[libvirt] [PATCH 3/3] qemu: fix domain startup failing with 'strict' mode in numatune
If the memory mode is specified as 'strict' and with one node, we
get the following error when starting domain.
error: Unable to write to '$cgroup_path/cpuset.mems': Device or resource busy
XML is configured with numatune as follows:
<numatune>
<memory mode='strict' nodeset='0'/>
</numatune>
It's broken by Commit 411cea638f6ec8503b7142a31e58b1cd85dbeaba
which moved qemuSetupCgroupForEmulator() before setting cpuset.mems
in qemuSetupCgroupPostInit.
Directory '$cgroup_path/emulator/' is created in qemuSetupCgroupForEmulator.
But '$cgroup_path/emulator/cpuset.mems' it not set and has a default value
(all nodes, such as 0-1). Then we setup '$cgroup_path/cpuset.mems' to the
nodemask (in this case it's '0') in qemuSetupCgroupPostInit. It must fail.
This patch makes '$cgroup_path/emulator/cpuset.mems' is set before
'$cgroup_path/cpuset.mems'. The action is similar with that in
qemuDomainSetNumaParamsLive.
Signed-off-by: Wang Rui <moon.wangrui(a)huawei.com>
---
src/qemu/qemu_cgroup.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index a87ef40..3b1d16d 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -611,6 +611,7 @@ static int
qemuSetupCpusetMems(virDomainObjPtr vm,
virBitmapPtr nodemask)
{
+ virCgroupPtr cgroup_temp = NULL;
qemuDomainObjPrivatePtr priv = vm->privateData;
char *mem_mask = NULL;
int ret = -1;
@@ -627,13 +628,16 @@ qemuSetupCpusetMems(virDomainObjPtr vm,
&mem_mask, -1) < 0)
goto cleanup;
- if (mem_mask &&
- virCgroupSetCpusetMems(priv->cgroup, mem_mask) < 0)
- goto cleanup;
+ if (mem_mask)
+ if (virCgroupNewEmulator(priv->cgroup, false, &cgroup_temp) < 0 ||
+ virCgroupSetCpusetMems(cgroup_temp, mem_mask) < 0 ||
+ virCgroupSetCpusetMems(priv->cgroup, mem_mask) < 0)
+ goto cleanup;
ret = 0;
cleanup:
VIR_FREE(mem_mask);
+ virCgroupFree(&cgroup_temp);
return ret;
}
--
1.7.12.4