[PATCH] blktrace: add timestamp message
This adds a new timestamp message to blktrace, giving the timeofday when
we starting tracing. This helps user space correlate block trace events
with eg an application strace.
This requires a (compatible) update to blkparse. The changed blkparse
is still able to process traces generated by older kernels, and older
versions of blkparse should silently ignore the new records (because
they have a pid of 0).
Signed-off-by: Olaf Kirch <okir@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index b99a714..3680ff9 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -50,6 +50,15 @@
};
/*
+ * Notify events.
+ */
+enum blktrace_notify {
+ __BLK_TN_PROCESS = 0, /* establish pid/name mapping */
+ __BLK_TN_TIMESTAMP, /* include system clock */
+};
+
+
+/*
* Trace actions in full. Additionally, read or write is masked
*/
#define BLK_TA_QUEUE (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
@@ -68,6 +77,9 @@
#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE)
#define BLK_TA_REMAP (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
+#define BLK_TN_PROCESS (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
+#define BLK_TN_TIMESTAMP (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
+
#define BLK_IO_TRACE_MAGIC 0x65617400
#define BLK_IO_TRACE_VERSION 0x07