Re: [libvirt PATCH 01/13] util: Helper functions to get process info

These helper methods are used to capture vcpu information in ch driver. Signed-off-by: Vineeth Pillai <viremana(a)linux.microsoft.com&gt; Signed-off-by: Praveen K Paladugu <prapal(a)linux.microsoft.com&gt; --- src/util/virprocess.c | 136 ++++++++++++++++++++++++++++++++++++++++++ src/util/virprocess.h | 5 ++ 2 files changed, 141 insertions(+) diff --git a/src/util/virprocess.c b/src/util/virprocess.c index 6de3f36f52..0164d70df6 100644 --- a/src/util/virprocess.c +++ b/src/util/virprocess.c @@ -1721,3 +1721,139 @@ virProcessSetScheduler(pid_t pid G_GNUC_UNUSED, } #endif /* !WITH_SCHED_SETSCHEDULER */ + +/* +TODO: This method was cloned from qemuGetProcessInfo in src/qemu/qemu_driver.c. +Need to refactor qemu driver to use this shared function. +*/

+int +virProcessGetStatInfo(unsigned long long *cpuTime, int *lastCpu, long *vm_rss, + pid_t pid, pid_t tid) +{ + g_autofree char *proc = NULL; + FILE *pidinfo; + unsigned long long usertime = 0, systime = 0; + long rss = 0; + int cpu = 0; + + /* In general, we cannot assume pid_t fits in int; but /proc parsing + * is specific to Linux where int works fine. */ + if (tid) + proc = g_strdup_printf("/proc/%d/task/%d/stat", (int)pid, tid); + else + proc = g_strdup_printf("/proc/%d/stat", (int)pid); + if (!proc) + return -1; + + pidinfo = fopen(proc, "r"); + + /* See 'man proc' for information about what all these fields are. We're + * only interested in a very few of them */ + if (!pidinfo || + fscanf(pidinfo, + /* pid -> stime */ + "%*d (%*[^)]) %*c %*d %*d %*d %*d %*d %*u %*u %*u %*u %*u %llu %llu" + /* cutime -> endcode */ + "%*d %*d %*d %*d %*d %*d %*u %*u %ld %*u %*u %*u" + /* startstack -> processor */ + "%*u %*u %*u %*u %*u %*u %*u %*u %*u %*u %*d %d", + &usertime, &systime, &rss, &cpu) != 4) { + VIR_WARN("cannot parse process status data"); + } + + /* We got jiffies + * We want nanoseconds + * _SC_CLK_TCK is jiffies per second + * So calculate thus.... + */ + if (cpuTime) + *cpuTime = 1000ull * 1000ull * 1000ull * (usertime + systime) + / (unsigned long long)sysconf(_SC_CLK_TCK); + if (lastCpu) + *lastCpu = cpu; + + if (vm_rss) + *vm_rss = rss * virGetSystemPageSizeKB(); + + + VIR_DEBUG("Got status for %d/%d user=%llu sys=%llu cpu=%d rss=%ld", + (int)pid, tid, usertime, systime, cpu, rss); + + VIR_FORCE_FCLOSE(pidinfo); + + return 0; +} +/* +TODO: This method was cloned from qemuGetSchedInfo in src/qemu/qemu_driver.c. +Need to refactor qemu driver to use this shared function. +*/ +int virProcessGetSchedInfo(unsigned long long *cpuWait, pid_t pid, pid_t tid) +{ + g_autofree char *proc = NULL; + g_autofree char *data = NULL; + char **lines = NULL; + size_t i; + int ret = -1; + double val; + + *cpuWait = 0; + + /* In general, we cannot assume pid_t fits in int; but /proc parsing + * is specific to Linux where int works fine. */ + if (tid) + proc = g_strdup_printf("/proc/%d/task/%d/sched", (int)pid, (int)tid); + else + proc = g_strdup_printf("/proc/%d/sched", (int)pid); + if (!proc) + goto cleanup; + ret = -1; + + /* The file is not guaranteed to exist (needs CONFIG_SCHED_DEBUG) */ + if (access(proc, R_OK) < 0) { + ret = 0; + goto cleanup; + } + + if (virFileReadAll(proc, (1<<16), &data) < 0) + goto cleanup; + + lines = g_strsplit(data, "\n", 0); + if (!lines) + goto cleanup; + + for (i = 0; lines[i] != NULL; i++) { + const char *line = lines[i]; + + /* Needs CONFIG_SCHEDSTATS. The second check + * is the old name the kernel used in past */ + if (STRPREFIX(line, "se.statistics.wait_sum") || + STRPREFIX(line, "se.wait_sum")) { + line = strchr(line, ':'); + if (!line) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Missing separator in sched info '%s'"), + lines[i]); + goto cleanup; + } + line++; + while (*line == ' ') + line++; + + if (virStrToDouble(line, NULL, &val) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Unable to parse sched info value '%s'"), + line); + goto cleanup; + } + + *cpuWait = (unsigned long long)(val * 1000000); + break; + } + } + + ret = 0; + + cleanup: + g_strfreev(lines); + return ret; +} diff --git a/src/util/virprocess.h b/src/util/virprocess.h index 9910331a0c..3a7c4c2d64 100644 --- a/src/util/virprocess.h +++ b/src/util/virprocess.h @@ -127,3 +127,8 @@ typedef enum { } virProcessNamespaceFlags; int virProcessNamespaceAvailable(unsigned int ns); + +int virProcessGetStatInfo(unsigned long long *cpuTime, int *lastCpu, + long *vm_rss, pid_t pid, pid_t tid); +int virProcessGetSchedInfo(unsigned long long *cpuWait, pid_t pid, + pid_t tid);