[libvirt] [PATCHv4 3/4] blkiotune: add interface for blkiotune.device_weight
Hu Tao
hutao at cn.fujitsu.com
Tue Nov 15 07:15:38 UTC 2011
On Mon, Nov 14, 2011 at 09:30:01PM -0700, Eric Blake wrote:
> From: Hu Tao <hutao at cn.fujitsu.com>
>
> This adds per-device weights to <blkiotune>. Note that the
> cgroups implementation only supports weights per block device,
> and not per-file within the device; hence this option must be
> global to the domain definition rather than tied to individual
> <devices>/<disk> entries:
>
> <domain ...>
> <blkiotune>
> <device>
> <path>/path/to/block</path>
> <weight>1000</weight>
> </device>
> </blkiotune>
> ..
>
> This patch also adds a parameter --device-weights to virsh command
> blkiotune for setting/getting blkiotune.weight_device for any
> hypervisor that supports it. All <device> entries under
> <blkiotune> are concatenated into a single string attribute under
> virDomain{Get,Set}BlkioParameters, named "device_weight".
>
> Signed-off-by: Hu Tao <hutao at cn.fujitsu.com>
> Signed-off-by: Eric Blake <eblake at redhat.com>
> ---
> docs/formatdomain.html.in | 29 +++++-
> docs/schemas/domaincommon.rng | 26 ++++-
> include/libvirt/libvirt.h.in | 10 ++
> src/conf/domain_conf.c | 99 +++++++++++++++++++-
> src/conf/domain_conf.h | 14 +++
> src/libvirt_private.syms | 1 +
> .../qemuxml2argv-blkiotune-device.xml | 36 +++++++
> tools/virsh.c | 43 +++++++--
> tools/virsh.pod | 8 ++-
> 9 files changed, 245 insertions(+), 21 deletions(-)
> create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-blkiotune-device.xml
>
> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> index cbad196..99c5add 100644
> --- a/docs/formatdomain.html.in
> +++ b/docs/formatdomain.html.in
> @@ -505,6 +505,14 @@
> ...
> <blkiotune>
> <weight>800</weight>
> + <device>
> + <path>/dev/sda</path>
> + <weight>1000</weight>
> + </device>
> + <device>
> + <path>/dev/sdb</path>
> + <weight>500</weight>
> + </device>
> </blkiotune>
> ...
> </domain>
> @@ -514,10 +522,25 @@
> <dt><code>blkiotune</code></dt>
> <dd> The optional <code>blkiotune</code> element provides the ability
> to tune Blkio cgroup tunable parameters for the domain. If this is
> - omitted, it defaults to the OS provided defaults.</dd>
> + omitted, it defaults to the OS provided
> + defaults. <span class="since">Since 0.8.8</span></dd>
> <dt><code>weight</code></dt>
> - <dd> The optional <code>weight</code> element is the I/O weight of the
> - guest. The value should be in range [100, 1000].</dd>
> + <dd> The optional <code>weight</code> element is the overall I/O
> + weight of the guest. The value should be in the range [100,
> + 1000].</dd>
> + <dt><code>device</code></dt>
> + <dd>The domain may have multiple <code>device</code> elements
> + that further tune the weights for each host block device in
> + use by the domain. Note that
> + multiple <a href="#elementsDisks">guest disks</a> can share a
