1sysconf params like _SC_LEVEL1_DCACHE_LINESIZE are not universally
2implemented, therefore check for them being available, if not there
3then read the sysfs directly to get the value
4
5Upstream-Status: Pending
6Signed-off-by: Khem Raj <raj.khem@gmail.com>
7--- a/src/sat.cc
8+++ b/src/sat.cc
9@@ -1482,15 +1482,47 @@ int Sat::CpuCount() {
10   return sysconf(_SC_NPROCESSORS_CONF);
11 }
12
13+int Sat::ReadInt(const char *filename, int *value) {
14+  char line[64];
15+  int fd = open(filename, O_RDONLY), err = -1;
16+
17+  if (fd < 0)
18+    return -1;
19+  if (read(fd, line, sizeof(line)) > 0) {
20+    *value = atoi(line);
21+    err = 0;
22+  }
23+
24+  close(fd);
25+  return err;
26+}
27+
28 // Return the worst case (largest) cache line size of the various levels of
29 // cache actually prsent in the machine.
30 int Sat::CacheLineSize() {
31-  int max_linesize = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
32-  int linesize = sysconf(_SC_LEVEL2_CACHE_LINESIZE);
33+  int max_linesize, linesize;
34+#ifdef _SC_LEVEL1_DCACHE_LINESIZE
35+  max_linesize = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
36+#else
37+  ReadInt("/sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size", &max_linesize);
38+#endif
39+#ifdef _SC_LEVEL2_DCACHE_LINESIZE
40+  linesize = sysconf(_SC_LEVEL2_DCACHE_LINESIZE);
41+#else
42+  ReadInt("/sys/devices/system/cpu/cpu0/cache/index1/coherency_line_size", &linesize);
43+#endif
44   if (linesize > max_linesize) max_linesize = linesize;
45-  linesize = sysconf(_SC_LEVEL3_CACHE_LINESIZE);
46+#ifdef _SC_LEVEL3_DCACHE_LINESIZE
47+  linesize = sysconf(_SC_LEVEL3_DCACHE_LINESIZE);
48+#else
49+  ReadInt("/sys/devices/system/cpu/cpu0/cache/index2/coherency_line_size", &linesize);
50+#endif
51   if (linesize > max_linesize) max_linesize = linesize;
52-  linesize = sysconf(_SC_LEVEL4_CACHE_LINESIZE);
53+#ifdef _SC_LEVEL4_DCACHE_LINESIZE
54+  linesize = sysconf(_SC_LEVEL4_DCACHE_LINESIZE);
55+#else
56+  ReadInt("/sys/devices/system/cpu/cpu0/cache/index3/coherency_line_size", &linesize);
57+#endif
58   if (linesize > max_linesize) max_linesize = linesize;
59   return max_linesize;
60 }
61--- a/src/sat.h
62+++ b/src/sat.h
63@@ -136,7 +136,8 @@ class Sat {
64   int CpuCount();
65   // Return the worst-case (largest) cache line size of the system.
66   int CacheLineSize();
67-
68+  // Read int values from kernel file system e.g. sysfs
69+  int ReadInt(const char *filename, int *value);
70   // Collect error counts from threads.
71   int64 GetTotalErrorCount();
72
73