockExportFrontend(const char *frontendname, GHashTable *stats, @@ -17730,6 +17760,19 @@ qemuDomainGetStatsBlockExportFrontend(const char *= frontendname, idx, i); } } + + qemuDomainGetStatsBlockExportFrontendLatencyHistogram(en->histogram_re= ad, idx, + VIR_DOMAIN_STATS= _BLOCK_SUFFIX_LATENCY_HISTOGRAM_READ_PREFIX, + par); + qemuDomainGetStatsBlockExportFrontendLatencyHistogram(en->histogram_wr= ite, idx, + VIR_DOMAIN_STATS= _BLOCK_SUFFIX_LATENCY_HISTOGRAM_WRITE_PREFIX, + par); + qemuDomainGetStatsBlockExportFrontendLatencyHistogram(en->histogram_zo= ne, idx, + VIR_DOMAIN_STATS= _BLOCK_SUFFIX_LATENCY_HISTOGRAM_ZONE_APPEND_PREFIX, + par); + qemuDomainGetStatsBlockExportFrontendLatencyHistogram(en->histogram_fl= ush, idx, + VIR_DOMAIN_STATS= _BLOCK_SUFFIX_LATENCY_HISTOGRAM_FLUSH_PREFIX, + par); } --=20 2.52.0