[PATCH v3 1/2] util: Add virGetCpuHaltPollTime
Add helper function virGetCpuHaltPollTime 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(a)huawei.com>
---
src/libvirt_private.syms | 1 +
src/util/virutil.c | 43 ++++++++++++++++++++++++++++++++++++++++
src/util/virutil.h | 4 ++++
3 files changed, 48 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 68e4b6aab8..64aff4eca4 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -3479,6 +3479,7 @@ virDoesUserExist;
virDoubleToStr;
virFormatIntDecimal;
virFormatIntPretty;
+virGetCpuHaltPollTime;
virGetDeviceID;
virGetDeviceUnprivSGIO;
virGetGroupID;
diff --git a/src/util/virutil.c b/src/util/virutil.c
index 311cbbf93a..f5304644c0 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -1936,3 +1936,46 @@ virPipeNonBlock(int fds[2])
{
return virPipeImpl(fds, true, true);
}
+
+int
+virGetCpuHaltPollTime(pid_t pid,
+ unsigned long long *haltPollSuccess,
+ unsigned long long *haltPollFail)
+{
+ g_autofree char *pidToStr = NULL;
+ g_autofree char *debugFsPath = NULL;
+ g_autofree char *completePath = NULL;
+ struct dirent *ent = NULL;
+ g_autoptr(DIR) dir = NULL;
+ int ret = -1;
+ bool found = false;
+
+ if (!(debugFsPath = virFileFindMountPoint("debugfs")))
+ return ret;
+
+ completePath = g_strdup_printf("%s/%s", debugFsPath, "kvm");
+ if (virDirOpenIfExists(&dir, completePath) != 1)
+ return ret;
+
+ pidToStr = g_strdup_printf("%d%c", pid, '-');
+ while (virDirRead(dir, &ent, NULL) > 0) {
+ if (STRPREFIX(ent->d_name, pidToStr)) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ return ret;
+
+ if (virFileReadValueUllong(haltPollSuccess, "%s/%s/%s", completePath,
+ ent->d_name, "halt_poll_success_ns") < 0
+ || virFileReadValueUllong(haltPollFail, "%s/%s/%s", completePath,
+ ent->d_name, "halt_poll_fail_ns") < 0)
{
+ return ret;
+ }
+
+ ret = 0;
+
+ return ret;
+}
diff --git a/src/util/virutil.h b/src/util/virutil.h
index 854b494890..03b225185f 100644
--- a/src/util/virutil.h
+++ b/src/util/virutil.h
@@ -225,3 +225,7 @@ int virPipeQuiet(int fds[2]);
* Returns: -1 on error, 0 on success
*/
int virPipeNonBlock(int fds[2]);
+
+int virGetCpuHaltPollTime(pid_t pid,
+ unsigned long long *haltPollSuccess,
+ unsigned long long *haltPollFail);
--
2.23.0