Hi
On Mon, Jul 4, 2022 at 6:42 AM zhenwei pi <pizhen...@bytedance.com> wrote:
> A vCPU thread always reaches 100% utilization when:
> - guest uses idle=poll
> - disable HLT vm-exit
> - enable MWAIT
>
> Add new guest agent command 'guest-get-cpustats' to get guest CPU
> statistics, we can know the guest workload and how busy the CPU is.
>
> Signed-off-by: zhenwei pi <pizhen...@bytedance.com>
> ---
> qga/commands-posix.c | 89 ++++++++++++++++++++++++++++++++++++++++++++
> qga/commands-win32.c | 6 +++
> qga/qapi-schema.json | 81 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 176 insertions(+)
>
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index 0469dc409d..e51f4c8f03 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -2893,6 +2893,90 @@ GuestDiskStatsInfoList
> *qmp_guest_get_diskstats(Error **errp)
> return guest_get_diskstats(errp);
> }
>
> +GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
> +{
> + GuestCpuStatsList *head = NULL, **tail = &head;
> + const char *cpustats = "/proc/stat";
> + int clk_tck = sysconf(_SC_CLK_TCK);
> + FILE *fp;
> + size_t n;
> + char *line = NULL;
> +
> + fp = fopen(cpustats, "r");
> + if (fp == NULL) {
> + error_setg_errno(errp, errno, "open(\"%s\")", cpustats);
> + return NULL;
> + }
> +
> + while (getline(&line, &n, fp) != -1) {
> + GuestCpuStats *cpustat = NULL;
> + GuestLinuxCpuStats *linuxcpustat;
> + int i;
> + unsigned long user, system, idle, iowait, irq, softirq, steal,
> guest;
> + unsigned long nice, guest_nice;
> + char name[64];
> +
> + i = sscanf(line, "%s %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu",
> + name, &user, &nice, &system, &idle, &iowait, &irq,
> &softirq,
> + &steal, &guest, &guest_nice);
> +
> + /* drop "cpu 1 2 3 ...", get "cpuX 1 2 3 ..." only */
> + if ((i == EOF) || strncmp(name, "cpu", 3) || (name[3] == '\0')) {
> + continue;
> + }
> +
> + if (i < 5) {
> + slog("Parsing cpu stat from %s failed, see \"man proc\"",
> cpustats);
> + break;
> + }
> +
> + cpustat = g_new0(GuestCpuStats, 1);
> + cpustat->type = GUEST_OS_TYPE_LINUXOS;
> +
> + linuxcpustat = &cpustat->u.linuxos;
> + linuxcpustat->cpu = atoi(&name[3]);
> + linuxcpustat->user = user * 1000 / clk_tck;
> + linuxcpustat->nice = nice * 1000 / clk_tck;
> + linuxcpustat->system = system * 1000 / clk_tck;
> + linuxcpustat->idle = idle * 1000 / clk_tck;
> +
> + if (i > 5) {
> + linuxcpustat->has_iowait = true;
> + linuxcpustat->iowait = iowait * 1000 / clk_tck;
> + }
> +
> + if (i > 6) {
> + linuxcpustat->has_irq = true;
> + linuxcpustat->irq = irq * 1000 / clk_tck;
> + linuxcpustat->has_softirq = true;
> + linuxcpustat->softirq = softirq * 1000 / clk_tck;
> + }
> +
> + if (i > 8) {
> + linuxcpustat->has_steal = true;
> + linuxcpustat->steal = steal * 1000 / clk_tck;
> + }
> +
> + if (i > 9) {
> + linuxcpustat->has_guest = true;
> + linuxcpustat->guest = guest * 1000 / clk_tck;
> + }
> +
> + if (i > 10) {
> + linuxcpustat->has_guest = true;
> + linuxcpustat->guest = guest * 1000 / clk_tck;
> + linuxcpustat->has_guestnice = true;
> + linuxcpustat->guestnice = guest_nice * 1000 / clk_tck;
> + }
> +
> + QAPI_LIST_APPEND(tail, cpustat);