> + single host block device, if they are backed by files within
> + the same host file system, which is why this tuning parameter
> + is at the global domain level rather than associated with each
> + guest disk device. Each <code>device</code> element has two
> + mandatory sub-elements, <code>path</code> describing the
> + absolute path of the device, and <code>weight</code> giving
> + the relative weight of that device, in the range [100,
> + 1000]. <span class="since">Since 0.9.8</span></dd>
> </dl>
>
>
> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
> index b6f858e..f776a51 100644
> --- a/docs/schemas/domaincommon.rng
> +++ b/docs/schemas/domaincommon.rng
> @@ -322,12 +322,26 @@
> <!-- The Blkio cgroup related tunables would go in the blkiotune -->
> <optional>
> <element name="blkiotune">
> - <!-- I/O weight the VM can use -->
> - <optional>
> - <element name="weight">
> - <ref name="weight"/>
> - </element>
> - </optional>
> + <interleave>
> + <!-- I/O weight the VM can use -->
> + <optional>
> + <element name="weight">
> + <ref name="weight"/>
> + </element>
> + </optional>
> + <zeroOrMore>
> + <element name="device">
> + <interleave>
> + <element name="path">
> + <ref name="absFilePath"/>
> + </element>
> + <element name="weight">
> + <ref name="weight"/>
> + </element>
> + </interleave>
> + </element>
> + </zeroOrMore>
> + </interleave>
> </element>
> </optional>
>
> diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
> index 2ab89f5..ff4f51b 100644
> --- a/include/libvirt/libvirt.h.in
> +++ b/include/libvirt/libvirt.h.in
> @@ -1236,6 +1236,16 @@ char * virDomainGetSchedulerType(virDomainPtr domain,
>
> #define VIR_DOMAIN_BLKIO_WEIGHT "weight"
>
> +/**
> + * VIR_DOMAIN_BLKIO_DEVICE_WEIGHT:
> + *
> + * Macro for the blkio tunable weight_device: it represents the
> + * per-device weight, as a string. The string is parsed as a
> + * series of /path/to/device,weight elements, separated by ','.
> + */
> +
> +#define VIR_DOMAIN_BLKIO_DEVICE_WEIGHT "device_weight"
> +
> /* Set Blkio tunables for the domain*/
> int virDomainSetBlkioParameters(virDomainPtr domain,
> virTypedParameterPtr params,
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 58f4d0f..b35c83c 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -603,6 +603,67 @@ VIR_ENUM_IMPL(virDomainStartupPolicy, VIR_DOMAIN_STARTUP_POLICY_LAST,
> #define VIR_DOMAIN_XML_WRITE_FLAGS VIR_DOMAIN_XML_SECURE
> #define VIR_DOMAIN_XML_READ_FLAGS VIR_DOMAIN_XML_INACTIVE
>
> +
> +void
> +virBlkioDeviceWeightArrayClear(virBlkioDeviceWeightPtr deviceWeights,
> + int ndevices)
> +{
> + int i;
> +
> + for (i = 0; i < ndevices; i++)
> + VIR_FREE(deviceWeights[i].path);
> +}
> +
> +/**
> + * virDomainBlkioDeviceWeightParseXML
> + *
> + * this function parses a XML node:
> + *
> + * <device>
> + * <path>/fully/qualified/device/path</path>
> + * <weight>weight</weight>
> + * </device>
> + *
> + * and fills a virBlkioDeviceWeight struct.
