On 10/02/2018 10:44 AM, Pavel Hrdina wrote:
> 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@xxxxxxxxxx>
> ---
> 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;
> + }
So a loop like this appears all over the patch:
for (i = 0; i < VIR_CGROUP_BACKEND_TYPE_LAST; i++) {
if (group->backends[i] &&
group->backends[i]->cb();
}
I wonder if we should have wrappers around these chunks of code. But
that could be saved as a follow up patch.
> }
> }
>
> @@ -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;
No need to remove the 'break'.
> }
> }
ACK
Michal
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