I usually force somme access to be uncached. A whole barrier would work, but
the performance cost is way too big.
Just as an example:
static inline void odp_atomic_init_u64(odp_atomic_u64_t *atom, uint64_t val)
{
atom->v = val;
#if __GCC_ATOMIC_LLONG_LOCK_FREE < 2
__atomic_clear(&atom->lock, __ATOMIC_RELAXED);
#endif
}
becomes
static inline void odp_atomic_init_u64(odp_atomic_u64_t *atom, uint64_t val)
{
STORE_U64(atom->v, val);
}
where STORE_U64 forces an uncached write directly to memory.
Nicolas
Le 12/07/2016 à 08:09 AM, Maxim Uvarov a écrit :
> Nicolas, what do you do to solve coherency problem? I think that maybe we are
> missing some api in odp, like read/write barriers.
>
> Maxim.
>
> On 7 December 2016 at 09:54, Nicolas Morey-Chaisemartin <[email protected]
> <mailto:[email protected]>> wrote:
>
>
>
> Le 12/06/2016 à 09:37 PM, Mike Holmes a écrit :
> > On 6 December 2016 at 12:08, Nicolas Morey-Chaisemartin
> > <[email protected] <mailto:[email protected]>> wrote:
> >> Signed-off-by: Nicolas Morey-Chaisemartin <[email protected]
> <mailto:[email protected]>>
> >> ---
> >> helper/Makefile.am | 6 +++---
> >> helper/test/Makefile.am | 6 +++---
> >> 2 files changed, 6 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/helper/Makefile.am b/helper/Makefile.am
> >> index d09d900..c75db00 100644
> >> --- a/helper/Makefile.am
> >> +++ b/helper/Makefile.am
> >> @@ -1,7 +1,7 @@
> >> include $(top_srcdir)/platform/@with_platform@/Makefile.inc
> >>
> >> pkgconfigdir = $(libdir)/pkgconfig
> >> -pkgconfig_DATA = $(top_builddir)/pkgconfig/libodphelper-linux.pc
> >> +pkgconfig_DATA =
> $(top_builddir)/pkgconfig/libodphelper@[email protected]
> > Why would the helpers be tied to the implementation being built ? They
> > should be agnostic and depend on the OS
> I agree that they should not depend on the implementation of ODP. But as
> for libodp, helper might not be ABI compatible.
> The issue is that there's no evident place in the connfigure to select
> which implementation of the helper should be used.
> platform configure.m4 are the easiest place to add this which ties this
> to the platform.
> But I could add an ODPH_LIB_IMPL. So several platforms could use the same
> helper, while keeping the possibility of using non ABI compatible versions in
> other platforms.
>
> > I think the helpers are broken or we need an alternative to linux.c in
> > there, perhaps a odp/helpers/platform/linux/linux.c and
> > odp/helpers/platform/mpaa/linux.c
> I changed it in our git tree. helper/linux.c got moved to
> helper/os/linux/linux.c
> And we added helper/os/nodeos/linux.c and helper/os/mos/linux.c (we have
> 2 OS flavors usable with ODP)
> The platform configure.m4 is in charge of selecting the OS depending on
> flags & compiler selected.
> >
> >> LIB = $(top_builddir)/lib
> >> AM_CFLAGS = -I$(srcdir)/include
> >> @@ -31,7 +31,7 @@ noinst_HEADERS = \
> >> $(srcdir)/odph_lineartable.h \
> >> $(srcdir)/odph_list_internal.h
> >>
> >> -__LIB__libodphelper_linux_la_SOURCES = \
> >> +__LIB__libodphelper@ODP_LIB_FLAVOR@_la_SOURCES = \
> >> eth.c \
> >> ip.c \
> >> chksum.c \
> >> @@ -39,4 +39,4 @@ __LIB__libodphelper_linux_la_SOURCES = \
> >> hashtable.c \
> >> lineartable.c
> >>
> >> -lib_LTLIBRARIES = $(LIB)/libodphelper-linux.la
> <http://libodphelper-linux.la>
> >> +lib_LTLIBRARIES = $(LIB)/libodphelper@[email protected]
> >> diff --git a/helper/test/Makefile.am b/helper/test/Makefile.am
> >> index 545db73..02c260c 100644
> >> --- a/helper/test/Makefile.am
> >> +++ b/helper/test/Makefile.am
> >> @@ -28,10 +28,10 @@ EXTRA_DIST = odpthreads_as_processes
> odpthreads_as_pthreads
> >>
> >> dist_chksum_SOURCES = chksum.c
> >> dist_odpthreads_SOURCES = odpthreads.c
> >> -odpthreads_LDADD = $(LIB)/libodphelper-linux.la
> <http://libodphelper-linux.la> $(LIB)/libodp-linux.la <http://libodp-linux.la>
> >> +odpthreads_LDADD = $(LIB)/libodphelper@[email protected]
> $(LIB)/libodp@[email protected]
> >> dist_thread_SOURCES = thread.c
> >> -thread_LDADD = $(LIB)/libodphelper-linux.la
> <http://libodphelper-linux.la> $(LIB)/libodp-linux.la <http://libodp-linux.la>
> >> +thread_LDADD = $(LIB)/libodphelper@[email protected]
> $(LIB)/libodp@[email protected]
> >> dist_process_SOURCES = process.c
> >> dist_parse_SOURCES = parse.c
> >> -process_LDADD = $(LIB)/libodphelper-linux.la
> <http://libodphelper-linux.la> $(LIB)/libodp-linux.la <http://libodp-linux.la>
> >> +process_LDADD = $(LIB)/libodphelper@[email protected]
> $(LIB)/libodp@[email protected]
> >> dist_table_SOURCES = table.c
> >> --
> >> 2.10.1.4.g0ffc436
> >>
> >>
> >
> >
>
>