> + */
> +static int
> +virDomainBlkioDeviceWeightParseXML(xmlNodePtr root,
> + virBlkioDeviceWeightPtr dw)
> +{
> + char *c;
> + xmlNodePtr node;
> +
> + node = root->children;
> + while (node) {
> + if (node->type == XML_ELEMENT_NODE) {
> + if (xmlStrEqual(node->name, BAD_CAST "path") && !dw->path) {
> + dw->path = (char *)xmlNodeGetContent(node);
> + } else if (xmlStrEqual(node->name, BAD_CAST "weight")) {
> + c = (char *)xmlNodeGetContent(node);
> + if (virStrToLong_ui(c, NULL, 10, &dw->weight) < 0) {
> + virDomainReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> + _("could not parse weight %s"),
> + c);
> + VIR_FREE(c);
> + VIR_FREE(dw->path);
> + return -1;
> + }
> + VIR_FREE(c);
> + }
> + }
> + node = node->next;
> + }
> + if (!dw->path) {
> + virDomainReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("missing per-device path"));
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +
> +
> static void
> virDomainObjListDataFree(void *payload, const void *name ATTRIBUTE_UNUSED)
> {
> @@ -1272,6 +1333,10 @@ void virDomainDefFree(virDomainDefPtr def)
> VIR_FREE(def->emulator);
> VIR_FREE(def->description);
>
> + virBlkioDeviceWeightArrayClear(def->blkio.devices,
> + def->blkio.ndevices);
> + VIR_FREE(def->blkio.devices);
> +
> virDomainWatchdogDefFree(def->watchdog);
>
> virDomainMemballoonDefFree(def->memballoon);
> @@ -6711,6 +6776,22 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
> &def->blkio.weight) < 0)
> def->blkio.weight = 0;
>
> + if ((n = virXPathNodeSet("./blkiotune/device", ctxt, &nodes)) < 0) {
> + virDomainReportError(VIR_ERR_INTERNAL_ERROR,
> + "%s", _("cannot extract blkiotune nodes"));
> + goto error;
> + }
> + if (n && VIR_ALLOC_N(def->blkio.devices, n) < 0)
> + goto no_memory;
> +
> + for (i = 0; i < n; i++) {
> + if (virDomainBlkioDeviceWeightParseXML(nodes[i],
> + &def->blkio.devices[i]) < 0)
> + goto error;
> + def->blkio.ndevices++;
> + }
> + VIR_FREE(nodes);
> +
> /* Extract other memory tunables */
> if (virXPathULong("string(./memtune/hard_limit)", ctxt,
> &def->mem.hard_limit) < 0)
> @@ -10849,10 +10930,22 @@ virDomainDefFormatInternal(virDomainDefPtr def,
> def->mem.cur_balloon);
>
> /* add blkiotune only if there are any */
> - if (def->blkio.weight) {
> + if (def->blkio.weight || def->blkio.devices) {
> virBufferAddLit(buf, " <blkiotune>\n");
> - virBufferAsprintf(buf, " <weight>%u</weight>\n",
> - def->blkio.weight);
> +
> + if (def->blkio.weight)
> + virBufferAsprintf(buf, " <weight>%u</weight>\n",
> + def->blkio.weight);
> +
> + for (n = 0; n < def->blkio.ndevices; n++) {
> + virBufferAddLit(buf, " <device>\n");
> + virBufferEscapeString(buf, " <path>%s</path>\n",
> + def->blkio.devices[n].path);
> + virBufferAsprintf(buf, " <weight>%u</weight>\n",
> + def->blkio.devices[n].weight);
> + virBufferAddLit(buf, " </device>\n");
> + }
> +
> virBufferAddLit(buf, " </blkiotune>\n");
> }
We can filter out 0-weight here:
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index b35c83c..5160003 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -10893,6 +10893,7 @@ virDomainDefFormatInternal(virDomainDefPtr def,
char uuidstr[VIR_UUID_STRING_BUFLEN];
const char *type = NULL;
int n, allones = 1;
+ int blkio = 0;
virCheckFlags(DUMPXML_FLAGS |
VIR_DOMAIN_XML_INTERNAL_STATUS |
@@ -10930,7 +10931,15 @@ virDomainDefFormatInternal(virDomainDefPtr def,
def->mem.cur_balloon);
/* add blkiotune only if there are any */
