[libvirt] [PATCH v4 07/13] Implement driver interface domainGetMemoryParamters for QEmu
Daniel Veillard
veillard at redhat.com
Tue Oct 12 15:51:54 UTC 2010
On Fri, Oct 08, 2010 at 05:45:55PM +0530, Nikunj A. Dadhania wrote:
> From: Nikunj A. Dadhania <nikunj at linux.vnet.ibm.com>
>
> V4:
> * prototype change: add unsigned int flags
>
> Driver interface for getting memory parameters, eg. hard_limit, soft_limit and
> swap_hard_limit.
>
> Signed-off-by: Nikunj A. Dadhania <nikunj at linux.vnet.ibm.com>
> ---
> src/qemu/qemu_driver.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 119 insertions(+), 1 deletions(-)
>
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 471db39..8eaa762 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -9458,6 +9458,124 @@ cleanup:
> return ret;
> }
same things about crashing if the arguments are invalid
> + if ((*nparams) == 0) {
> + /* Current number of memory parameters supported by cgroups is 3
> + * FIXME: Magic number, need to see where should this go
> + */
> + *nparams = 3;
> + ret = 0;
> + goto cleanup;
> + }
> +
> + if ((*nparams) != 3) {
using QEMU_NB_MEM_PARAM instead of the raw 3 value c.f. previous patch
comment
> + qemuReportError(VIR_ERR_INVALID_ARG,
> + "%s", _("Invalid parameter count"));
> + goto cleanup;
> + }
okay, this mean the application must always call with 0 first to get
the exact value or this will break, fine but probably need to be made
more clear from the description in libvirt.c .... TODO
> + if (virCgroupForDomain(driver->cgroup, vm->def->name, &group, 0) != 0) {
> + qemuReportError(VIR_ERR_INTERNAL_ERROR,
> + _("cannot find cgroup for domain %s"), vm->def->name);
> + goto cleanup;
> + }
> +
> + for (i = 0; i < *nparams; i++) {
> + virMemoryParameterPtr param = ¶ms[i];
> + val = 0;
> + param->value.ul = 0;
> + param->type = VIR_DOMAIN_MEMORY_FIELD_ULLONG;
> +
> + switch(i) {
> + case 0: /* fill memory hard limit here */
> + rc = virCgroupGetMemoryHardLimit(group, &val);
> + if (rc != 0) {
> + virReportSystemError(-rc, "%s",
> + _("unable to get memory hard limit"));
> + continue;
> + }
> + if (virStrcpyStatic(param->field, VIR_DOMAIN_MEMORY_HARD_LIMIT) == NULL) {
> + qemuReportError(VIR_ERR_INTERNAL_ERROR,
> + "%s", _("Field memory hard limit too long for destination"));
> + continue;
> + }
> + param->value.ul = val;
> + break;
> +
> + case 1: /* fill memory soft limit here */
> + rc = virCgroupGetMemorySoftLimit(group, &val);
> + if (rc != 0) {
> + virReportSystemError(-rc, "%s",
> + _("unable to get memory soft limit"));
> + continue;
> + }
> + if (virStrcpyStatic(param->field, VIR_DOMAIN_MEMORY_SOFT_LIMIT) == NULL) {
> + qemuReportError(VIR_ERR_INTERNAL_ERROR,
> + "%s", _("Field memory soft limit too long for destination"));
> + continue;
> + }
> + param->value.ul = val;
> + break;
> +
> + case 2: /* fill swap hard limit here */
> + rc = virCgroupGetSwapHardLimit(group, &val);
> + if (rc != 0) {
> + virReportSystemError(-rc, "%s",
> + _("unable to get swap hard limit"));
> + continue;
> + }
> + if (virStrcpyStatic(param->field, VIR_DOMAIN_SWAP_HARD_LIMIT) == NULL) {
> + qemuReportError(VIR_ERR_INTERNAL_ERROR,
> + "%s", _("Field swap hard limit too long for destination"));
> + continue;
> + }
> + param->value.ul = val;
> + break;
> +
> + default:
> + break;
> + /* should not hit here */
> + }
> + }
Okay, I'm not sure we actually need a loop here, but it may help
refactoring...
I'm still having a problem with the code ignoring any error occuring in
the loop, and fixing this in the same way. If there is an error the
application *must* learn about it instead of trusting uninitialized
memory as being data !
Maybe a memset is in order actually before entering that loop to avoid
edge case problems... TODO too
> + ret = 0;
> +
> +cleanup:
> + if (group)
> + virCgroupFree(&group);
> + if (vm)
> + virDomainObjUnlock(vm);
> + qemuDriverUnlock(driver);
> + return ret;
> +}
> +
> static int qemuSetSchedulerParameters(virDomainPtr dom,
> virSchedParameterPtr params,
> int nparams)
> @@ -12804,7 +12922,7 @@ static virDriver qemuDriver = {
> qemuDomainSnapshotDelete, /* domainSnapshotDelete */
> qemuDomainMonitorCommand, /* qemuDomainMonitorCommand */
> qemuDomainSetMemoryParameters, /* domainSetMemoryParameters */
> - NULL, /* domainGetMemoryParameters */
> + qemuDomainGetMemoryParameters, /* domainGetMemoryParameters */
> };
Okay, once heavilly patched as described, ACK, I commited this to my tree,
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel at veillard.com | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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