On 17.12.2015 23:25, John Ferlan wrote:
On 12/14/2015 06:35 AM, Dmitry Andreev wrote:
Excessive memory balloon inflation can cause invocation of OOM-killer, when Linux is under severe memory pressure. QEMU memballoon device has a feature to release some memory at the last moment before some process will be get killed by OOM-killer.
Introduced attribute allows to enable or disable this feature. --- docs/formatdomain.html.in | 10 ++++++++++ docs/schemas/domaincommon.rng | 5 +++++ src/conf/domain_conf.c | 23 +++++++++++++++++++++++ src/conf/domain_conf.h | 1 + 4 files changed, 39 insertions(+)
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index a8bd48e..fa68e7b 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -5954,6 +5954,16 @@ qemu-kvm -net nic,model=? /dev/null <li>'xen' — default with Xen</li> </ul> </dd> + <dt><code>deflate-on-oom</code></dt> + <dd> + <p> + The optional <code>deflate-on-oom</code> attribute allows to + enable/disable (values "on"/"off", respectively) the ability of the + QEMU virtio memory balloon to release some memory at the last moment + before a guest's process get killed by OOM-killer. + <span class="since">Since 1.3.1, QEMU and KVM only</span> + </p> + </dd> <dt><code>period</code></dt> <dd> <p> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 4804c69..9587849 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -3415,6 +3415,11 @@ <value>none</value> </choice> </attribute> + <optional> + <attribute name="deflate-on-oom">
Typically don't want those "-", either use some sort of single word or other attributes to have "_"
Is it OK to use 'deflation' or 'deflate' word? Can't choose the name by myself.
This will of course have ramifications throughout the code. I'll only mention it here though.
+ <ref name="virOnOff"/> + </attribute> + </optional> <interleave> <optional> <ref name="alias"/> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 5200c27..b332097 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -11312,6 +11312,7 @@ virDomainMemballoonDefParseXML(xmlNodePtr node, unsigned int flags) { char *model; + char *deflate; virDomainMemballoonDefPtr def; xmlNodePtr save = ctxt->node; unsigned int period = 0; @@ -11332,6 +11333,13 @@ virDomainMemballoonDefParseXML(xmlNodePtr node, goto error; }
+ if ((deflate = virXMLPropString(node, "deflate-on-oom")) && + (def->deflate = virTristateSwitchTypeFromString(deflate)) < 0) {
Since you're not using/allowing "default", then the comparison should be <= 0
yes, there are some others that are not correct it seems.
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("invalid deflate-on-oom attribute value '%s'"), deflate); + goto error; + } + ctxt->node = node; if (virXPathUInt("string(./stats/@period)", ctxt, &period) < -1) { virReportError(VIR_ERR_XML_ERROR, "%s", @@ -11350,6 +11358,7 @@ virDomainMemballoonDefParseXML(xmlNodePtr node,
cleanup: VIR_FREE(model); + VIR_FREE(deflate);
ctxt->node = save; return def; @@ -17223,6 +17232,15 @@ virDomainMemballoonDefCheckABIStability(virDomainMemballoonDefPtr src, return false; }
+ if (src->deflate != dst->deflate) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Target balloon deflate-on-oom attribute value " + "%s does not match source %s"), + virTristateSwitchTypeToString(dst->deflate), + virTristateSwitchTypeToString(src->deflate)); + return false; + } + if (!virDomainDeviceInfoCheckABIStability(&src->info, &dst->info)) return false;
@@ -20390,6 +20408,7 @@ virDomainMemballoonDefFormat(virBufferPtr buf, unsigned int flags) { const char *model = virDomainMemballoonModelTypeToString(def->model); + const char *deflate = virTristateSwitchTypeToString(def->deflate); virBuffer childrenBuf = VIR_BUFFER_INITIALIZER; int indent = virBufferGetIndent(buf, false);
@@ -20400,6 +20419,10 @@ virDomainMemballoonDefFormat(virBufferPtr buf, }
virBufferAsprintf(buf, "<memballoon model='%s'", model); + + if (def->deflate > 0 && deflate)
This would be use of def->deflate != VIR_TRISTATE_SWITCH_ABSENT
+ virBufferAsprintf(buf, " deflate-on-oom='%s'", deflate);
The 'deflate' isn't required - see other examples.
Looks OK otherwise.
John
+ virBufferAdjustIndent(&childrenBuf, indent + 2);
if (def->period) diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index cec681a..707ffb2 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1634,6 +1634,7 @@ struct _virDomainMemballoonDef { int model; virDomainDeviceInfo info; int period; /* seconds between collections */ + int deflate; /* enum virTristateSwitch */ };
struct _virDomainNVRAMDef {