Re: [libvirt] [PATCH] Fix virCgroupGetPercpuStats with non-continuous present CPUs
On 01/22/2015 04:26 AM, Ján Tomko wrote:
Per-cpu stats are only shown for present CPUs in the cgroups,
but we were only parsing the largest CPU number from
/sys/devices/system/cpu/present and looking for stats even for
non-present CPUs.
This resulted in:
internal error: cpuacct parse error
---
cfg.mk | 2 +-
src/nodeinfo.c | 17 +++++++++++++++++
src/nodeinfo.h | 1 +
src/util/vircgroup.c | 24 ++++++++++++++++++------
tests/vircgroupmock.c | 44 ++++++++++++++++++++++++++++++++++++++------
tests/vircgrouptest.c | 47 +++++++++++++++++++++++++++++++++++------------
6 files changed, 110 insertions(+), 25 deletions(-)
+++ b/tests/vircgroupmock.c
@@ -51,6 +51,8 @@ const char *fakedevicedir1 = FAKEDEVDIR1;
# define SYSFS_PREFIX "/not/really/sys/fs/cgroup/"
+# define SYSFS_CPU_PRESENT "/sys/devices/system/cpu/present"
+# define SYSFS_CPU_PRESENT_MOCKED "devices_system_cpu_present"
This mock file is not working on RHEL 5:
+++ b/tests/vircgrouptest.c
@@ -538,12 +538,35 @@ static int testCgroupGetPercpuStats(const void *args
ATTRIBUTE_UNUSED)
virCgroupPtr cgroup = NULL;
size_t i;
int rv, ret = -1;
- virTypedParameter params[2];
+ virTypedParameterPtr params = NULL;
+# define EXPECTED_NCPUS 160
@@ -553,37 +576,37 @@ static int testCgroupGetPercpuStats(const void
*args ATTRIBUTE_UNUSED)
goto cleanup;
}
- if (nodeGetCPUCount() < 1) {
+ if (nodeGetCPUCount() != EXPECTED_NCPUS) {
On Fedora 21, I see the mocking kicking in during linuxParseCPUmax():
nodeGetCPUCount () at nodeinfo.c:1209
1209 {
(gdb) n
1216 char *cpupath = NULL;
(gdb)
1219 if (virFileExists(SYSFS_SYSTEM_PATH "/cpu/present")) {
(gdb)
1220 ncpu = linuxParseCPUmax(SYSFS_SYSTEM_PATH "/cpu/present");
(gdb)
1237 VIR_FREE(cpupath);
(gdb) p ncpu
$1 = 160
but in RHEL 5, we aren't mocking the virFileExists() gate, and I see:
nodeGetCPUCount () at nodeinfo.c:1209
1209 {
(gdb) n
1216 char *cpupath = NULL;
(gdb)
1219 if (virFileExists(SYSFS_SYSTEM_PATH "/cpu/present")) {
(gdb)
1221 } else if (virFileExists(SYSFS_SYSTEM_PATH "/cpu/cpu0")) {
(gdb)
1225 VIR_FREE(cpupath);
(gdb)
1224 ncpu++;
(gdb)
1225 VIR_FREE(cpupath);
(gdb)
1226 if (virAsprintf(&cpupath, "%s/cpu/cpu%d",
(gdb) fin
Run till exit from #0 nodeGetCPUCount () at nodeinfo.c:1226
0x0804ae19 in testCgroupGetPercpuStats (args=0x0) at vircgrouptest.c:659
659 if (nodeGetCPUCount() != EXPECTED_NCPUS) {
Value returned is $1 = 3
I didn't investigate further, but we need to improve the mock code so
that virFileExists(SYSFS_SYSTEM_PATH "/cpu/present") works even when run
on an older kernel where it is not natively present.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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