LXC implement memory control APIs

The patch implements the missing memory control APIs for lxc, i.e.,
domainGetMaxMemory, domainSetMaxMemory, domainSetMemory, and improves
domainGetInfo to return proper amount of used memory via cgroup.

* src/libvirt_private.syms: Export virCgroupGetMemoryUsage
  and add missing virCgroupSetMemory
* src/lxc/lxc_driver.c: Implement missing memory functions
* src/util/cgroup.c, src/util/cgroup.h: Add the function
  to get used memory

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 952ed2968c5fea72357aa3b64513e3956fdfb3cb..37c729c72508f66d58cd59aa4c562dbd717c8a78 100644 (file)
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -53,6 +53,8 @@ virCgroupForDriver;
 virCgroupRemove;
 virCgroupFree;
 virCgroupAddTask;
+virCgroupSetMemory;
+virCgroupGetMemoryUsage;
 virCgroupSetCpuShares;
 virCgroupGetCpuShares;
 virCgroupDenyDevicePath;

diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index 5fb4105a0bd24b3ec7c60da4c91bca6e426488cf..8ec4ae4964cc64ca10325724f708e5e69bedc44b 100644 (file)
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -450,6 +450,7 @@ static int lxcDomainGetInfo(virDomainPtr dom,
 
     if (!virDomainIsActive(vm) || driver->cgroup == NULL) {
         info->cpuTime = 0;
+        info->memory = vm->def->memory;
     } else {
         if (virCgroupForDomain(driver->cgroup, vm->def->name, &cgroup, 0) != 0) {
             lxcError(dom->conn, dom, VIR_ERR_INTERNAL_ERROR,
@@ -458,13 +459,18 @@ static int lxcDomainGetInfo(virDomainPtr dom,
         }
 
         if (virCgroupGetCpuacctUsage(cgroup, &(info->cpuTime)) < 0) {
-            lxcError(dom->conn, dom, VIR_ERR_OPERATION_FAILED, ("cannot read cputime for domain"));
+            lxcError(dom->conn, dom, VIR_ERR_OPERATION_FAILED,
+                     "%s", _("cannot read cputime for domain"));
+            goto cleanup;
+        }
+        if (virCgroupGetMemoryUsage(cgroup, &(info->memory)) < 0) {
+            lxcError(dom->conn, dom, VIR_ERR_OPERATION_FAILED,
+                     "%s", _("cannot read memory usage for domain"));
             goto cleanup;
         }
     }
 
     info->maxMem = vm->def->maxmem;
-    info->memory = vm->def->memory;
     info->nrVirtCpu = 1;
     ret = 0;
 
