On Thu, Nov 13, 2014 at 12:11 AM, Julien Desfossez <[email protected]> wrote:
> Hi, > > On 14-11-12 05:30 PM, Jérémie Galarneau wrote: > > On Wed, Nov 12, 2014 at 7:39 AM, Anders Wallin <[email protected]> > wrote: > >> Hi, > >> > >> using userspace snapshot mode in 2.5 seems to broken. > >> > >> I have small stupid application(tracetest) generating 1000 events > >> > >> Running the script (the below is simplified version of the script) > >> > ---------------------------------------------------------------------------------- > >> #!/bin/bash > >> LTTNG='lttng -n' > >> lttng-sessiond --no-kernel & > > > > You should use the "-d" flag to launch the sessiond as a daemon. Using > > "&" might cause the "create" command to launch a second session daemon > > since the first one would not have had the time to open create its > > command sockets. > > > >> > >> $LTTNG create test --snapshot > >> $LTTNG enable-channel -u --subbuf-size 64k --num-subbuf 16 --overwrite > ch1 > >> $LTTNG enable-event -u -c ch1 "*" > >> $LTTNG start > >> $LTTNG list ch1 > >> > >> mkdir -p snapshot/ > >> > >> for i in $(seq 1 $LOOPS); do > >> ./tracetest > >> $LTTNG snapshot record -m 1G > >> > >> # print no of events and first and last event > >> last=$(ls -1drt $HOME/lttng-traces/$SESSION*/* | tail -1) > >> babeltrace $last > snapshot/$i.bt > >> cat snapshot/$i.bt | wc -l > >> cat snapshot/$i.bt | head -1 > >> cat snapshot/$i.bt | tail -1 > >> done > >> > >> $LTTNG stop > >> $LTTNG destroy $SESSION > >> > ---------------------------------------------------------------------------------- > >> > >> The result of the run looks like this; > >> ./test.run > >> Error: consumer err socket second poll error > >> Error: Health error occurred in thread_manage_consumer > >> PERROR - 13:36:59.685167 [23772/23781]: bind inet: Address already in > use > >> (in lttcomm_bind_inet_sock() at inet.c:109) > >> Warning: Another session daemon is using this JUL port. JUL support > will be > >> deactivated to prevent interfering with the tracing. > >> > > > > Is there a reason why you run two session daemons? I'm guessing this > > is related to my "& vs -d" comment above. > > > >> lttng (LTTng Trace Control) 2.5.2 - Fumisterie > >> BabelTrace Trace Viewer and Converter 1.2.4 > >> linux-vdso.so.1 => (0x00007fffba966000) > >> liblttng-ctl.so.0 => /usr/lib/x86_64-linux-gnu/liblttng-ctl.so.0 > >> (0x00007fbfe4b1d000) > >> librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 > (0x00007fbfe4915000) > >> libxml2.so.2 => /usr/lib/x86_64-linux-gnu/libxml2.so.2 > >> (0x00007fbfe45ae000) > >> libpopt.so.0 => /lib/x86_64-linux-gnu/libpopt.so.0 > >> (0x00007fbfe43a2000) > >> libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 > >> (0x00007fbfe4184000) > >> libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 > (0x00007fbfe3dbd000) > >> /lib64/ld-linux-x86-64.so.2 (0x00007fbfe4fac000) > >> liburcu.so.2 => /usr/lib/x86_64-linux-gnu/liburcu.so.2 > >> (0x00007fbfe3bb6000) > >> libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 > (0x00007fbfe39b2000) > >> libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 > (0x00007fbfe3798000) > >> liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 > >> (0x00007fbfe3576000) > >> libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 > (0x00007fbfe3270000) > >> > >> Session test created. > >> Default snapshot output set to: > >> /home/awallin/lttng-traces/test-20141112-133700 > >> Snapshot mode set. Every channel enabled for that session will be set in > >> overwrite mode and mmap output. > >> UST channel ch1 enabled for session test > >> UST event * created in channel ch1 > >> Tracing started for session test > >> Tracing session test: [active snapshot] > >> Trace path: > >> Live timer interval (usec): 4294967295 > >> > >> === Domain: UST global === > >> > >> Channels: > >> ------------- > >> - ch1: [enabled] > >> > >> Attributes: > >> overwrite mode: 1 > >> subbufers size: 4096 > >> number of subbufers: 16 > >> switch timer interval: 0 > >> read timer interval: 0 > >> trace file count: 0 > >> trace file size (bytes): 0 > >> output: mmap() > >> > >> Events: > >> * (type: tracepoint) [enabled] > >> > >> Snapshot recorded successfully for session test > >> 84 > >> [13:37:00.852615950] (+?.?????????) arn-awallin-mint-l3 > >> ust_baddr_statedump:soinfo: { cpu_id = 4 }, { baddr = 0x7FFFC6BC7000, > sopath > >> = "[vdso]", size = 0, mtime = -1 } > >> [13:37:00.853798949] (+0.000000805) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 6 }, { my_string_field = "test", my_integer_field = 999 } > >> Snapshot recorded successfully for session test > >> 157 > >> [13:37:00.853735195] (+?.?????????) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 6 }, { my_string_field = "test", my_integer_field = 927 } > >> [13:37:00.894839116] (+0.000000299) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 5 }, { my_string_field = "test", my_integer_field = 999 } > >> Snapshot recorded successfully for session test > >> 168 > >> [13:37:00.853735195] (+?.?????????) