Re: [libvirt] [PATCH 10/53] vircgroup: introduce virCgroupV2DetectControllers

Cgroup v2 has only single mount point for all controllers. The list of controllers is stored in cgroup.controllers file, name of controllers are separated by space. In cgroup v2 there is no cpuacct controller, the cpu.stat file always exists with usage stats. Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; --- src/util/vircgroupv2.c | 67 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) diff --git a/src/util/vircgroupv2.c b/src/util/vircgroupv2.c index d4e0366780..3200338fe3 100644 --- a/src/util/vircgroupv2.c +++ b/src/util/vircgroupv2.c @@ -32,6 +32,7 @@ #include "vircgroup.h" #include "vircgroupbackend.h" #include "vircgroupv2.h" +#include "virerror.h" #include "virfile.h" #include "virlog.h" #include "virstring.h" @@ -232,6 +233,71 @@ virCgroupV2StealPlacement(virCgroupPtr group) } +static int +virCgroupV2ParseControllersFile(virCgroupPtr group) +{ + int rc; + VIR_AUTOFREE(char *) contStr = NULL; + VIR_AUTOFREE(char *) contFile = NULL; + char **contList = NULL; + char **tmp; + + if (virAsprintf(&contFile, "%s/cgroup.controllers", + group->unified.mountPoint) < 0) + return -1; + + rc = virFileReadAll(contFile, 1024 * 1024, &contStr); + if (rc < 0) { + virReportSystemError(errno, _("Unable to read from '%s'"), contFile); + return -1; + } + + virTrimSpaces(contStr, NULL); + + contList = virStringSplit(contStr, " ", 20); + if (!contList) + return -1; + + tmp = contList; + + while (*tmp) { + int type = virCgroupV2ControllerTypeFromString(*tmp); + + if (type >= 0) + group->unified.controllers |= 1 << type; + + tmp++; + } + + virStringListFree(contList); + + return 0; +} + + +static int +virCgroupV2DetectControllers(virCgroupPtr group, + int controllers) +{ + size_t i; + + if (virCgroupV2ParseControllersFile(group) < 0) + return -1; + + group->unified.controllers |= 1 << VIR_CGROUP_CONTROLLER_CPUACCT;

+ + for (i = 0; i < VIR_CGROUP_CONTROLLER_LAST; i++) + VIR_DEBUG("Controller '%s' present=%s", + virCgroupV2ControllerTypeToString(i), + (group->unified.controllers & 1 << i) ? "yes" : "no"); + + if (controllers >= 0) + return controllers & group->unified.controllers; + else + return group->unified.controllers; +} + + virCgroupBackend virCgroupV2Backend = { .type = VIR_CGROUP_BACKEND_TYPE_V2, @@ -243,6 +309,7 @@ virCgroupBackend virCgroupV2Backend = { .detectPlacement = virCgroupV2DetectPlacement, .validatePlacement = virCgroupV2ValidatePlacement, .stealPlacement = virCgroupV2StealPlacement, + .detectControllers = virCgroupV2DetectControllers, };