hmp-commands-info.hx | 6 +++--- monitor/misc.c | 19 +++++++++++++++++++ 2 files changed, 22 insertions(+), 3 deletions(-)
Originally we have to get all the vCPU registers and parse the
specified one. To improve the performance of this usage, allow user
specified vCPU id to query registers.
Run a VM with 16 vCPU, use bcc tool to track the latency of
'hmp_info_registers':
'info registers -a' uses about 3ms;
'info register 12' uses about 150us.
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
hmp-commands-info.hx | 6 +++---
monitor/misc.c | 19 +++++++++++++++++++
2 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
index 3ffa24bd67..6023e2b5c5 100644
--- a/hmp-commands-info.hx
+++ b/hmp-commands-info.hx
@@ -100,9 +100,9 @@ ERST
{
.name = "registers",
- .args_type = "cpustate_all:-a",
- .params = "[-a]",
- .help = "show the cpu registers (-a: all - show register info for all cpus)",
+ .args_type = "cpustate_all:-a,vcpu:i?",
+ .params = "[-a] [vcpu]",
+ .help = "show the cpu registers (-a: all - show register info for all cpus; vcpu: vCPU to query)",
.cmd = hmp_info_registers,
},
diff --git a/monitor/misc.c b/monitor/misc.c
index 3d2312ba8d..b12309faad 100644
--- a/monitor/misc.c
+++ b/monitor/misc.c
@@ -307,6 +307,7 @@ int monitor_get_cpu_index(Monitor *mon)
static void hmp_info_registers(Monitor *mon, const QDict *qdict)
{
bool all_cpus = qdict_get_try_bool(qdict, "cpustate_all", false);
+ int vcpu = qdict_get_try_int(qdict, "vcpu", -1);
CPUState *cs;
if (all_cpus) {
@@ -314,6 +315,24 @@ static void hmp_info_registers(Monitor *mon, const QDict *qdict)
monitor_printf(mon, "\nCPU#%d\n", cs->cpu_index);
cpu_dump_state(cs, NULL, CPU_DUMP_FPU);
}
+ } else if (vcpu >= 0) {
+ CPUState *target_cs = NULL;
+
+ CPU_FOREACH(cs) {
+ if (cs->cpu_index == vcpu) {
+ target_cs = cs;
+ break;
+ }
+ }
+
+ if (!target_cs) {
+ monitor_printf(mon, "CPU#%d not available\n", vcpu);
+ return;
+ }
+
+ monitor_printf(mon, "\nCPU#%d\n", target_cs->cpu_index);
+ cpu_dump_state(target_cs, NULL, CPU_DUMP_FPU);
+ return;
} else {
cs = mon_get_cpu(mon);
--
2.20.1
On Tuesday, 2022-07-19 at 15:55:44 +08, zhenwei pi wrote: > Originally we have to get all the vCPU registers and parse the > specified one. To improve the performance of this usage, allow user > specified vCPU id to query registers. > > Run a VM with 16 vCPU, use bcc tool to track the latency of > 'hmp_info_registers': > 'info registers -a' uses about 3ms; > 'info register 12' uses about 150us. TYPO: I'm assuming that should be 'info registers 12'? > > Signed-off-by: zhenwei pi <pizhenwei@bytedance.com> > --- > hmp-commands-info.hx | 6 +++--- > monitor/misc.c | 19 +++++++++++++++++++ > 2 files changed, 22 insertions(+), 3 deletions(-) > > diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx > index 3ffa24bd67..6023e2b5c5 100644 > --- a/hmp-commands-info.hx > +++ b/hmp-commands-info.hx > @@ -100,9 +100,9 @@ ERST > > { > .name = "registers", > - .args_type = "cpustate_all:-a", > - .params = "[-a]", > - .help = "show the cpu registers (-a: all - show register info for all cpus)", > + .args_type = "cpustate_all:-a,vcpu:i?", > + .params = "[-a] [vcpu]", From what I can see in the code, only one of these may be specified at a time - or at least, '-a' will take precedence. Maybe it would read more correctly as '[-a|vcpu]' ? > + .help = "show the cpu registers (-a: all - show register info for all cpus; vcpu: vCPU to