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 6 }, { my_string_field = "test", my_integer_field = 927 } > >> [13:37:00.929447330] (+0.000000305) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 5 }, { my_string_field = "test", my_integer_field = 999 } > >> Snapshot recorded successfully for session test > > Something is wrong from here: > >> 168 > >> [13:37:00.894411117] (+?.?????????) arn-awallin-mint-l3 > >> ust_baddr_statedump:soinfo: { cpu_id = 4 }, { baddr = 0x7FFF6BF81000, > sopath > >> = "[vdso]", size = 0, mtime = -1 } > >> [13:37:00.972035546] (+0.000000597) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 6 }, { my_string_field = "test", my_integer_field = 999 } > >> Snapshot recorded successfully for session test > >> 168 > >> [13:37:00.894411117] (+?.?????????) arn-awallin-mint-l3 > >> ust_baddr_statedump:soinfo: { cpu_id = 4 }, { baddr = 0x7FFF6BF81000, > sopath > >> = "[vdso]", size = 0, mtime = -1 } > >> [13:37:01.014060940] (+0.000000341) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 7 }, { my_string_field = "test", my_integer_field = 999 } > >> Snapshot recorded successfully for session test > >> 168 > >> [13:37:00.894411117] (+?.?????????) arn-awallin-mint-l3 > >> ust_baddr_statedump:soinfo: { cpu_id = 4 }, { baddr = 0x7FFF6BF81000, > sopath > >> = "[vdso]", size = 0, mtime = -1 } > >> [13:37:01.052555877] (+0.000000872) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 6 }, { my_string_field = "test", my_integer_field = 999 } > ... to here. > > The beginning timestamp is the same, the number of events is the same, > but the end timestamp moves. We see also this pattern below. > I would be really interested to see the whole snapshots when it happens. > It seems like we are not be overwriting the beginning of the ring buffer > in some conditions. Could you send us your tracetest program and the > script so we can try to reproduce the problem ? > I will append it including a run with debug turned on and all the snapshot files created > > >> Snapshot recorded successfully for session test > >> 168 > >> [13:37:01.014035993] (+?.?????????) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 7 }, { my_string_field = "test", my_integer_field = 927 } > >> [13:37:01.098620808] (+0.000001404) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 4 }, { my_string_field = "test", my_integer_field = 999 } > >> Snapshot recorded successfully for session test > >> 168 > >> [13:37:01.097087388] (+?.?????????) arn-awallin-mint-l3 > >> ust_baddr_statedump:soinfo: { cpu_id = 6 }, { baddr = 0x7FFF4BFFE000, > sopath > >> = "[vdso]", size = 0, mtime = -1 } > >> [13:37:01.129839830] (+0.000000533) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 7 }, { my_string_field = "test", my_integer_field = 999 } > >> Snapshot recorded successfully for session test > >> 168 > >> [13:37:01.097087388] (+?.?????????) arn-awallin-mint-l3 > >> ust_baddr_statedump:soinfo: { cpu_id = 6 }, { baddr = 0x7FFF4BFFE000, > sopath > >> = "[vdso]", size = 0, mtime = -1 } > >> [13:37:01.129839830] (+0.000000533) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 7 }, { my_string_field = "test", my_integer_field = 999 } > >> Snapshot recorded successfully for session test > >> 168 > >> [13:37:01.097087388] (+?.?????????) arn-awallin-mint-l3 > >> ust_baddr_statedump:soinfo: { cpu_id = 6 }, { baddr = 0x7FFF4BFFE000, > sopath > >> = "[vdso]", size = 0, mtime = -1 } > >> [13:37:01.172829105] (+0.000000575) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 5 }, { my_string_field = "test", my_integer_field = 999 } > >> Snapshot recorded successfully for session test > >> 168 > >> [13:37:01.172021557] (+?.?????????) arn-awallin-mint-l3 > >> ust_baddr_statedump:soinfo: { cpu_id = 7 }, { baddr = 0x7FFF653FE000, > sopath > >> = "[vdso]", size = 0, mtime = -1 } > >> [13:37:01.220074165] (+0.000000553) arn-awallin-mint-l3 > tracetest:first_tp: > >> { cpu_id = 6 }, { my_string_field = "test", my_integer_field = 999 } > >> Waiting for data availability > >> Tracing stopped for session test > >> Session test destroyed > >> > >> the result from the run on older versions of lttng creates bigger and > bigger > >> event traces until reaching max size. > We see this pattern here and the max size seems to be 168 events, was it > similar in your previous tests ? > If I'm running the same test on 2.4 or 2.3 the max number of events is much bigger, like ~10000 (I don't have the exact number right now, I will rebuild and run the test again and get back with traces from that run) > > > > > Unless I'm mistaken, the behavior of the snapshot mode has changed > > between 2.4 and 2.5. > > > > In the 2.4 series, consecutive snapshots could overlap; that is, > > events could be present in multiple snapshots. As of 2.5, an event is > > guaranteed to only appear in one snapshot as the events are considered > > as having been "consumed" at that point. > > Hum, no the behavior is still the same, consecutive snapshots can overlap. > > Could you tell us on which architecture you are experiencing the problem > and the number of CPUs ? > The traces appended is from my laptop running Ubuntu 14.04 with "8" cpu's model name : Intel(R) Core(TM) i7-2760QM CPU @ 2.40GHz I have also run this on ARM with 16 cores and a powerpc > > Thanks, > > Julien >
lttng_ust_test.tgz
Description: GNU Zip compressed data
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