----- Original Message ----- > From: "Simon Marchi" <simon.mar...@polymtl.ca> > To: lttng-dev@lists.lttng.org > Sent: Friday, December 6, 2013 10:17:55 PM > Subject: [lttng-dev] [PATCH userspace-rcu] Set RCU_HAVE_FENCE to false on > Intel Xeon Phi > > It currently fails to compile, because the Phi does not have fence > instructions. > > It will use lock prefixed instructions for all memory barriers, which > is overkill for this platform, but at least it will work.
Merged. It's overkill, but at least it will compile. We'll see if we want to improve the memory barriers and make them cheaper as an optimization. Thanks, Mathieu > > Signed-off-by: Simon Marchi <simon.mar...@polymtl.ca> > --- > configure.ac | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/configure.ac b/configure.ac > index 774094e..079c145 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -140,7 +140,10 @@ AS_IF([test "x$ARCHTYPE" = "xx86"],[ > #For now, using lock; addl compatibility mode even for i686, because the > #Pentium III is seen as a i686, but lacks mfence instruction. > #Only using fence for x86_64. > - AS_IF([test "x$host_cpu" != "xi386" -a "x$host_cpu" != "xi486" -a > "x$host_cpu" != "xi586" -a "x$host_cpu" != "xi686"],[ > + # > + #k1om is the name for the Intel MIC family (Xeon Phi). It is an x86_64 > + #variant but lacks fence instructions. > + AS_IF([test "x$host_cpu" != "xi386" -a "x$host_cpu" != "xi486" -a > "x$host_cpu" != "xi586" -a "x$host_cpu" != "xi686" -a "x$host_vendor" != > "xk1om"],[ > AC_MSG_RESULT([yes]) > AC_DEFINE([CONFIG_RCU_HAVE_FENCE], [1]) > ],[ > -- > 1.7.1 > > > _______________________________________________ > lttng-dev mailing list > lttng-dev@lists.lttng.org > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
