* Paul E. McKenney ([email protected]) wrote: > The machine I am using is cortex-a9. It may be necessary to create a > more intelligent mapping to the many variants of ARM. Interestingly > enough, __sync_synchronize() -still- fails, so use an explicit asm > for the dmb instruction. > > Leaving off the '-O' gives freaking slow results. ;-)
Is this -O problem something we should fix at an higher level ? (e.g. for all arch ?) More comments below, > > Signed-off-by: Paul E. McKenney <[email protected]> > --- > > configure.ac | 4 +++ > urcu/arch_armv7l.h | 59 > +++++++++++++++++++++++++++++++++++++++++++++ > urcu/uatomic_arch_armv7l.h | 48 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 111 insertions(+) > > diff --git a/configure.ac b/configure.ac > index 9274337..9e2615f 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -51,6 +51,7 @@ case $host_cpu in > s390x) ARCHTYPE="s390" ;; > sparc64) ARCHTYPE="sparc64" ;; > alpha*) ARCHTYPE="alpha" ;; > + armv7l) ARCHTYPE="armv7l" ;; > *) ARCHTYPE="unknown";; > esac > > @@ -61,6 +62,9 @@ if test "x$ARCHTYPE" != xx86 -a "x$ARCHTYPE" != xppc; then > else > APISRC=tests/api_$ARCHTYPE.h > fi > +if test "x$ARCHTYPE" == xarmv7l; then > + CFLAGS="-mcpu=cortex-a9 -mtune=cortex-a9 -O2" > +fi > > AC_SUBST(ARCHTYPE) > AC_SUBST(SUBARCHTYPE) > diff --git a/urcu/arch_armv7l.h b/urcu/arch_armv7l.h > new file mode 100644 > index 0000000..5920a4d > --- /dev/null > +++ b/urcu/arch_armv7l.h > @@ -0,0 +1,59 @@ > +#ifndef _URCU_ARCH_ARMV7L_H > +#define _URCU_ARCH_ARMV7L_H > + > +/* > + * arch_unknown.h: trivial definitions for the "unknown" architecture. > + * > + * Copyright (c) 2010 Paul E. McKenney, IBM Corporation. > + * Copyright (c) 2009 Mathieu Desnoyers <[email protected]> > + * > + * This library is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * This library is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with this library; if not, write to the Free Software > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 > USA > + */ > + > +#include <urcu/compiler.h> > +#include <urcu/config.h> > + > +#ifdef __cplusplus > +extern "C" { > +#endif > + > +/* We don't know, so guess!!! */ > +#define CACHE_LINE_SIZE 128 > + > +#define mb() asm volatile("dmb":::"memory") > + > +#include <stdlib.h> > +#include <sys/time.h> > + > +typedef unsigned long long cycles_t; > + > +static inline cycles_t get_cycles (void) > +{ > + cycles_t thetime; > + struct timeval tv; > + > + if (gettimeofday(&tv, NULL) != 0) > + return 0; > + thetime = ((cycles_t)tv.tv_sec) * 1000000ULL + ((cycles_t)tv.tv_usec); > + return (cycles_t)thetime; > +} > + > +#ifdef __cplusplus > +} > +#endif > + > +#include <urcu/arch_generic.h> > + > +#endif /* _URCU_ARCH_ARMV7L_H */ > diff --git a/urcu/uatomic_arch_armv7l.h b/urcu/uatomic_arch_armv7l.h > new file mode 100644 > index 0000000..5eece49 > --- /dev/null > +++ b/urcu/uatomic_arch_armv7l.h > @@ -0,0 +1,48 @@ > +#ifndef _URCU_ARCH_UATOMIC_ARMV7L_H > +#define _URCU_ARCH_UATOMIC_ARMV7L_H > + > +/* > + * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved. > + * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved. > + * Copyright (c) 1999-2004 Hewlett-Packard Development Company, L.P. > + * Copyright (c) 2009 Mathieu Desnoyers > + * Copyright (c) 2010 Paul E. McKenney, IBM Corporation > + * (Adapted from uatomic_arch_unknown.h) > + * > + * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED > + * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. > + * > + * Permission is hereby granted to use or copy this program > + * for any purpose, provided the above notices are retained on all copies. > + * Permission to modify the code and to distribute modified code is granted, > + * provided the above notices are retained, and a notice that the code was > + * modified is included with the above copyright notice. > + * > + * Code inspired from libuatomic_ops-1.2, inherited in part from the > + * Boehm-Demers-Weiser conservative garbage collector. > + */ > + > +#include <urcu/compiler.h> > +#include <urcu/system.h> > + > +#ifdef __cplusplus > +extern "C" { > +#endif > + > +/* xchg */ > +#define uatomic_xchg(addr, v) __sync_lock_test_and_set(addr, v); I expect that these __sync_*() operations have missing memory barriers ? It might be safer to do something like: #define uatomic_cmpxchg(addr, old _new) \ {( \ __typeof__(_new) __ret; \ \ smp_mb(); \ __ret = __sync_val_compare_and_swap(addr, old, _new); \ smp_mb(); \ __ret; )} (similar for other primitives) The idea is that I don't trust gcc's __sync_*() implementation if they got the __sync_synchronize() wrong. Thanks, Mathieu > + > +/* cmpxchg */ > +#define uatomic_cmpxchg(addr, old, _new) \ > + __sync_val_compare_and_swap(addr, old, _new) > + > +/* uatomic_add_return */ > +#define uatomic_add_return(addr, v) __sync_add_and_fetch(addr, v) > + > +#ifdef __cplusplus > +} > +#endif > + > +#include <urcu/uatomic_generic.h> > + > +#endif /* _URCU_ARCH_UATOMIC_ARMV7L_H */ -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com _______________________________________________ ltt-dev mailing list [email protected] http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
