On 1/28/22 08:35, huangy81@xxxxxxxxxxxxxxx wrote:
> From: Hyman Huang(黄勇) <huangy81@xxxxxxxxxxxxxxx>
>
> Extend domdirtyrate-calc virsh api with mode option, either
> of these three options "page-sampling,dirty-bitmap,dirty-ring"
> can be specified when calculating dirty page rate.
>
> Signed-off-by: Hyman Huang(黄勇) <huangy81@xxxxxxxxxxxxxxx>
> ---
> docs/manpages/virsh.rst | 7 +++++--
> src/libvirt-domain.c | 12 +++++++++++-
> src/qemu/qemu_driver.c | 24 +++++++++++++++++++++++-
> tools/virsh-domain.c | 28 +++++++++++++++++++++++++++-
> 4 files changed, 66 insertions(+), 5 deletions(-)
These changes need to be broken into smaller patches. Modifying virsh is
one patch, qemu driver is the other.
>
> diff --git a/docs/manpages/virsh.rst b/docs/manpages/virsh.rst
> index e28927e..e09703c 100644
> --- a/docs/manpages/virsh.rst
> +++ b/docs/manpages/virsh.rst
> @@ -1714,13 +1714,16 @@ domdirtyrate-calc
> ::
>
> domdirtyrate-calc <domain> [--seconds <sec>]
> + [{--page-sampling | --dirty-bitmap | --dirty-ring}]
I'm wondering whether we should go with domdirtyrate-calc $dom
--mode=[page-samling|dirty-bitmap|dirty-ring] instead. My reasoning is
that it's more user friendly, IMO. But I don't have strong opinion, your
version is good too.
>
> Calculate an active domain's memory dirty rate which may be expected by
> user in order to decide whether it's proper to be migrated out or not.
> The ``seconds`` parameter can be used to calculate dirty rate in a
> specific time which allows 60s at most now and would be default to 1s
> -if missing. The calculated dirty rate information is available by calling
> -'domstats --dirtyrate'.
> +if missing. These three *--page-sampling, --dirty-bitmap, --dirty-ring*
> +paremeters are mutually exclusive and used to specify calculation mode,
> +*--page-sampling* is the default mode if missing. The calculated dirty
> +rate information is available by calling 'domstats --dirtyrate'.
>
>
> domdisplay
> diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
> index 5912551..4caa740 100644
> --- a/src/libvirt-domain.c
> +++ b/src/libvirt-domain.c
> @@ -13298,7 +13298,7 @@ virDomainGetMessages(virDomainPtr domain,
> * virDomainStartDirtyRateCalc:
> * @domain: a domain object
> * @seconds: specified calculating time in seconds
> - * @flags: extra flags; not used yet, so callers should always pass 0
> + * @flags: bitwise-OR of supported virDomainDirtyRateCalcFlags
> *
> * Calculate the current domain's memory dirty rate in next @seconds.
> * The calculated dirty rate information is available by calling
> @@ -13322,6 +13322,16 @@ virDomainStartDirtyRateCalc(virDomainPtr domain,
>
> virCheckReadOnlyGoto(conn->flags, error);
>
> + VIR_EXCLUSIVE_FLAGS_GOTO(VIR_DOMAIN_DIRTYRATE_MODE_PAGE_SAMPLING,
> + VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_BITMAP,
> + error);
> + VIR_EXCLUSIVE_FLAGS_GOTO(VIR_DOMAIN_DIRTYRATE_MODE_PAGE_SAMPLING,
> + VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_RING,
> + error);
> + VIR_EXCLUSIVE_FLAGS_GOTO(VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_BITMAP,
> + VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_RING,
> + error);
> +
> if (conn->driver->domainStartDirtyRateCalc) {
> int ret;
> ret = conn->driver->domainStartDirtyRateCalc(domain, seconds, flags);
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index cb2af61..5c2f289 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -20651,7 +20651,9 @@ qemuDomainStartDirtyRateCalc(virDomainPtr dom,
> VIR_DOMAIN_DIRTYRATE_CALC_MODE_PAGE_SAMPLING;
> int ret = -1;
>
> - virCheckFlags(0, -1);
> + virCheckFlags(VIR_DOMAIN_DIRTYRATE_MODE_PAGE_SAMPLING |
> + VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_BITMAP |
> + VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_RING, -1);
>
> if (seconds < MIN_DIRTYRATE_CALC_PERIOD ||
> seconds > MAX_DIRTYRATE_CALC_PERIOD) {
> @@ -20687,6 +20689,26 @@ qemuDomainStartDirtyRateCalc(virDomainPtr dom,
> goto endjob;
> }
>
> + if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DIRTYRATE_MODE)) {
> + /* libvirt-domain.c already guaranteed these two flags are exclusive. */
> + if (flags & VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_BITMAP) {
> + mode = VIR_DOMAIN_DIRTYRATE_CALC_MODE_DIRTY_BITMAP;
> + } else if (flags & VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_RING) {
> + if (vm->def->features[VIR_DOMAIN_FEATURE_KVM] != VIR_TRISTATE_SWITCH_ON ||
> + vm->def->kvm_features->features[VIR_DOMAIN_KVM_DIRTY_RING] != VIR_TRISTATE_SWITCH_ON) {
> + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
> + _("dirty-ring calculation mode requires dirty-ring feature enabled."));
> + goto endjob;
> + }
> + mode = VIR_DOMAIN_DIRTYRATE_CALC_MODE_DIRTY_RING;
> + }
> + } else if ((flags & VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_BITMAP ||
> + (flags & VIR_DOMAIN_DIRTYRATE_MODE_DIRTY_RING))) {
> + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
> + _("QEMU does not support dirty page rate calculation mode"));
> + goto endjob;
> + }
> +
Again, this is something that could be done before acquiring domain job.
And if I may suggest slightly different implementation: have the code
that sets @mode first, without checking for qemuCaps and save that bit
for the end:
if (mode != VIR_DOMAIN_DIRTYRATE_MODE_PAGE_SAMPLING &&
virQEMUCapsGet(priv->qemuCaps)) {
error
}
That allows you to drop one level of nesting, which again improves
readability.
> qemuDomainObjEnterMonitor(driver, vm);
> ret = qemuMonitorStartDirtyRateCalc(priv->mon, seconds, mode);
Michal
