On 07/30/2014 11:41 PM, Chen Hanxiao wrote:
Currently, setmaxmem return success on an active
domain, but nothing happened.
Not quite true... Prior to these changes...
# virsh -c lxc:/// start vm1
# virsh -c lxc:/// dominfo vm1 | grep memory
Max memory: 50 KiB
Used memory:776 KiB
# virsh -c lxc:/// dumpxml vm1 | grep mem
memory unit='KiB'50/memory
# cat /sys/fs/cgroup/memory/machine.slice/*/memory.limit_in_bytes
51200
# virsh -c lxc:/// setmaxmem vm1 525000
# virsh -c lxc:/// dominfo vm1 | grep memory
Max memory: 525000 KiB
Used memory:776 KiB
# virsh -c lxc:/// dumpxml vm1 | grep mem
memory unit='KiB'525000/memory
# cat /sys/fs/cgroup/memory/machine.slice/*/memory.limit_in_bytes
51200
# virsh -c lxc:/// console vm1
Connected to domain vm1
Escape character is ^]
sh-4.2# grep Mem /proc/meminfo
MemTotal: 50 kB
MemFree: 499076 kB
MemAvailable:3629632 kB
#
Now I'll agree that technically what one expected to happen didn't since
it's not supported, but something did happen :-)... And of course after
a destroy the maxmem went back to 50.
This patch will disable this behaviour,
also add support persistent config.
And it will be used in a later patch.
FWIW:
I agree with Peter's observation from your v1 - the two patches should
be one as it is clearer that way what you are doing and leaves no doubt
why the flag is used
I do see that other drivers like qemu libxl use the MEM_MAXIMUM flag.
So perhaps said differently -
This patch changes the LXC driver setmaxmem function to support the
'--live', '--config', and '--current' flags by revectoring the code
through the setmem function using the VIR_DOMAIN_MEM_MAXIMUM flag. The
setmem code is refactored to handle both cases depending on the flag.
The changed maxmem code for the MEM_MAXIMUM path will not allow
modification to the memory values of an active guest unless the --config
switch is used.
Signed-off-by: Chen Hanxiao chenhanx...@cn.fujitsu.com
---
v2: disable changing max memory on an active domain
drop useless as_assert
src/lxc/lxc_driver.c | 64
+---
1 file changed, 41 insertions(+), 23 deletions(-)
diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index 9e12ecc..d99ab3b 100644
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -721,10 +721,10 @@ static int lxcDomainSetMemoryFlags(virDomainPtr dom,
unsigned long newmem,
virLXCDomainObjPrivatePtr priv;
virLXCDriverPtr driver = dom-conn-privateData;
virLXCDriverConfigPtr cfg = NULL;
-unsigned long oldmax = 0;
virCheckFlags(VIR_DOMAIN_AFFECT_LIVE |
- VIR_DOMAIN_AFFECT_CONFIG, -1);
+ VIR_DOMAIN_AFFECT_CONFIG |
+ VIR_DOMAIN_MEM_MAXIMUM, -1);
if (!(vm = lxcDomObjFromDomain(dom)))
goto cleanup;
@@ -743,32 +743,50 @@ static int lxcDomainSetMemoryFlags(virDomainPtr dom,
unsigned long newmem,
persistentDef) 0)
goto cleanup;
I see the next set of changes is essentially cut-n-pasted from qemu,
although the changes after the else are the same as the former setmem
function - it's just the git diff that obfuscates that.
The changes do work as I'd expect, so ACK from that point of view.
I can merge the two patches for you and commit, but I'll give it a bit
to make sure no one else has concerns
John
-if (flags VIR_DOMAIN_AFFECT_LIVE)
-oldmax = vm-def-mem.max_balloon;
-if (flags VIR_DOMAIN_AFFECT_CONFIG) {
-if (!oldmax || oldmax persistentDef-mem.max_balloon)
-oldmax = persistentDef-mem.max_balloon;
-}
+if (flags VIR_DOMAIN_MEM_MAXIMUM) {
+if (flags VIR_DOMAIN_AFFECT_LIVE) {
+virReportError(VIR_ERR_OPERATION_INVALID, %s,
+ _(Cannot resize the max memory
+ on an active domain));
+goto cleanup;
+}
-if (newmem oldmax) {
-virReportError(VIR_ERR_INVALID_ARG,
- %s, _(Cannot set memory higher than max memory));
-goto cleanup;
-}
+if (flags VIR_DOMAIN_AFFECT_CONFIG) {
+persistentDef-mem.max_balloon = newmem;
+if (persistentDef-mem.cur_balloon newmem)
+persistentDef-mem.cur_balloon = newmem;
+if (virDomainSaveConfig(cfg-configDir, persistentDef) 0)
+goto cleanup;
+}
+} else {
+unsigned long oldmax = 0;
-if (flags VIR_DOMAIN_AFFECT_LIVE) {
-if (virCgroupSetMemory(priv-cgroup, newmem) 0) {
-virReportError(VIR_ERR_OPERATION_FAILED,
- %s, _(Failed to set memory for domain));
-goto cleanup;
+if (flags VIR_DOMAIN_AFFECT_LIVE)
+oldmax = vm-def-mem.max_balloon;
+if (flags
