lttng-ust:stable-2.0

Last commit made on 2013-07-11
Get this branch:
git clone -b stable-2.0 https://git.launchpad.net/lttng-ust

Branch merges

Branch information

Name:
stable-2.0
Repository:
lp:lttng-ust

Recent commits

b93995d... by Mathieu Desnoyers on 2013-07-11

Version 2.0.8

Signed-off-by: Mathieu Desnoyers <email address hidden>

05b3fe3... by Mathieu Desnoyers on 2013-07-03

Fix: ring buffer: get_subbuf() checks should be performed on "consumed" parameter

This triggers lots of false-positive -EAGAIN errors in flight recorder
snapshots.

Reported-by: Julien Desfossez <email address hidden>
Signed-off-by: Mathieu Desnoyers <email address hidden>

643b9dc... by Mathieu Desnoyers on 2013-07-01

Fix: SWITCH_FLUSH new sub-buffer checks

The SWITCH_FLUSH, when performed on a completely empty sub-buffer, was
missing some checks (imported from space reservation).

Signed-off-by: Mathieu Desnoyers <email address hidden>

ad50273... by Mathieu Desnoyers on 2013-07-01

Fix: ring buffer: handle concurrent update in nested buffer wrap around check

With stress-test loads that trigger sub-buffer switch very frequently
(small 4kB sub-buffers, frequent flush) in lttng-modules, we currently
observe this kind of warnings once every few minutes:

[65335.896208] ring buffer relay-overwrite-mmap, cpu 5: records were lost. Caused by:
[65335.896208] [ 0 buffer full, 1 nest buffer wrap-around, 0 event too big ]

It appears that the check for nested buffer wrap-around does not take
into account that a concurrent execution contexts (either nested for
per-cpu buffers, or from another CPU or nested for global buffers) can
update the commit_count value concurrently.

What we really want to do with this check is to ensure that if we enter
a sub-buffer that had an unbalanced reserve/commit count, assuming there
is no hope that this gets rebalanced promptly, we detect this and drop
the current event. However, in the case where the commit counter has
been concurrently updated by another reserve or a switch, we want to
retry the entire reserve operation.

One way to detect this is to sample the reserve offset twice, around the
commit counter read, along with the appropriate memory barriers.
Therefore, we can detect if the mismatch between reserve and commit
counter is actually caused by a concurrent update, which necessarily has
updated the reserve counter.

Signed-off-by: Mathieu Desnoyers <email address hidden>

3ff6e38... by Mathieu Desnoyers on 2013-06-30

Fix: handle writes of length 0

lib_ring_buffer_write() could be passed a length of 0. This typically
has no side-effect as far as writing into the buffers is concerned,
except for one detail: in overwrite mode, there is a check to make sure
the sub-buffer can be written into. This check is performed even if
length is 0. In the case where this would fall exactly at the end of a
sub-buffer, the check would fail, because the offset would fall exactly
at the beginning of the next sub-buffer.

Signed-off-by: Mathieu Desnoyers <email address hidden>

a3c3a9f... by Mathieu Desnoyers on 2013-06-19

Version 2.0.7

Signed-off-by: Mathieu Desnoyers <email address hidden>

2b01008... by Mathieu Desnoyers on 2013-06-19

Fix bug introduced by backport of "Clarify probe registration documentation/errors"

Signed-off-by: Mathieu Desnoyers <email address hidden>

62708e6... by Mathieu Desnoyers on 2013-06-18

Clarify probe registration documentation/errors

Fixes #513

Signed-off-by: Mathieu Desnoyers <email address hidden>

eb00f50... by Mathieu Desnoyers on 2013-06-18

Add mising include in ust.h

Signed-off-by: Mathieu Desnoyers <email address hidden>

69f3425... by Yannick Brosseau on 2013-06-17

lttng-gen-tp: Fix include guard name with file using non valid characters

Now, the include guard will be generated with all the non
alpha-numeric characters replace with an '_'

Fixes #511

Signed-off-by: Yannick Brosseau <email address hidden>
Signed-off-by: Mathieu Desnoyers <email address hidden>