- if (def->blkio.weight || def->blkio.devices) {
+
+ if (def->blkio.weight)
+ blkio = 1;
+ for (n = 0; n < def->blkio.ndevices; n++) {
+ if (def->blkio.devices[n].weight)
+ blkio = 1;
+ }
+
+ if (blkio) {
virBufferAddLit(buf, " <blkiotune>\n");
if (def->blkio.weight)
@@ -10938,6 +10947,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
def->blkio.weight);
for (n = 0; n < def->blkio.ndevices; n++) {
+ if (def->blkio.devices[n].weight == 0)
+ continue;
virBufferAddLit(buf, " <device>\n");
virBufferEscapeString(buf, " <path>%s</path>\n",
def->blkio.devices[n].path);
>
> diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> index a3cb834..d3c6381 100644
> --- a/src/conf/domain_conf.h
> +++ b/src/conf/domain_conf.h
> @@ -1361,6 +1361,17 @@ struct _virDomainNumatuneDef {
> /* Future NUMA tuning related stuff should go here. */
> };
>
> +typedef struct _virBlkioDeviceWeight virBlkioDeviceWeight;
> +typedef virBlkioDeviceWeight *virBlkioDeviceWeightPtr;
> +struct _virBlkioDeviceWeight {
> + char *path;
> + unsigned int weight;
> +};
> +
> +void virBlkioDeviceWeightArrayClear(virBlkioDeviceWeightPtr deviceWeights,
> + int ndevices);
> +
> +
> /*
> * Guest VM main configuration
> *
> @@ -1378,6 +1389,9 @@ struct _virDomainDef {
>
> struct {
> unsigned int weight;
> +
> + size_t ndevices;
> + virBlkioDeviceWeightPtr devices;
> } blkio;
>
> struct {
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index b15a8db..d78fd53 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -231,6 +231,7 @@ virDomainAuditVcpu;
>
>
> # domain_conf.h
> +virBlkioDeviceWeightArrayClear;
> virDiskNameToBusDeviceIndex;
> virDiskNameToIndex;
> virDomainActualNetDefFree;
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-blkiotune-device.xml b/tests/qemuxml2argvdata/qemuxml2argv-blkiotune-device.xml
> new file mode 100644
> index 0000000..3412753
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-blkiotune-device.xml
> @@ -0,0 +1,36 @@
> +<domain type='qemu'>
> + <name>QEMUGuest1</name>
> + <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
> + <memory>219136</memory>
> + <currentMemory>219136</currentMemory>
> + <blkiotune>
> + <weight>800</weight>
> + <device>
> + <path>/dev/sda</path>
> + <weight>400</weight>
> + </device>
> + <device>
> + <path>/dev/sdb</path>
> + <weight>900</weight>
> + </device>
> + </blkiotune>
> + <vcpu>1</vcpu>
> + <os>
> + <type arch='i686' machine='pc'>hvm</type>
> + <boot dev='hd'/>
> + </os>
> + <clock offset='utc'/>
> + <on_poweroff>destroy</on_poweroff>
> + <on_reboot>restart</on_reboot>
> + <on_crash>destroy</on_crash>
> + <devices>
> + <emulator>/usr/bin/qemu</emulator>
> + <disk type='block' device='disk'>
> + <source dev='/dev/HostVG/QEMUGuest1'/>
> + <target dev='hda' bus='ide'/>
> + <address type='drive' controller='0' bus='0' unit='0'/>
> + </disk>
> + <controller type='ide' index='0'/>
> + <memballoon model='virtio'/>
> + </devices>
> +</domain>
> diff --git a/tools/virsh.c b/tools/virsh.c
> index 83dc3c7..a1d2afd 100644
> --- a/tools/virsh.c
> +++ b/tools/virsh.c
> @@ -4648,6 +4648,8 @@ static const vshCmdOptDef opts_blkiotune[] = {
> {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
> {"weight", VSH_OT_INT, VSH_OFLAG_NONE,
> N_("IO Weight in range [100, 1000]")},
> + {"device-weights", VSH_OT_STRING, VSH_OFLAG_NONE,
> + N_("per-device IO Weights, in the form of /path/to/device,weight,...")},
