-# smp-support configure option
-AC_ARG_ENABLE([smp-support],
- AS_HELP_STRING([--disable-smp-support], [Disable SMP support. Warning: only use this on uniprocessor systems. [default=enabled]]),
- [def_smp_support=$enableval],
- [def_smp_support="yes"])
-AS_IF([test "x$def_smp_support" = "xyes"], [AC_DEFINE([CONFIG_RCU_SMP], [1])])
-
-
-# From the sched_setaffinity(2)'s man page:
-# ~~~~
-# The CPU affinity system calls were introduced in Linux kernel 2.5.8.
-# The library interfaces were introduced in glibc 2.3. Initially, the
-# glibc interfaces included a cpusetsize argument. In glibc 2.3.3,
-# the cpuset size argument was removed, but this argument was
-# restored in glibc 2.3.4.
-# ~~~~
-
-# In addition to that, some vendors ported the system call to 2.4
-# kernels.
-
-# Furthermore, when the function first appeared, the MASK argument was
-# an unsigned long pointer, while later it was made into a cpu_set_t
-# pointer. Systems that have the cpu_set_t version also should have
-# the CPU_ZERO, CPU_SET, etc. macros.
-
-# All this mess means we have to cater for at least 3 different
-# sched_setaffinity prototypes:
-
-# ~~~~
-# int sched_setaffinity (pid_t pid, unsigned int len, unsigned long *mask);
-# int sched_setaffinity (pid_t __pid, size_t __cpusetsize, const cpu_set_t *__cpuset);
-# int sched_setaffinity (pid_t __pid, const cpu_set_t *__mask);
-# ~~~~
-
-# Since we define _GNU_SOURCE in the sources, must do so too in the
-# autoconf tests, as defining _GNU_SOURCE or not exposes
-# sched_setaffinity bits differently.
-saved_CFLAGS=$CFLAGS
-CFLAGS="$CFLAGS -D_GNU_SOURCE"
-
-# First check if the function is available at all.
-AC_CHECK_FUNCS([sched_setaffinity],[
- # Okay, we have it. Check if also have cpu_set_t. If we don't,
- # then we have the first version using unsigned long, and no
- # CPU_ZERO, etc. macros. If we do have cpu_set_t, we may have the
- # version with 2 or 3 arguments. In that case, CPU_ZERO, etc.,
- # should also be present, but we confirm nonetheless.
-
- AC_CHECK_TYPES([cpu_set_t],[
- # We do have it. Confirm that we have CPU_ZERO, and it actually works.
- AC_MSG_CHECKING([whether CPU_ZERO works])
- AH_TEMPLATE([HAVE_CPU_ZERO], [Defined to 1 if we have CPU_ZERO and it works])
- AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
- #define _GNU_SOURCE
- #include <sched.h>
- int main()
- {
- cpu_set_t foo; CPU_ZERO (&foo);
- return 0;
- }
- ]])
- ],[
- # Works!
- AC_DEFINE(HAVE_CPU_ZERO, 1)
- AC_MSG_RESULT([yes])
- ],[
- AC_MSG_RESULT([no])
- ])
-
- # Check how many arguments does sched_setaffinity take.
- # Should be 3 or 2.
- AC_MSG_CHECKING([how many arguments sched_setaffinity takes])
- AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
- #include <sched.h>
- int main()
- {
- cpu_set_t foo;
- sched_setaffinity (0, sizeof (foo), &foo);
- return 0;
- }
- ]])
- ],
- [sched_set_affinity_args=3],
- [sched_set_affinity_args=2])
- AC_DEFINE_UNQUOTED(SCHED_SETAFFINITY_ARGS, $sched_set_affinity_args,
- [Defined to sched_setaffinity's number of arguments.])
- AC_MSG_RESULT([$sched_set_affinity_args])
- ],[
- # No cpu_set_t, always 3 args.
- AC_DEFINE(SCHED_SETAFFINITY_ARGS, 3)
- ],
- [#include <sched.h>])
-])