[lttng-dev] Support for large files

Oestman, Fredrik Fredrik_Oestman at mentor.com
Thu Jun 28 04:12:47 EDT 2012


We've run into a problem when attempting to produce large traces on a 32-bit machine. 

This is the console output:

Session met-2012-06-15_16-09-25 created.
Traces will be written in /home/nasir/lttng-traces/met-2012-06-15_16-09-25-20120615-160925
UST channel met_tools enabled for session met-2012-06-15_16-09-25
UST event met_func:* created in channel met_tools
UST event met_call:* created in channel met_tools
Tracing started for session met-2012-06-15_16-09-25
Ackermann: Jun 15 2012 16:01:06
Error: Error writing to tracefile
Tracing stopped for session met-2012-06-15_16-09-25
Session met-2012-06-15_16-09-25 destroyed

This is the trace directory (from another, identical run):

-rwxrwxrwx 1 nasir nasir       4096 2012-06-18 18:38 metadata*
-rwxrwxrwx 1 nasir nasir          0 2012-06-18 18:38 met_tools_0*
-rwxrwxrwx 1 nasir nasir          0 2012-06-18 18:38 met_tools_1*
-rwxrwxrwx 1 nasir nasir 2147483647 2012-06-18 18:40 met_tools_2*
-rwxrwxrwx 1 nasir nasir          0 2012-06-18 18:38 met_tools_3*

That the application runs on one core only is expected. The file size is 2 GiB - 1, which
is the limit for 32-bit file offset variables.

On 64-bit machines, the problem doesn't occur.

Is this problem known?

We are using lttng-ust 2.0.1 and userspace-rcu 0.6.7.


Fredrik Östman

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