Re: [PATCH v4 5/5] lxc: Count max VCPUs based on cpuset.cpus in native config

Native config files sometimes can setup cpuset.cpus to pin some CPUs. Before this, LXC was using a fixed number of 1 VCPU. After this commit, XML definition will generate a dynamic number of VCPUs based on that cgroup attribute.

Signed-off-by: Julio Faracco <jcfaracco(a)gmail.com&gt; --- src/lxc/lxc_container.c | 23 ++++++++++++++++++ src/lxc/lxc_container.h | 2 ++ src/lxc/lxc_native.c | 24 +++++++++++++++++-- .../lxcconf2xml-cpusettune.xml | 2 +- 4 files changed, 48 insertions(+), 3 deletions(-) diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index 88e27f3060..c5788e5c32 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -2487,3 +2487,26 @@ int lxcContainerChown(virDomainDefPtr def, const char *path) return 0; } + + +int lxcContainerGetMaxCpusInCpuset(const char *cpuset) +{ + const char *c = cpuset; + int max_cpu = 0; + + while (c) { + int a, b, ret; + + ret = sscanf(c, "%d-%d", &a, &b); + if (ret == 1) + max_cpu++; + else if (ret == 2) + max_cpu += a > b ? a - b + 1 : b - a + 1; + + if (!(c = strchr(c+1, ','))) + break; + c++; + } + + return max_cpu; +} diff --git a/src/lxc/lxc_container.h b/src/lxc/lxc_container.h index 94a6c5309c..6f112e0667 100644 --- a/src/lxc/lxc_container.h +++ b/src/lxc/lxc_container.h @@ -63,3 +63,5 @@ virArch lxcContainerGetAlt32bitArch(virArch arch); int lxcContainerChown(virDomainDefPtr def, const char *path); bool lxcIsBasicMountLocation(const char *path); + +int lxcContainerGetMaxCpusInCpuset(const char *cpuset); diff --git a/src/lxc/lxc_native.c b/src/lxc/lxc_native.c index 02d2bf33e4..409bf00bd2 100644 --- a/src/lxc/lxc_native.c +++ b/src/lxc/lxc_native.c @@ -993,6 +993,24 @@ lxcSetCpusetTune(virDomainDefPtr def, virConfPtr properties) return 0; } + +static int +lxcGetVCpuMax(virConfPtr properties) +{ + g_autofree char *value = NULL; + int vcpumax = 1; + + if (virConfGetValueString(properties, "lxc.cgroup.cpuset.cpus", + &value) > 0) { + vcpumax = lxcContainerGetMaxCpusInCpuset(value); + if (vcpumax > 0) + return vcpumax; + } + + return vcpumax; +} + + static int lxcBlkioDeviceWalkCallback(const char *name, virConfValuePtr value, void *data) { @@ -1132,6 +1150,7 @@ lxcParseConfigString(const char *config, virDomainDefPtr vmdef = NULL; g_autoptr(virConf) properties = NULL; g_autofree char *value = NULL; + int vcpumax; if (!(properties = virConfReadString(config, VIR_CONF_FLAG_LXC_FORMAT))) return NULL; @@ -1155,10 +1174,11 @@ lxcParseConfigString(const char *config, /* Value not handled by the LXC driver, setting to * minimum required to make XML parsing pass */ - if (virDomainDefSetVcpusMax(vmdef, 1, xmlopt) < 0) + vcpumax = lxcGetVCpuMax(properties); + if (virDomainDefSetVcpusMax(vmdef, vcpumax, xmlopt) < 0) goto error; - if (virDomainDefSetVcpus(vmdef, 1) < 0) + if (virDomainDefSetVcpus(vmdef, vcpumax) < 0) goto error; vmdef->nfss = 0; diff --git a/tests/lxcconf2xmldata/lxcconf2xml-cpusettune.xml b/tests/lxcconf2xmldata/lxcconf2xml-cpusettune.xml index 6df089d00f..a1fec12d9b 100644 --- a/tests/lxcconf2xmldata/lxcconf2xml-cpusettune.xml +++ b/tests/lxcconf2xmldata/lxcconf2xml-cpusettune.xml @@ -3,7 +3,7 @@ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid> <memory unit='KiB'>65536</memory> <currentMemory unit='KiB'>65536</currentMemory> - <vcpu placement='static' cpuset='1-2,5-7'>1</vcpu> + <vcpu placement='static' cpuset='1-2,5-7'>5</vcpu> <numatune> <memory mode='strict' nodeset='1-4'/> </numatune> -- 2.20.1