On 07/10/2014 03:24 PM, Mathieu Desnoyers wrote: > ----- Original Message ----- >> From: "Paul Woegerer" <[email protected]> >> To: [email protected], "mathieu desnoyers" >> <[email protected]> >> Sent: Thursday, July 10, 2014 8:49:37 AM >> Subject: Ping: Re: [PATCH lttng-ust] Bugfix for >> http://bugs.lttng.org/issues/745 >> >> Hi Mathieu, >> >> Since we have no other options currently (see LD_AUDIT discussion) we >> really should get this merged into master. As said, it's thoroughly >> tested and should not cause any ill side-effects. > > Hi Paul, > > Sorry about the delayed answer, I was busy implementing a tool that extracts > UST buffers in the event of a system crash. > > Looking at your patch below, I wonder why you use a semaphore (0, 1) rather > than a mutex ? I guess you could achieve the same result with a pthread > mutex ? If so, it would be better, because it makes it easier to understand > mutex nesting.
Thanks for your feedback. I will build another variant that uses a mutex instead and run it through the same test procedure. If that works equally well I sent an updated patch. -- Paul > > Thanks, > > Mathieu > >> >> Many Thanks, >> Paul >> >> On 07/04/2014 02:21 PM, Paul Woegerer wrote: >>> Since (at least) in the short term LD_AUDIT will not be able to make >>> sem_wait() >>> in the static constructor go away I provide the following patch to fix >>> http://bugs.lttng.org/issues/745. >>> >>> It works by making the process of forking mutual exclusive with base >>> address >>> statedumping that happens from the ust_listener_thread. >>> >>> I have tested this fix with several variations of (constrained) fork bombs >>> (including tests/regression/ust/daemon from lttng-tools) on x86_64, >>> ARM(imx6q) >>> and powerpc(P4080DS). It works reliable. I could not find any issues with >>> this >>> approach. >>> >>> Paul Woegerer (1): >>> Bugfix for #745 deadlock with baddr statedump+fork >>> >>> liblttng-ust/lttng-ust-comm.c | 21 +++++++++++++++++++++ >>> 1 file changed, 21 insertions(+) >>> >> >> >> -- >> Paul Woegerer, SW Development Engineer >> Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer> >> Mentor Graphics, Embedded Software Division >> > -- Paul Woegerer, SW Development Engineer Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer> Mentor Graphics, Embedded Software Division _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
