Set the correction factors in the sync_chain

[lttv.git] / lttv / lttv / sync / sync_chain_lttv.c

diff --git a/lttv/lttv/sync/sync_chain_lttv.c b/lttv/lttv/sync/sync_chain_lttv.c
index c0693b7e50d447c2b5d98f61b2e00a25801906a5..0180e3b01a0ee54e1c2c3de64a6eafb66d0120c2 100644 (file)
--- a/lttv/lttv/sync/sync_chain_lttv.c
+++ b/lttv/lttv/sync/sync_chain_lttv.c
@@ -15,12 +15,15 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#define _ISOC99_SOURCE
+
 #ifdef HAVE_CONFIG_H
 #include <config.h>
 #endif
 
 #include <errno.h>
 #include <fcntl.h>
+#include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/resource.h>
@@ -178,6 +181,9 @@ bool syncTraceset(LttvTracesetContext* const traceSetContext)
        struct rusage startUsage, endUsage;
        GList* result;
        unsigned int i;
+       GArray* factors;
+       double minOffset, minDrift;
+       unsigned int refFreqTrace;
        int retval;
 
        if (!optionSync.present)
@@ -262,7 +268,69 @@ bool syncTraceset(LttvTracesetContext* const traceSetContext)
                G_MAXULONG, NULL);
        lttv_process_traceset_seek_time(traceSetContext, ltt_time_zero);
 
-       syncState->processingModule->finalizeProcessing(syncState);
+       // Obtain, adjust and set correction factors
+       factors= syncState->processingModule->finalizeProcessing(syncState);
+
+       /* The offsets are adjusted so the lowest one is 0. This is done because
+        * of a Lttv specific limitation: events cannot have negative times. By
+        * having non-negative offsets, events cannot be moved backwards to
+        * negative times.
+        */
+       minOffset= 0;
+       for (i= 0; i < syncState->traceNb; i++)
+       {
+               minOffset= MIN(g_array_index(factors, Factors, i).offset, minOffset);
+       }
+
+       for (i= 0; i < syncState->traceNb; i++)
+       {
+               g_array_index(factors, Factors, i).offset-= minOffset;
+       }
+
+       /* Because the timestamps are corrected at the TSC level (not at the
+        * LttTime level) all trace frequencies must be made equal. We use the
+        * frequency of the system with the lowest drift
+        */
+       minDrift= INFINITY;
+       refFreqTrace= 0;
+       for (i= 0; i < syncState->traceNb; i++)
+       {
+               if (g_array_index(factors, Factors, i).drift < minDrift)
+               {
+                       minDrift= g_array_index(factors, Factors, i).drift;
+                       refFreqTrace= i;
+               }
+       }
+       g_assert(syncState->traceNb == 0 || minDrift != INFINITY);
+
+       // Write the factors to the LttTrace structures
+       for (i= 0; i < syncState->traceNb; i++)
+       {
+               LttTrace* t;
+               Factors* traceFactors;
+
+               t= traceSetContext->traces[i]->t;
+               traceFactors= &g_array_index(factors, Factors, i);
+
+               t->drift= traceFactors->drift;
+               t->offset= traceFactors->offset;
+               t->start_freq= traceSetContext->traces[refFreqTrace]->t->start_freq;
+               t->freq_scale= traceSetContext->traces[refFreqTrace]->t->freq_scale;
+               t->start_time_from_tsc =
+                       ltt_time_from_uint64(tsc_to_uint64(t->freq_scale, t->start_freq,
+                                       t->drift * t->start_tsc + t->offset));
+       }
+
+       g_array_free(factors, TRUE);
+
+       lttv_traceset_context_compute_time_span(traceSetContext,
+               &traceSetContext->time_span);
+
+       g_debug("traceset start %ld.%09ld end %ld.%09ld",
+               traceSetContext->time_span.start_time.tv_sec,
+               traceSetContext->time_span.start_time.tv_nsec,
+               traceSetContext->time_span.end_time.tv_sec,
+               traceSetContext->time_span.end_time.tv_nsec);
 
        // Write graphs file
        if (!optionSyncNull.present && optionSyncGraphs.present)