@@ -501,6 +507,112 @@ cleanup:
     return ret;
 }
 
+/* Returns max memory in kb, 0 if error */
+static unsigned long lxcDomainGetMaxMemory(virDomainPtr dom) {
+    lxc_driver_t *driver = dom->conn->privateData;
+    virDomainObjPtr vm;
+    unsigned long ret = 0;
+
+    lxcDriverLock(driver);
+    vm = virDomainFindByUUID(&driver->domains, dom->uuid);
+    lxcDriverUnlock(driver);
+
+    if (!vm) {
+        char uuidstr[VIR_UUID_STRING_BUFLEN];
+        virUUIDFormat(dom->uuid, uuidstr);
+        lxcError(dom->conn, dom, VIR_ERR_NO_DOMAIN,
+                         _("no domain with matching uuid '%s'"), uuidstr);
+        goto cleanup;
+    }
+
+    ret = vm->def->maxmem;
+
+cleanup:
+    if (vm)
+        virDomainObjUnlock(vm);
+    return ret;
+}
+
+static int lxcDomainSetMaxMemory(virDomainPtr dom, unsigned long newmax) {
+    lxc_driver_t *driver = dom->conn->privateData;
+    virDomainObjPtr vm;
+    int ret = -1;
+
+    lxcDriverLock(driver);
+    vm = virDomainFindByUUID(&driver->domains, dom->uuid);
+    lxcDriverUnlock(driver);
+
+    if (!vm) {
+        char uuidstr[VIR_UUID_STRING_BUFLEN];
+        virUUIDFormat(dom->uuid, uuidstr);
+        lxcError(dom->conn, dom, VIR_ERR_NO_DOMAIN,
+                         _("no domain with matching uuid '%s'"), uuidstr);
+        goto cleanup;
+    }
+
+    if (newmax < vm->def->memory) {
+        lxcError(dom->conn, dom, VIR_ERR_INVALID_ARG,
+                         "%s", _("cannot set max memory lower than current memory"));
+        goto cleanup;
+    }
+
+    vm->def->maxmem = newmax;
+    ret = 0;
+
+cleanup:
+    if (vm)
+        virDomainObjUnlock(vm);
+    return ret;
+}
+
+static int lxcDomainSetMemory(virDomainPtr dom, unsigned long newmem) {
+    lxc_driver_t *driver = dom->conn->privateData;
+    virDomainObjPtr vm;
+    virCgroupPtr cgroup = NULL;
+    int ret = -1;
+
+    lxcDriverLock(driver);
+    vm = virDomainFindByUUID(&driver->domains, dom->uuid);
+    lxcDriverUnlock(driver);
+    if (!vm) {
+        char uuidstr[VIR_UUID_STRING_BUFLEN];
+        virUUIDFormat(dom->uuid, uuidstr);
+        lxcError(dom->conn, dom, VIR_ERR_NO_DOMAIN,
+                 _("no domain with matching uuid '%s'"), uuidstr);
+        goto cleanup;
+    }
+
+    if (newmem > vm->def->maxmem) {
+        lxcError(dom->conn, dom, VIR_ERR_INVALID_ARG,
+                 "%s", _("cannot set memory higher than max memory"));
+        goto cleanup;
+    }
+
+    if (virDomainIsActive(vm)) {
+        if (virCgroupForDomain(driver->cgroup, vm->def->name, &cgroup, 0) != 0) {
+            lxcError(dom->conn, dom, VIR_ERR_INTERNAL_ERROR,
+                     _("Unable to get cgroup for %s\n"), vm->def->name);
+            goto cleanup;
+        }
+
+        if (virCgroupSetMemory(cgroup, newmem) < 0) {
+            lxcError(dom->conn, dom, VIR_ERR_OPERATION_FAILED,
+                     "%s", _("cannot set memory for domain"));
+            goto cleanup;
+        }
+    } else {
+        vm->def->memory = newmem;
+    }
+    ret = 0;
+
+cleanup:
+    if (vm)
+        virDomainObjUnlock(vm);
+    if (cgroup)
+        virCgroupFree(&cgroup);
+    return ret;
+}
+
 static char *lxcDomainDumpXML(virDomainPtr dom,
                               int flags)
 {
@@ -2103,9 +2215,9 @@ static virDriver lxcDriver = {
     NULL, /* domainReboot */
     lxcDomainDestroy, /* domainDestroy */
     lxcGetOSType, /* domainGetOSType */
-    NULL, /* domainGetMaxMemory */
-    NULL, /* domainSetMaxMemory */
-    NULL, /* domainSetMemory */
+    lxcDomainGetMaxMemory, /* domainGetMaxMemory */
+    lxcDomainSetMaxMemory, /* domainSetMaxMemory */
+    lxcDomainSetMemory, /* domainSetMemory */
     lxcDomainGetInfo, /* domainGetInfo */
     NULL, /* domainSave */
     NULL, /* domainRestore */

diff --git a/src/util/cgroup.c b/src/util/cgroup.c
index 2e646fdf615967ceaffa3f1169719c14feab1daa..e56d293188ba423d41d0b4519eb4285d53d8ebfc 100644 (file)
--- a/src/util/cgroup.c
+++ b/src/util/cgroup.c
@@ -701,6 +701,26 @@ int virCgroupSetMemory(virCgroupPtr group, unsigned long kb)
                                 kb << 10);
 }
 
+/**
+ * virCgroupGetMemoryUsage:
+ *
+ * @group: The cgroup to change memory for
+ * @kb: Pointer to returned used memory in kilobytes
+ *
+ * Returns: 0 on success
+ */
+int virCgroupGetMemoryUsage(virCgroupPtr group, unsigned long *kb)
+{
+    uint64_t usage_in_bytes;
+    int ret;
+    ret = virCgroupGetValueU64(group,
+                               VIR_CGROUP_CONTROLLER_MEMORY,
+                               "memory.usage_in_bytes", &usage_in_bytes);
+    if (ret == 0)
+        *kb = (unsigned long) usage_in_bytes >> 10;
+    return ret;
+}
+
 /**
  * virCgroupDenyAllDevices:
  *

diff --git a/src/util/cgroup.h b/src/util/cgroup.h
index aba56c69cd0ae4b0de803df032268c49c90fa0cf..aa36632c166ba8e48d42b902baa8bdd12b83a8d5 100644 (file)
--- a/src/util/cgroup.h
+++ b/src/util/cgroup.h
@@ -41,6 +41,7 @@ int virCgroupForDomain(virCgroupPtr driver,
 int virCgroupAddTask(virCgroupPtr group, pid_t pid);
 
 int virCgroupSetMemory(virCgroupPtr group, unsigned long kb);
+int virCgroupGetMemoryUsage(virCgroupPtr group, unsigned long *kb);
 
 int virCgroupDenyAllDevices(virCgroupPtr group);