> {"config", VSH_OT_BOOL, 0, N_("affect next boot")},
> {"live", VSH_OT_BOOL, 0, N_("affect running domain")},
> {"current", VSH_OT_BOOL, 0, N_("affect current domain")},
> @@ -4658,6 +4660,7 @@ static bool
> cmdBlkiotune(vshControl * ctl, const vshCmd * cmd)
> {
> virDomainPtr dom;
> + const char *device_weight = NULL;
> int weight = 0;
> int nparams = 0;
> int rv = 0;
> @@ -4702,6 +4705,16 @@ cmdBlkiotune(vshControl * ctl, const vshCmd * cmd)
> }
> }
>
> + rv = vshCommandOptString(cmd, "device-weights", &device_weight);
> + if (rv < 0) {
> + vshError(ctl, "%s",
> + _("Unable to parse string parameter"));
> + goto cleanup;
> + }
> + if (rv > 0) {
> + nparams++;
> + }
> +
> if (nparams == 0) {
> /* get the number of blkio parameters */
> if (virDomainGetBlkioParameters(dom, NULL, &nparams, flags) != 0) {
> @@ -4749,12 +4762,14 @@ cmdBlkiotune(vshControl * ctl, const vshCmd * cmd)
> vshPrint(ctl, "%-15s: %d\n", params[i].field,
> params[i].value.b);
> break;
> + case VIR_TYPED_PARAM_STRING:
> + vshPrint(ctl, "%-15s: %s\n", params[i].field,
> + params[i].value.s);
> + break;
> default:
> vshPrint(ctl, "unimplemented blkio parameter type\n");
> }
> }
> -
> - ret = true;
> } else {
> /* set the blkio parameters */
> params = vshCalloc(ctl, nparams, sizeof(*params));
> @@ -4765,18 +4780,30 @@ cmdBlkiotune(vshControl * ctl, const vshCmd * cmd)
>
> if (weight) {
> temp->value.ui = weight;
> - strncpy(temp->field, VIR_DOMAIN_BLKIO_WEIGHT,
> - sizeof(temp->field));
> - weight = 0;
> + if (!virStrcpy(temp->field, VIR_DOMAIN_BLKIO_WEIGHT,
> + sizeof(temp->field)))
> + goto cleanup;
> + }
> +
> + if (device_weight) {
> + temp->value.s = vshStrdup(ctl, device_weight);
> + temp->type = VIR_TYPED_PARAM_STRING;
> + if (!virStrcpy(temp->field, VIR_DOMAIN_BLKIO_DEVICE_WEIGHT,
> + sizeof(temp->field)))
> + goto cleanup;
> }
> }
> - if (virDomainSetBlkioParameters(dom, params, nparams, flags) != 0)
> +
> + if (virDomainSetBlkioParameters(dom, params, nparams, flags) < 0) {
> vshError(ctl, "%s", _("Unable to change blkio parameters"));
> - else
> - ret = true;
> + goto cleanup;
> + }
> }
>
> + ret = true;
> +
> cleanup:
> + virTypedParameterArrayClear(params, nparams);
> VIR_FREE(params);
> virDomainFree(dom);
> return ret;
> diff --git a/tools/virsh.pod b/tools/virsh.pod
> index 775d302..ef024c5 100644
> --- a/tools/virsh.pod
> +++ b/tools/virsh.pod
> @@ -1032,12 +1032,18 @@ value are kilobytes (i.e. blocks of 1024 bytes).
>
> Specifying -1 as a value for these limits is interpreted as unlimited.
>
> -=item B<blkiotune> I<domain-id> [I<--weight> B<weight>] [[I<--config>]
> +=item B<blkiotune> I<domain-id> [I<--weight> B<weight>]
> +[I<--device-weights> B<device-weights>] [[I<--config>]
> [I<--live>] | [I<--current>]]
>
> Display or set the blkio parameters. QEMU/KVM supports I<--weight>.
> I<--weight> is in range [100, 1000].
>
> +B<device-weights> is a single string listing one or more device/weight
> +pairs, in the format of /path/to/device,weight,/path/to/device,weight.
> +Each weight is in the range [100, 1000], or the value 0 to remove that
> +device from per-device listings.
> +
> If I<--live> is specified, affect a running guest.
> If I<--config> is specified, affect the next boot of a persistent guest.
> If I<--current> is specified, affect the current guest state.
> --
> 1.7.7.1
--
Thanks,
Hu Tao
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