From: compudj <compudj@04897980-b3bd-0310-b5e0-8ef037075253>
Date: Sat, 24 Feb 2007 07:40:46 +0000 (+0000)
Subject: discuss marker types
X-Git-Tag: v0.12.20~1091
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=b82734ba5ce4e6fad74ab36447a560ef48f67c9d;p=lttv.git

discuss marker types

git-svn-id: http://ltt.polymtl.ca/svn@2398 04897980-b3bd-0310-b5e0-8ef037075253
---

diff --git a/ltt/branches/poly/doc/developer/time-monotonic-accurate.txt b/ltt/branches/poly/doc/developer/time-monotonic-accurate.txt
index c1bc89d4..2fb657e4 100644
--- a/ltt/branches/poly/doc/developer/time-monotonic-accurate.txt
+++ b/ltt/branches/poly/doc/developer/time-monotonic-accurate.txt
@@ -84,20 +84,26 @@ wake_from_hlt()
  * This would happen if we are scheduled out for a period of time long enough to
  * permit 2 frequency changes. We simply start the loop again if it happens.
  * We detect it by comparing the update_count running counter. */
+/* FIXME : if thread is migrated to another CPU, get_cycles() is bad */
+/* Pb with get cpu id / migrate / get_cycles() / migrate / get cpu id and check
+ */
 u64 read_time(void)
 {
 	u64 walltime;
 	long update_count;
-	struct time_struct this_cpu_time = 
-		per_cpu(cpu_time, smp_processor_id());
+	struct time_struct this_cpu_time;
 	struct time_info *current_time;
+	unsigned int cpu;
 	do {
+		cpu = _smp_processor_id();
+		this_cpu_time = per_cpu(cpu_time, cpu);
 		update_count = this_cpu_time->update_count;
 		current_time = this_cpu_time->time_sel[update_count&1];
 		walltime = current_time->walltime + 
 				(get_cycles() - current_time->tsc) /
 				current_time->freq;
-	} while(this_cpu_time->update_count != update_count);
+	} while(this_cpu_time->update_count != update_count
+		|| cpu != _smp_processor_id());
 	return walltime;
 }