Re: [libvirt] [PATCHv4 4/4] blkiotune: add qemu support for blkiotune.device_weight

From: Hu Tao <hutao(a)cn.fujitsu.com&gt; Implement setting/getting per-device blkio weights in qemu, using the cgroups blkio.weight_device tunable. --- src/libvirt_private.syms | 1 + src/qemu/qemu_cgroup.c | 20 ++ src/qemu/qemu_driver.c | 218 +++++++++++++++++++- src/util/cgroup.c | 51 +++++ src/util/cgroup.h | 4 + .../qemuxml2argv-blkiotune-device.args | 4 + tests/qemuxml2argvtest.c | 1 + tests/qemuxml2xmltest.c | 1 + 8 files changed, 295 insertions(+), 5 deletions(-) create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-blkiotune-device.args diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index d78fd53..3575fe0 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -89,6 +89,7 @@ virCgroupKillRecursive; virCgroupMounted; virCgroupPathOfController; virCgroupRemove; +virCgroupSetBlkioDeviceWeight; virCgroupSetBlkioWeight; virCgroupSetCpuShares; virCgroupSetCpuCfsPeriod; diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c index 2a10bd2..eda4c66 100644 --- a/src/qemu/qemu_cgroup.c +++ b/src/qemu/qemu_cgroup.c @@ -312,6 +312,26 @@ int qemuSetupCgroup(struct qemud_driver *driver, } } + if (vm->def->blkio.ndevices) { + if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_BLKIO)) { + for (i = 0; i < vm->def->blkio.ndevices; i++) { + virBlkioDeviceWeightPtr dw = &vm->def->blkio.devices[i]; + rc = virCgroupSetBlkioDeviceWeight(cgroup, dw->path, + dw->weight); + if (rc != 0) { + virReportSystemError(-rc, + _("Unable to set io device weight " + "for domain %s"), + vm->def->name); + goto cleanup; + } + } + } else { + qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Block I/O tuning is not available on this host")); + } + } + if (vm->def->mem.hard_limit != 0 || vm->def->mem.soft_limit != 0 || vm->def->mem.swap_hard_limit != 0) { diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index b0ce115..43f4041 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -112,7 +112,7 @@ # define KVM_CAP_NR_VCPUS 9 /* returns max vcpus per vm */ #endif -#define QEMU_NB_BLKIO_PARAM 1 +#define QEMU_NB_BLKIO_PARAM 2 static void processWatchdogEvent(void *data, void *opaque); @@ -5885,6 +5885,105 @@ cleanup: return ret; } +/* deviceWeightStr in the form of /device/path,weight,/device/path,weight + * for example, /dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0,800 + */ +static int +parseBlkioWeightDeviceStr(char *deviceWeightStr, + virBlkioDeviceWeightPtr *dw, int *size, + virCgroupPtr cgroup) +{ + char *temp; + int ndevices = 0; + int nsep = 0; + int i; + virBlkioDeviceWeightPtr result = NULL; + + temp = deviceWeightStr; + while (temp) { + temp = strchr(temp, ','); + if (temp) { + temp++; + nsep++; + } + } + + /* A valid string must have even number of fields, hence an odd + * number of commas. */ + if (!(nsep & 1)) + goto error; + + ndevices = (nsep + 1) / 2; + + if (VIR_ALLOC_N(result, ndevices) < 0) { + virReportOOMError(); + return -1; + } + + i = 0; + temp = deviceWeightStr; + while (temp) { + char *p = temp; + + /* device path */ + p = strchr(p, ','); + if (!p) + goto error; + + result[i].path = strndup(temp, p - temp); + if (!result[i].path) { + virReportOOMError(); + goto cleanup; + } + + /* weight */ + temp = p + 1; + + if (virStrToLong_ui(temp, &p, 10, &result[i].weight) < 0) + goto error; + + if (cgroup) { + int rc = virCgroupSetBlkioDeviceWeight(cgroup, + result[i].path, + result[i].weight);