From 172d34298f202d7af3fd7ef3bd0f061020dcb1c8 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Fri, 10 Feb 2012 14:53:49 -0700 Subject: [PATCH] qemu: make block io tuning smarter When blkdeviotune was first committed in 0.9.8, we had the limitation that setting one value reset all others. But bytes and iops should be relatively independent. Furthermore, setting tuning values on a live domain followed by dumpxml did not output the new settings. * src/qemu/qemu_driver.c (qemuDiskPathToAlias): Add parameter, and update callers. (qemuDomainSetBlockIoTune): Don't lose previous unrelated settings. Make live changes reflect to dumpxml output. * tools/virsh.pod (blkdeviotune): Update documentation. --- src/qemu/qemu_driver.c | 45 ++++++++++++++++++++++++++++++++++++++---- tools/virsh.pod | 5 +++-- 2 files changed, 44 insertions(+), 6 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 160cb37efb..e2e73b7f88 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -11309,7 +11309,7 @@ cleanup: } static char * -qemuDiskPathToAlias(virDomainObjPtr vm, const char *path) +qemuDiskPathToAlias(virDomainObjPtr vm, const char *path, int *idx) { int i; char *ret = NULL; @@ -11320,6 +11320,8 @@ qemuDiskPathToAlias(virDomainObjPtr vm, const char *path) goto cleanup; disk = vm->def->disks[i]; + if (idx) + *idx = i; if (disk->type != VIR_DOMAIN_DISK_TYPE_BLOCK && disk->type != VIR_DOMAIN_DISK_TYPE_FILE) @@ -11361,7 +11363,7 @@ qemuDomainBlockJobImpl(virDomainPtr dom, const char *path, const char *base, goto cleanup; } - device = qemuDiskPathToAlias(vm, path); + device = qemuDiskPathToAlias(vm, path, NULL); if (!device) { goto cleanup; } @@ -11529,11 +11531,14 @@ qemuDomainSetBlockIoTune(virDomainPtr dom, qemuDomainObjPrivatePtr priv; virDomainDefPtr persistentDef = NULL; virDomainBlockIoTuneInfo info; + virDomainBlockIoTuneInfo *oldinfo; char uuidstr[VIR_UUID_STRING_BUFLEN]; const char *device = NULL; int ret = -1; int i; int idx = -1; + bool set_bytes = false; + bool set_iops = false; virCheckFlags(VIR_DOMAIN_AFFECT_LIVE | VIR_DOMAIN_AFFECT_CONFIG, -1); @@ -11564,7 +11569,7 @@ qemuDomainSetBlockIoTune(virDomainPtr dom, goto cleanup; } - device = qemuDiskPathToAlias(vm, disk); + device = qemuDiskPathToAlias(vm, disk, &idx); if (!device) { goto cleanup; } @@ -11581,21 +11586,27 @@ qemuDomainSetBlockIoTune(virDomainPtr dom, if (STREQ(param->field, VIR_DOMAIN_BLOCK_IOTUNE_TOTAL_BYTES_SEC)) { info.total_bytes_sec = param->value.ul; + set_bytes = true; } else if (STREQ(param->field, VIR_DOMAIN_BLOCK_IOTUNE_READ_BYTES_SEC)) { info.read_bytes_sec = param->value.ul; + set_bytes = true; } else if (STREQ(param->field, VIR_DOMAIN_BLOCK_IOTUNE_WRITE_BYTES_SEC)) { info.write_bytes_sec = param->value.ul; + set_bytes = true; } else if (STREQ(param->field, VIR_DOMAIN_BLOCK_IOTUNE_TOTAL_IOPS_SEC)) { info.total_iops_sec = param->value.ul; + set_iops = true; } else if (STREQ(param->field, VIR_DOMAIN_BLOCK_IOTUNE_READ_IOPS_SEC)) { info.read_iops_sec = param->value.ul; + set_iops = true; } else if (STREQ(param->field, VIR_DOMAIN_BLOCK_IOTUNE_WRITE_IOPS_SEC)) { info.write_iops_sec = param->value.ul; + set_iops = true; } } @@ -11614,10 +11625,25 @@ qemuDomainSetBlockIoTune(virDomainPtr dom, } if (flags & VIR_DOMAIN_AFFECT_LIVE) { + /* If the user didn't specify bytes limits, inherit previous + * values; likewise if the user didn't specify iops + * limits. */ + oldinfo = &vm->def->disks[idx]->blkdeviotune; + if (!set_bytes) { + info.total_bytes_sec = oldinfo->total_bytes_sec; + info.read_bytes_sec = oldinfo->read_bytes_sec; + info.write_bytes_sec = oldinfo->write_bytes_sec; + } + if (!set_iops) { + info.total_iops_sec = oldinfo->total_iops_sec; + info.read_iops_sec = oldinfo->read_iops_sec; + info.write_iops_sec = oldinfo->write_iops_sec; + } priv = vm->privateData; qemuDomainObjEnterMonitorWithDriver(driver, vm); ret = qemuMonitorSetBlockIoThrottle(priv->mon, device, &info); qemuDomainObjExitMonitorWithDriver(driver, vm); + vm->def->disks[idx]->blkdeviotune = info; if (ret < 0) goto endjob; } @@ -11627,6 +11653,17 @@ qemuDomainSetBlockIoTune(virDomainPtr dom, idx = virDomainDiskIndexByName(persistentDef, disk, true); if (idx < 0) goto endjob; + oldinfo = &persistentDef->disks[idx]->blkdeviotune; + if (!set_bytes) { + info.total_bytes_sec = oldinfo->total_bytes_sec; + info.read_bytes_sec = oldinfo->read_bytes_sec; + info.write_bytes_sec = oldinfo->write_bytes_sec; + } + if (!set_iops) { + info.total_iops_sec = oldinfo->total_iops_sec; + info.read_iops_sec = oldinfo->read_iops_sec; + info.write_iops_sec = oldinfo->write_iops_sec; + } persistentDef->disks[idx]->blkdeviotune = info; ret = virDomainSaveConfig(driver->configDir, persistentDef); if (ret < 0) { @@ -11688,7 +11725,7 @@ qemuDomainGetBlockIoTune(virDomainPtr dom, goto cleanup; } - device = qemuDiskPathToAlias(vm, disk); + device = qemuDiskPathToAlias(vm, disk, NULL); if (!device) { goto cleanup; diff --git a/tools/virsh.pod b/tools/virsh.pod index 877533bc2a..6730b8b7bb 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -604,8 +604,9 @@ I<--total_iops_sec> specifies total I/O operations limit per second. I<--read_iops_sec> specifies read I/O operations limit per second. I<--write_iops_sec> specifies write I/O operations limit per second. -When setting any value, all remaining values are reset to unlimited, -an explicit 0 also clears any limit. A non-zero value for a given total +Bytes and iops values are independent, but setting only one value (such +as --read_bytes_sec) resets the other two in that category to unlimited. +An explicit 0 also clears any limit. A non-zero value for a given total cannot be mixed with non-zero values for read or write. If I<--live> is specified, affect a running guest.