On Fri, Oct 08, 2010 at 05:45:55PM +0530, Nikunj A. Dadhania wrote:
From: Nikunj A. Dadhania <nikunj@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@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@veillard.com | Rpmfind RPM search engine http://rpmfind.net/ http://veillard.com/ | virtualization library http://libvirt.org/