diff options
Diffstat (limited to 'qga/commands-win32.c')
| -rw-r--r-- | qga/commands-win32.c | 152 |
1 files changed, 148 insertions, 4 deletions
diff --git a/qga/commands-win32.c b/qga/commands-win32.c index 749fdf8..8227480 100644 --- a/qga/commands-win32.c +++ b/qga/commands-win32.c @@ -27,6 +27,7 @@ #include <lm.h> #include <wtsapi32.h> #include <wininet.h> +#include <pdh.h> #include "guest-agent-core.h" #include "vss-win32.h" @@ -119,6 +120,28 @@ static OpenFlags guest_file_open_modes[] = { {"a+b", FILE_GENERIC_APPEND | GENERIC_READ, OPEN_ALWAYS } }; +/* + * We use an exponentially weighted moving average, just like Unix systems do + * https://en.wikipedia.org/wiki/Load_(computing)#Unix-style_load_calculation + * + * These constants serve as the damping factor and are calculated with + * 1 / exp(sampling interval in seconds / window size in seconds) + * + * This formula comes from linux's include/linux/sched/loadavg.h + * https://github.com/torvalds/linux/blob/345671ea0f9258f410eb057b9ced9cefbbe5dc78/include/linux/sched/loadavg.h#L20-L23 + */ +#define LOADAVG_FACTOR_1F 0.9200444146293232478931553241 +#define LOADAVG_FACTOR_5F 0.9834714538216174894737477501 +#define LOADAVG_FACTOR_15F 0.9944598480048967508795473394 +/* + * The time interval in seconds between taking load counts, same as Linux + */ +#define LOADAVG_SAMPLING_INTERVAL 5 + +double load_avg_1m; +double load_avg_5m; +double load_avg_15m; + #define debug_error(msg) do { \ char *suffix = g_win32_error_message(GetLastError()); \ g_debug("%s: %s", (msg), suffix); \ @@ -826,8 +849,6 @@ static void get_disk_properties(HANDLE vol_h, GuestDiskAddress *disk, } out_free: g_free(dev_desc); - - return; } static void get_single_disk_info(int disk_number, @@ -891,7 +912,6 @@ static void get_single_disk_info(int disk_number, err_close: CloseHandle(disk_h); - return; } /* VSS provider works with volumes, thus there is no difference if @@ -2117,7 +2137,6 @@ static void ga_get_win_version(RTL_OSVERSIONINFOEXW *info, Error **errp) rtl_get_version_t rtl_get_version = (rtl_get_version_t)fun; rtl_get_version(info); - return; } static char *ga_get_win_name(const OSVERSIONINFOEXW *os_version, bool id) @@ -2448,3 +2467,128 @@ char *qga_get_host_name(Error **errp) return g_utf16_to_utf8(tmp, size, NULL, NULL, NULL); } + + +static VOID CALLBACK load_avg_callback(PVOID hCounter, BOOLEAN timedOut) +{ + PDH_FMT_COUNTERVALUE displayValue; + double currentLoad; + PDH_STATUS err; + + err = PdhGetFormattedCounterValue( + (PDH_HCOUNTER)hCounter, PDH_FMT_DOUBLE, 0, &displayValue); + /* Skip updating the load if we can't get the value successfully */ + if (err != ERROR_SUCCESS) { + slog("PdhGetFormattedCounterValue failed to get load value with 0x%lx", + err); + return; + } + currentLoad = displayValue.doubleValue; + + load_avg_1m = load_avg_1m * LOADAVG_FACTOR_1F + currentLoad * \ + (1.0 - LOADAVG_FACTOR_1F); + load_avg_5m = load_avg_5m * LOADAVG_FACTOR_5F + currentLoad * \ + (1.0 - LOADAVG_FACTOR_5F); + load_avg_15m = load_avg_15m * LOADAVG_FACTOR_15F + currentLoad * \ + (1.0 - LOADAVG_FACTOR_15F); +} + +static BOOL init_load_avg_counter(Error **errp) +{ + CONST WCHAR *szCounterPath = L"\\System\\Processor Queue Length"; + PDH_STATUS status; + BOOL ret; + HQUERY hQuery; + HCOUNTER hCounter; + HANDLE event; + HANDLE waitHandle; + + status = PdhOpenQueryW(NULL, 0, &hQuery); + if (status != ERROR_SUCCESS) { + /* + * If the function fails, the return value is a system error code or + * a PDH error code. error_setg_win32 cant translate PDH error code + * properly, so just report it as is. + */ + error_setg_win32(errp, (DWORD)status, + "PdhOpenQueryW failed with 0x%lx", status); + return FALSE; + } + + status = PdhAddEnglishCounterW(hQuery, szCounterPath, 0, &hCounter); + if (status != ERROR_SUCCESS) { + error_setg_win32(errp, (DWORD)status, + "PdhAddEnglishCounterW failed with 0x%lx. Performance counters may be disabled.", + status); + PdhCloseQuery(hQuery); + return FALSE; + } + + event = CreateEventW(NULL, FALSE, FALSE, L"LoadUpdateEvent"); + if (event == NULL) { + error_setg_win32(errp, GetLastError(), "Create LoadUpdateEvent failed"); + PdhCloseQuery(hQuery); + return FALSE; + } + + status = PdhCollectQueryDataEx(hQuery, LOADAVG_SAMPLING_INTERVAL, event); + if (status != ERROR_SUCCESS) { + error_setg_win32(errp, (DWORD)status, + "PdhCollectQueryDataEx failed with 0x%lx", status); + CloseHandle(event); + PdhCloseQuery(hQuery); + return FALSE; + } + + ret = RegisterWaitForSingleObject( + &waitHandle, + event, + (WAITORTIMERCALLBACK)load_avg_callback, + (PVOID)hCounter, + INFINITE, + WT_EXECUTEDEFAULT); + + if (ret == 0) { + error_setg_win32(errp, GetLastError(), + "RegisterWaitForSingleObject failed"); + CloseHandle(event); + PdhCloseQuery(hQuery); + return FALSE; + } + + ga_set_load_avg_wait_handle(ga_state, waitHandle); + ga_set_load_avg_event(ga_state, event); + ga_set_load_avg_pdh_query(ga_state, hQuery); + + return TRUE; +} + +GuestLoadAverage *qmp_guest_get_load(Error **errp) +{ + /* + * The load average logic calls PerformaceCounterAPI, which can result + * in a performance penalty. This avoids running the load average logic + * until a management application actually requests it. The load average + * will not initially be very accurate, but assuming that any interested + * management application will request it repeatedly throughout the lifetime + * of the VM, this seems like a good mitigation. + */ + if (ga_get_load_avg_pdh_query(ga_state) == NULL) { + /* set initial values */ + load_avg_1m = 0; + load_avg_5m = 0; + load_avg_15m = 0; + + if (init_load_avg_counter(errp) == false) { + return NULL; + } + } + + GuestLoadAverage *ret = NULL; + + ret = g_new0(GuestLoadAverage, 1); + ret->load1m = load_avg_1m; + ret->load5m = load_avg_5m; + ret->load15m = load_avg_15m; + return ret; +} |