[PATCH v2 3/3] ntdll: Implement NtQuerySystemInformationEx( SystemProcessorIdleCycleTimeInformation ) on Linux.

[Paul Gofman]

From: Paul Gofman

---
 dlls/ntdll/unix/system.c | 76 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 74 insertions(+), 2 deletions(-)

diff --git a/dlls/ntdll/unix/system.c b/dlls/ntdll/unix/system.c
index 7eba7ecdbf9..f87c9b09124 100644
--- a/dlls/ntdll/unix/system.c
+++ b/dlls/ntdll/unix/system.c
@@ -228,6 +228,7 @@ static SYSTEM_LOGICAL_PROCESSOR_INFORMATION *logical_proc_info;
 static unsigned int logical_proc_info_len, logical_proc_info_alloc_len;
 static SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX *logical_proc_info_ex;
 static unsigned int logical_proc_info_ex_size, logical_proc_info_ex_alloc_size;
+static ULONG_PTR system_cpu_mask;

static pthread_mutex_t timezone_mutex = PTHREAD_MUTEX_INITIALIZER;

@@ -835,6 +836,7 @@ static BOOL logical_proc_info_add_group( DWORD num_cpus, ULONG_PTR mask )
     dataex->Group.GroupInfo[0].ActiveProcessorMask = mask;

logical_proc_info_ex_size += dataex->Size;
+    system_cpu_mask |= mask;
     return TRUE;
 }

@@ -1278,6 +1280,35 @@ static NTSTATUS create_logical_proc_info(void)
 }
 #endif

+#ifdef linux
+
+static double tsc_from_jiffies[MAXIMUM_PROCESSORS];
+
+static void init_tsc_frequency(void)
+{
+    unsigned long clk_tck = sysconf( _SC_CLK_TCK );
+    char filename[128];
+    unsigned long val;
+    unsigned int i;
+    FILE *f;
+
+    for (i = 0; i < MAXIMUM_PROCESSORS; ++i)
+    {
+        if (system_cpu_mask && !(system_cpu_mask & ((ULONG_PTR)1 << i))) continue;
+        snprintf( filename, sizeof(filename), "/sys/devices/system/cpu/cpu%d/cpufreq/base_frequency", i );
+        if (!(f = fopen( filename, "r" ))) break;
+        if (fscanf( f, "%lu", &val ) == 1) tsc_from_jiffies[i] = 1000.0 * val / clk_tck;
+        fclose( f );
+    }
+}
+#else
+
+static void init_tsc_frequency(void)
+{
+}
+
+#endif
+
 /******************************************************************
  *		init_cpu_info
  *
@@ -1336,6 +1367,7 @@ void init_cpu_info(void)
         logical_proc_info_ex = realloc( logical_proc_info_ex, logical_proc_info_ex_size );
         logical_proc_info_ex_alloc_size = logical_proc_info_ex_size;
     }
+    init_tsc_frequency();
 }

static NTSTATUS create_cpuset_info(SYSTEM_CPU_SET_INFORMATION *info)
@@ -2124,6 +2156,47 @@ static void get_performance_info( SYSTEM_PERFORMANCE_INFORMATION *info )
     info->TotalCommitLimit    = (totalram + totalswap) / page_size;
 }

+#ifdef linux
+
+static void get_cpu_idle_cycle_times( ULONG64 *times )
+{
+    unsigned int index, host_index, count;
+    char line[256], name[32];
+    unsigned long long idle;
+    FILE *f;
+
+    memset( times, 0, peb->NumberOfProcessors * sizeof(*times) );
+    if (!(f = fopen( "/proc/stat", "r" ))) return;
+
+    /* skip combined cpu statistics line. */
+    fgets( line, sizeof(line), f );
+
+    index = 0;
+    while (fgets( line, sizeof(line), f ) && index < peb->NumberOfProcessors)
+    {
+        count = sscanf(line, "%s %*u %*u %*u %llu", name, &idle);
+
+        if (count < 2 || strncmp( name, "cpu", 3 )) break;
+        host_index = atoi( name + 3 );
+        if (system_cpu_mask && !(system_cpu_mask & ((ULONG_PTR)1 << host_index))) continue;
+        times[index] = idle * tsc_from_jiffies[host_index];
+        ++index;
+    }
+
+    fclose( f );
+}
+#else
+
+static void get_cpu_idle_cycle_times( ULONG64 *times )
+{
+    static int once;
+
+    if (!once++) FIXME( "SystemProcessorIdleCycleTimeInformation stub.\n" );
+    memset( times, 0, peb->NumberOfProcessors * sizeof(*times) );
+}
+
+#endif
+

/* calculate the mday of dst change date, so that for instance Sun 5 Oct 2007
  * (last Sunday in October of 2007) becomes Sun Oct 28 2007
@@ -3422,8 +3495,7 @@ NTSTATUS WINAPI NtQuerySystemInformationEx( SYSTEM_INFORMATION_CLASS class,
             ret = STATUS_BUFFER_TOO_SMALL;
             break;
         }
-        FIXME( "SystemProcessorIdleCycleTimeInformation stub.\n" );
-        memset( info, 0, len );
+        get_cpu_idle_cycle_times( info );
         ret = STATUS_SUCCESS;
         break;