> + }
> +
> + free(line);
> + fclose(fp);
> + return head;
> +}
> +
> #else /* defined(__linux__) */
>
> void qmp_guest_suspend_disk(Error **errp)
> @@ -3247,6 +3331,11 @@ GuestDiskStatsInfoList
> *qmp_guest_get_diskstats(Error **errp)
> return NULL;
> }
>
> +GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
> +{
> + error_setg(errp, QERR_UNSUPPORTED);
> + return NULL;
> +}
>
> #endif /* CONFIG_FSFREEZE */
>
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index 36f94c0f9c..7ed7664715 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -2543,3 +2543,9 @@ GuestDiskStatsInfoList
> *qmp_guest_get_diskstats(Error **errp)
> error_setg(errp, QERR_UNSUPPORTED);
> return NULL;
> }
> +
> +GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
> +{
> + error_setg(errp, QERR_UNSUPPORTED);
> + return NULL;
> +}
> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
> index 9fa20e791b..3b795222e9 100644
> --- a/qga/qapi-schema.json
> +++ b/qga/qapi-schema.json
> @@ -1576,3 +1576,84 @@
> { 'command': 'guest-get-diskstats',
> 'returns': ['GuestDiskStatsInfo']
> }
> +
> +##
> +# @GuestOsType:
> +#
> +# An enumeration of OS type
> +#
> +# Since: 7.1
> +##
> +{ 'enum': 'GuestOsType',
> + 'data': [ 'linuxos', 'windowsos' ] }
>
I would rather keep this enum specific to GuestCpuStats,
"GuestLinuxCpuStatsType"?
I would also drop the "os" suffix
+
> +
> +##
> +# @GuestLinuxCpuStats:
> +#
> +# CPU statistics of Linux
> +#
> +# @cpu: CPU index in guest OS
> +#
> +# @user: Time spent in user mode
> +#
> +# @nice: Time spent in user mode with low priority (nice)
> +#
> +# @system: Time spent in system mode
> +#
> +# @idle: Time spent in the idle task
> +#
> +# @iowait: Time waiting for I/O to complete (since Linux 2.5.41)
> +#
> +# @irq: Time servicing interrupts (since Linux 2.6.0-test4)
> +#
> +# @softirq: Time servicing softirqs (since Linux 2.6.0-test4)
> +#
> +# @steal: Stolen time by host (since Linux 2.6.11)
> +#
> +# @guest: ime spent running a virtual CPU for guest operating systems
> under
> +# the control of the Linux kernel (since Linux 2.6.24)
> +#
> +# @guestnice: Time spent running a niced guest (since Linux 2.6.33)
> +#
> +# Since: 7.1
> +##
> +{ 'struct': 'GuestLinuxCpuStats',
> + 'data': {'cpu': 'int',
> + 'user': 'uint64',
> + 'nice': 'uint64',
> + 'system': 'uint64',
> + 'idle': 'uint64',
> + '*iowait': 'uint64',
> + '*irq': 'uint64',
> + '*softirq': 'uint64',
> + '*steal': 'uint64',
> + '*guest': 'uint64',
> + '*guestnice': 'uint64'
> + } }
> +
> +##
> +# @GuestCpuStats:
> +#
> +# Get statistics of each CPU in millisecond.
> +#
> +# - @linux: Linux style CPU statistics
> +#
> +# Since: 7.1
> +##
> +{ 'union': 'GuestCpuStats',
> + 'base': { 'type': 'GuestOsType' },
> + 'discriminator': 'type',
> + 'data': { 'linuxos': 'GuestLinuxCpuStats' } }
> +
> +##
> +# @guest-get-cpustats:
> +#
> +# Retrieve information about CPU stats.
> +# Returns: List of CPU stats of guest.
> +#
> +# Since: 7.1
> +##
> +{ 'command': 'guest-get-cpustats',
> + 'returns': ['GuestCpuStats']
> +}
> --
> 2.20.1
>
>
>
Looks good to me otherwise.
thanks
--
Marc-André Lureau
