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

On 10/02/2018 10:43 AM, Pavel Hrdina wrote: > 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; I'd put a comment here describing what you do in the commit message. Sure I can go to commit message if I want to, but a comment is more handy.

> + > + 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, > }; > > > ACK Michal