On Tue, May 27, 2014 at 11:29 AM, Sebastian Huber <sebastian.hu...@embedded-brains.de> wrote: > On 2014-05-27 17:21, Gedare Bloom wrote: >> >> On Tue, May 27, 2014 at 10:48 AM, Ralf Kirchner >> <ralf.kirch...@embedded-brains.de> wrote: >>> >>> >Enabling and disabling preemption as done for single core will not work >>> > for SMP. >>> >Thus as a temporary workaround use POSIX mutexes and POSIX condition >>> > variables for SMP instead of the combination of semaphores and preemption >>> > handling used for single core. >>> >--- >>> > cpukit/libblock/src/bdbuf.c | 348 >>> > +++++++++++++++++++++++++++++++++++-------- >>> > 1 Datei geändert, 282 Zeilen hinzugefügt(+), 66 Zeilen entfernt(-) >>> > >>> >diff --git a/cpukit/libblock/src/bdbuf.c b/cpukit/libblock/src/bdbuf.c >>> >index 1e4887c..0caf8f5 100644 >>> >--- a/cpukit/libblock/src/bdbuf.c >>> >+++ b/cpukit/libblock/src/bdbuf.c >>> >@@ -43,6 +43,23 @@ >>> > >>> > #include "rtems/bdbuf.h" >>> > >>> >+#if defined( RTEMS_SMP ) >>> >+ #if defined( RTEMS_POSIX_API ) >>> >+ /* The single core implementation with enabling and disabling >>> > preemption >>> >+ * will not work under SMP. Thus we need to use POSIX mutexes and >>> > POSIX >>> >+ * condition variables as a workaround >>> >+ * Required POSIX mutexes and POSIX condition variables will be >>> > allocated >>> >+ * automatically in confdefs.h if RTEMS_SMP and RTEMS_POSIX_API >>> >+ * are #defined >>> >+ */ >>> >+ #define RTEMS_BDBUF_SMP_WORKAROUND >> >> Workaround implies a temporary solution. Is there a longer-term >> solution in the works? Otherwise, we should just condition this on >> RTEMS_SMP? > > > We need condition variables in the Classic API. > > Is it OK and feasible to require POSIX and use posix condition variables for applications that use the bdbuf? If so, I think this would be better than the workaround that splits the code in these two cases, and probably the SMP and non-SMP can share most code then?
-Gedare >> >> What if RTEMS_SMP is defined, but RTEMS_POSIX_API is not? This would >> be an error here I suppose? Or possibly elsewhere in the bdbuf >> workaround code? Probably it should be accounted in confdefs.h and an >> error emitted? >> > > RTEMS_SMP without RTEMS_POSIX_API falls back to the current situation. You > get a fatal error at run-time. A compile-time error is bad, since this > would break the test suite build. > > -- > Sebastian Huber, embedded brains GmbH > > Address : Dornierstr. 4, D-82178 Puchheim, Germany > Phone : +49 89 189 47 41-16 > Fax : +49 89 189 47 41-09 > E-Mail : sebastian.hu...@embedded-brains.de > PGP : Public key available on request. > > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. > > _______________________________________________ > rtems-devel mailing list > rtems-devel@rtems.org > http://www.rtems.org/mailman/listinfo/rtems-devel _______________________________________________ rtems-devel mailing list rtems-devel@rtems.org http://www.rtems.org/mailman/listinfo/rtems-devel
