8:36 p.m.
Callers should not need to know what the name of the file to
be read in the Linux-specific version of nodeGetCPUmap;
furthermore, qemu cares about online cpus, not present cpus,
when determining which cpus to skip.
While at it, I fixed the fact that we were computing the maximum
online cpu id by doing a slow iteration, when what we really want
to know is the max available cpu.
* src/nodeinfo.h (nodeGetCPUmap): Rename...
(nodeGetCPUBitmap): ...and simplify signature.
* src/nodeinfo.c (linuxParseCPUmax): New function.
(linuxParseCPUmap): Simplify and alter signature.
(nodeGetCPUBitmap): Change implementation.
* src/libvirt_private.syms (nodeinfo.h): Reflect rename.
* src/qemu/qemu_driver.c (qemuDomainGetPercpuStats): Update
caller.
---
src/libvirt_private.syms | 2 +-
src/nodeinfo.c | 76 +++++++++++++++++++++++++++++++-----------------
src/nodeinfo.h | 5 ++--
src/qemu/qemu_driver.c | 6 ++--
4 files changed, 56 insertions(+), 33 deletions(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 7a87f2b..a9cae52 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -907,7 +907,7 @@ virNodeDeviceObjUnlock;
# nodeinfo.h
nodeCapsInitNUMA;
-nodeGetCPUmap;
+nodeGetCPUBitmap;
nodeGetCPUStats;
nodeGetCellsFreeMemory;
nodeGetFreeMemory;
diff --git a/src/nodeinfo.c b/src/nodeinfo.c
index 8f96b8b..461b5dc 100644
--- a/src/nodeinfo.c
+++ b/src/nodeinfo.c
@@ -755,34 +755,55 @@ cleanup:
return ret;
}
+
+/* Determine the maximum cpu id from a Linux sysfs cpu/present file. */
+static int
+linuxParseCPUmax(const char *path)
+{
+ char *str = NULL;
+ char *tmp;
+ int ret = -1;
+
+ if (virFileReadAll(path, 5 * VIR_DOMAIN_CPUMASK_LEN, &str) < 0) {
+ virReportOOMError();
+ goto cleanup;
+ }
+
+ tmp = str;
+ do {
+ if (virStrToLong_i(tmp, &tmp, 10, &ret) < 0 ||
+ !strchr(",-\n", *tmp)) {
+ virReportError(VIR_ERR_NO_SUPPORT,
+ _("failed to parse %s"), path);
+ ret = -1;
+ goto cleanup;
+ }
+ } while (*tmp++ != '\n');
+ ret++;
+
+cleanup:
+ VIR_FREE(str);
+ return ret;
+}
+
/*
- * Linux maintains cpu bit map. For example, if cpuid=5's flag is not set
- * and max cpu is 7. The map file shows 0-4,6-7. This function parses
- * it and returns cpumap.
+ * Linux maintains cpu bit map under cpu/online. For example, if
+ * cpuid=5's flag is not set and max cpu is 7, the map file shows
+ * 0-4,6-7. This function parses it and returns cpumap.
*/
static virBitmapPtr
-linuxParseCPUmap(int *max_cpuid, const char *path)
+linuxParseCPUmap(int max_cpuid, const char *path)
{
virBitmapPtr map = NULL;
char *str = NULL;
- int max_id = 0, i;
if (virFileReadAll(path, 5 * VIR_DOMAIN_CPUMASK_LEN, &str) < 0) {
virReportOOMError();
goto error;
}
- if (virBitmapParse(str, 0, &map,
- VIR_DOMAIN_CPUMASK_LEN) < 0) {
+ if (virBitmapParse(str, 0, &map, max_cpuid) < 0)
goto error;
- }
-
- i = -1;
- while ((i = virBitmapNextSetBit(map, i)) >= 0) {
- max_id = i;
- }
-
- *max_cpuid = max_id;
VIR_FREE(str);
return map;
@@ -929,21 +950,24 @@ int nodeGetMemoryStats(virConnectPtr conn ATTRIBUTE_UNUSED,
}
virBitmapPtr
-nodeGetCPUmap(virConnectPtr conn ATTRIBUTE_UNUSED,
- int *max_id ATTRIBUTE_UNUSED,
- const char *mapname ATTRIBUTE_UNUSED)
+nodeGetCPUBitmap(virConnectPtr conn ATTRIBUTE_UNUSED,
+ int *max_id ATTRIBUTE_UNUSED)
{
#ifdef __linux__
- char *path;
virBitmapPtr cpumap;
-
- if (virAsprintf(&path, SYSFS_SYSTEM_PATH "/cpu/%s", mapname) < 0) {
- virReportOOMError();
+ int present;
+
+ present = linuxParseCPUmax(SYSFS_SYSTEM_PATH "/cpu/present");
+ /* XXX should we also work on older kernels, like RHEL5, that lack
+ * cpu/present and cpu/online files? Those kernels also lack cpu
+ * hotplugging, so it would be a matter of finding the largest
+ * cpu/cpuNN directory, and creating a map that size with all bits
+ * set. */
+ if (present < 0)
return NULL;
- }
-
- cpumap = linuxParseCPUmap(max_id, path);
- VIR_FREE(path);
+ cpumap = linuxParseCPUmap(present, SYSFS_SYSTEM_PATH "/cpu/online");
+ if (max_id && cpumap)
+ *max_id = present;
return cpumap;
#else
virReportError(VIR_ERR_NO_SUPPORT, "%s",
diff --git a/src/nodeinfo.h b/src/nodeinfo.h
index 2eda846..73c6f51 100644
--- a/src/nodeinfo.h
+++ b/src/nodeinfo.h
@@ -46,9 +46,8 @@ int nodeGetCellsFreeMemory(virConnectPtr conn,
int maxCells);
unsigned long long nodeGetFreeMemory(virConnectPtr conn);
-virBitmapPtr nodeGetCPUmap(virConnectPtr conn,
- int *max_id,
- const char *mapname);
+virBitmapPtr nodeGetCPUBitmap(virConnectPtr conn,
+ int *max_id);
int nodeGetMemoryParameters(virConnectPtr conn,
virTypedParameterPtr params,
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 254f191..57e6403 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -13615,8 +13615,8 @@ qemuDomainGetPercpuStats(virDomainPtr domain,
if (nparams == 0 && ncpus != 0)
return QEMU_NB_PER_CPU_STAT_PARAM;
- /* To parse account file, we need "present" cpu map. */
- map = nodeGetCPUmap(domain->conn, &max_id, "present");
+ /* To parse account file, we need bitmap of online cpus. */
+ map = nodeGetCPUBitmap(domain->conn, &max_id);
if (!map)
return rv;
@@ -13681,7 +13681,7 @@ qemuDomainGetPercpuStats(virDomainPtr domain,
goto cleanup;
/* Check that the mapping of online cpus didn't change mid-parse. */
- map2 = nodeGetCPUmap(domain->conn, &max_id, "present");
+ map2 = nodeGetCPUBitmap(domain->conn, &max_id);
if (!map2 || !virBitmapEqual(map, map2)) {
virReportError(VIR_ERR_OPERATION_INVALID, "%s",
_("the set of online cpus changed while reading"));
--
1.7.11.7