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sysconf params like _SC_LEVEL1_DCACHE_LINESIZE are not universally
implemented, therefore check for them being available, if not there
then read the sysfs directly to get the value
Upstream-Status: Pending
Signed-off-by: Khem Raj <raj.khem@gmail.com>
--- a/src/sat.cc
+++ b/src/sat.cc
@@ -1482,15 +1482,47 @@ int Sat::CpuCount() {
return sysconf(_SC_NPROCESSORS_CONF);
}
+int Sat::ReadInt(const char *filename, int *value) {
+ char line[64];
+ int fd = open(filename, O_RDONLY), err = -1;
+
+ if (fd < 0)
+ return -1;
+ if (read(fd, line, sizeof(line)) > 0) {
+ *value = atoi(line);
+ err = 0;
+ }
+
+ close(fd);
+ return err;
+}
+
// Return the worst case (largest) cache line size of the various levels of
// cache actually prsent in the machine.
int Sat::CacheLineSize() {
- int max_linesize = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
- int linesize = sysconf(_SC_LEVEL2_CACHE_LINESIZE);
+ int max_linesize, linesize;
+#ifdef _SC_LEVEL1_DCACHE_LINESIZE
+ max_linesize = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
+#else
+ ReadInt("/sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size", &max_linesize);
+#endif
+#ifdef _SC_LEVEL2_DCACHE_LINESIZE
+ linesize = sysconf(_SC_LEVEL2_DCACHE_LINESIZE);
+#else
+ ReadInt("/sys/devices/system/cpu/cpu0/cache/index1/coherency_line_size", &linesize);
+#endif
if (linesize > max_linesize) max_linesize = linesize;
- linesize = sysconf(_SC_LEVEL3_CACHE_LINESIZE);
+#ifdef _SC_LEVEL3_DCACHE_LINESIZE
+ linesize = sysconf(_SC_LEVEL3_DCACHE_LINESIZE);
+#else
+ ReadInt("/sys/devices/system/cpu/cpu0/cache/index2/coherency_line_size", &linesize);
+#endif
if (linesize > max_linesize) max_linesize = linesize;
- linesize = sysconf(_SC_LEVEL4_CACHE_LINESIZE);
+#ifdef _SC_LEVEL4_DCACHE_LINESIZE
+ linesize = sysconf(_SC_LEVEL4_DCACHE_LINESIZE);
+#else
+ ReadInt("/sys/devices/system/cpu/cpu0/cache/index3/coherency_line_size", &linesize);
+#endif
if (linesize > max_linesize) max_linesize = linesize;
return max_linesize;
}
--- a/src/sat.h
+++ b/src/sat.h
@@ -136,7 +136,8 @@ class Sat {
int CpuCount();
// Return the worst-case (largest) cache line size of the system.
int CacheLineSize();
-
+ // Read int values from kernel file system e.g. sysfs
+ int ReadInt(const char *filename, int *value);
// Collect error counts from threads.
int64 GetTotalErrorCount();
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