Re: [libvirt] [PATCH 42/53] vircgroup: add support for hybrid configuration

This enables to use both cgroup v1 and v2 at the same time together with libvirt. It is supported by kernel and there is valid use-case, not all controllers are implemented in cgroup v2 so there might be configurations where administrator would enable these missing controllers in cgroup v1. Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; --- src/util/vircgroup.c | 351 ++++++++++++++++++++++++++---------- src/util/vircgroupbackend.c | 20 ++ src/util/vircgroupbackend.h | 16 +- src/util/vircgrouppriv.h | 2 +- 4 files changed, 291 insertions(+), 98 deletions(-) diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c index dc249bfe33..4aec5f1bcf 100644 --- a/src/util/vircgroup.c +++ b/src/util/vircgroup.c @@ -228,6 +228,7 @@ virCgroupDetectMounts(virCgroupPtr group) struct mntent entry; char buf[CGROUP_MAX_VAL]; int ret = -1; + size_t i; mounts = fopen("/proc/mounts", "r"); if (mounts == NULL) { @@ -236,11 +237,14 @@ virCgroupDetectMounts(virCgroupPtr group) } while (getmntent_r(mounts, &entry, buf, sizeof(buf)) != NULL) { - if (group->backend->detectMounts(group, - entry.mnt_type, - entry.mnt_opts, - entry.mnt_dir) < 0) { - goto cleanup; + for (i = 0; i < VIR_CGROUP_BACKEND_TYPE_LAST; i++) { + if (group->backends[i] && + group->backends[i]->detectMounts(group, + entry.mnt_type, + entry.mnt_opts, + entry.mnt_dir) < 0) { + goto cleanup; + } } } @@ -303,6 +307,7 @@ virCgroupDetectPlacement(virCgroupPtr group, } while (fgets(line, sizeof(line), mapping) != NULL) { + size_t i; char *controllers = strchr(line, ':'); char *selfpath = controllers ? strchr(controllers + 1, ':') : NULL; char *nl = selfpath ? strchr(selfpath, '\n') : NULL; @@ -317,9 +322,12 @@ virCgroupDetectPlacement(virCgroupPtr group, controllers++; selfpath++; - if (group->backend->detectPlacement(group, path, controllers, - selfpath) < 0) { - goto cleanup; + for (i = 0; i < VIR_CGROUP_BACKEND_TYPE_LAST; i++) { + if (group->backends[i] && + group->backends[i]->detectPlacement(group, path, controllers, + selfpath) < 0) { + goto cleanup; + }

} } @@ -338,8 +346,9 @@ virCgroupDetect(virCgroupPtr group, const char *path, virCgroupPtr parent) { - int rc; size_t i; + bool backendAvailable = false; + int controllersAvailable = 0; virCgroupBackendPtr *backends = virCgroupBackendGetAll(); VIR_DEBUG("group=%p controllers=%d path=%s parent=%p", @@ -350,31 +359,40 @@ virCgroupDetect(virCgroupPtr group, for (i = 0; i < VIR_CGROUP_BACKEND_TYPE_LAST; i++) { if (backends[i] && backends[i]->available()) { - group->backend = backends[i]; - break; + group->backends[i] = backends[i]; + backendAvailable = true;

} }