query)", Possibly also it would be worth saying "...; vcpu: specific vCPU to query"? > .cmd = hmp_info_registers, > }, > > diff --git a/monitor/misc.c b/monitor/misc.c > index 3d2312ba8d..b12309faad 100644 > --- a/monitor/misc.c > +++ b/monitor/misc.c > @@ -307,6 +307,7 @@ int monitor_get_cpu_index(Monitor *mon) > static void hmp_info_registers(Monitor *mon, const QDict *qdict) > { > bool all_cpus = qdict_get_try_bool(qdict, "cpustate_all", false); > + int vcpu = qdict_get_try_int(qdict, "vcpu", -1); > CPUState *cs; > > if (all_cpus) { > @@ -314,6 +315,24 @@ static void hmp_info_registers(Monitor *mon, const QDict *qdict) > monitor_printf(mon, "\nCPU#%d\n", cs->cpu_index); > cpu_dump_state(cs, NULL, CPU_DUMP_FPU); > } > + } else if (vcpu >= 0) { > + CPUState *target_cs = NULL; > + > + CPU_FOREACH(cs) { > + if (cs->cpu_index == vcpu) { > + target_cs = cs; > + break; > + } > + } > + > + if (!target_cs) { > + monitor_printf(mon, "CPU#%d not available\n", vcpu); > + return; > + } > + > + monitor_printf(mon, "\nCPU#%d\n", target_cs->cpu_index); > + cpu_dump_state(target_cs, NULL, CPU_DUMP_FPU); > + return; This return call seems unnecessary here. Thanks, Darren.
PING! On 7/19/22 15:55, zhenwei pi wrote: > Originally we have to get all the vCPU registers and parse the > specified one. To improve the performance of this usage, allow user > specified vCPU id to query registers. > > Run a VM with 16 vCPU, use bcc tool to track the latency of > 'hmp_info_registers': > 'info registers -a' uses about 3ms; > 'info register 12' uses about 150us. > > Signed-off-by: zhenwei pi <pizhenwei@bytedance.com> > --- > hmp-commands-info.hx | 6 +++--- > monitor/misc.c | 19 +++++++++++++++++++ > 2 files changed, 22 insertions(+), 3 deletions(-) > > diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx > index 3ffa24bd67..6023e2b5c5 100644 > --- a/hmp-commands-info.hx > +++ b/hmp-commands-info.hx > @@ -100,9 +100,9 @@ ERST > > { > .name = "registers", > - .args_type = "cpustate_all:-a", > - .params = "[-a]", > - .help = "show the cpu registers (-a: all - show register info for all cpus)", > + .args_type = "cpustate_all:-a,vcpu:i?", > + .params = "[-a] [vcpu]", > + .help = "show the cpu registers (-a: all - show register info for all cpus; vcpu: vCPU to query)", > .cmd = hmp_info_registers, > }, > > diff --git a/monitor/misc.c b/monitor/misc.c > index 3d2312ba8d..b12309faad 100644 > --- a/monitor/misc.c > +++ b/monitor/misc.c > @@ -307,6 +307,7 @@ int monitor_get_cpu_index(Monitor *mon) > static void hmp_info_registers(Monitor *mon, const QDict *qdict) > { > bool all_cpus = qdict_get_try_bool(qdict, "cpustate_all", false); > + int vcpu = qdict_get_try_int(qdict, "vcpu", -1); > CPUState *cs; > > if (all_cpus) { > @@ -314,6 +315,24 @@ static void hmp_info_registers(Monitor *mon, const QDict *qdict) > monitor_printf(mon, "\nCPU#%d\n", cs->cpu_index); > cpu_dump_state(cs, NULL, CPU_DUMP_FPU); > } > + } else if (vcpu >= 0) { > + CPUState *target_cs = NULL; > + > + CPU_FOREACH(cs) { > + if (cs->cpu_index == vcpu) { > + target_cs = cs; > + break; > + } > + } > + > + if (!target_cs) { > + monitor_printf(mon, "CPU#%d not available\n", vcpu); > + return; > + } > + > + monitor_printf(mon, "\nCPU#%d\n", target_cs->cpu_index); > + cpu_dump_state(target_cs, NULL, CPU_DUMP_FPU); > + return; > } else { > cs = mon_get_cpu(mon); > -- zhenwei pi
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