On 2021/7/27 16:31, Michal Prívozník wrote:
> On 7/22/21 10:05 AM, Yang Fei wrote:
>> Add helper function virHostCPUGetHaltPollTime to obtain halt polling
>> time. If the kernel support halt polling time statistic, and mount
>> debugfs. This function will take effect on KVM VMs.
>>
>> Signed-off-by: Yang Fei <yangfei85@xxxxxxxxxx>
>> ---
>> src/libvirt_private.syms | 1 +
>> src/util/virhostcpu.c | 39 +++++++++++++++++++++++++++++++++++++++
>> src/util/virhostcpu.h | 4 ++++
>> 3 files changed, 44 insertions(+)
>>
>
>> diff --git a/src/util/virhostcpu.c b/src/util/virhostcpu.c
>> index bf7fda23af..7f577c3e3e 100644
>> --- a/src/util/virhostcpu.c
>> +++ b/src/util/virhostcpu.c
>> @@ -1535,3 +1535,42 @@ virHostCPUGetSignature(char **signature)
>> }
>>
>> #endif /* __linux__ */
>> +
>> +int
>> +virHostCPUGetHaltPollTime(pid_t pid,
>> + unsigned long long *haltPollSuccess,
>> + unsigned long long *haltPollFail)
>> +{
>> + g_autofree char *pidToStr = NULL;
>> + g_autofree char *debugFsPath = NULL;
>> + g_autofree char *kvmPath = NULL;
>> + struct dirent *ent = NULL;
>> + g_autoptr(DIR) dir = NULL;
>> + bool found = false;
>> +
>> + if (!(debugFsPath = virFileFindMountPoint("debugfs")))
>> + return -1;
>> +
>> + kvmPath = g_strdup_printf("%s/%s", debugFsPath, "kvm");
>> + if (virDirOpenQuiet(&dir, kvmPath) != 1)
>> + return -1;
>> +
>> + pidToStr = g_strdup_printf("%lld%c", (long long)pid, '-');
>
> Just a tiny nit: this could be "%lld-".
>
Thanks for your review Michal. And do I need to send another version to fix it now?
>> + while (virDirRead(dir, &ent, NULL) > 0) {
>> + if (STRPREFIX(ent->d_name, pidToStr)) {
>> + found = true;
>> + break;
>> + }
>> + }
>> +
>> + if (!found)
>> + return -1;
>> +
>> + if (virFileReadValueUllongQuiet(haltPollSuccess, "%s/%s/%s", kvmPath,
>> + ent->d_name, "halt_poll_success_ns") < 0 ||
>> + virFileReadValueUllongQuiet(haltPollFail, "%s/%s/%s", kvmPath,
>> + ent->d_name, "halt_poll_fail_ns") < 0)
>> + return -1;
>> +
>> + return 0;
>> +}
>
> Michal
>
> .
>
Thanks,
Fei.
