Remove --enable-tunables configure option

And make always supported.  The configure option was added on glibc 2.25
and some features require it (such as hwcap mask, huge pages support, and
lock elisition tuning).  It also simplifies the build permutations.

Changes from v1:
 * Remove glibc.rtld.dynamic_sort changes, it is orthogonal and needs
   more discussion.
 * Cleanup more code.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

6 files changed, 4 insertions, 32 deletions

diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index f8bd12d..b4323b2 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -245,11 +245,9 @@ tests-internal += \
   tst-sigcontext-get_pc \
   # tests-internal
 
-ifneq (no,$(have-tunables))
 tests-internal += \
   tst-rseq-disable \
-  # tests-internal $(have-tunables)
-endif
+  # tests-internal
 
 tests-time64 += \
   tst-adjtimex-time64 \
diff --git a/sysdeps/unix/sysv/linux/aarch64/cpu-features.c b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c
index 0380f11..dc09c1c 100644
--- a/sysdeps/unix/sysv/linux/aarch64/cpu-features.c
+++ b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c
@@ -30,7 +30,6 @@
    to see when pointer have been correctly tagged.  */
 #define MTE_ALLOWED_TAGS (0xfffe << PR_MTE_TAG_SHIFT)
 
-#if HAVE_TUNABLES
 struct cpu_list
 {
   const char *name;
@@ -59,19 +58,16 @@ get_midr_from_mcpu (const char *mcpu)
 
   return UINT64_MAX;
 }
-#endif
 
 static inline void
 init_cpu_features (struct cpu_features *cpu_features)
 {
   register uint64_t midr = UINT64_MAX;
 
-#if HAVE_TUNABLES
   /* Get the tunable override.  */
   const char *mcpu = TUNABLE_GET (glibc, cpu, name, const char *, NULL);
   if (mcpu != NULL)
     midr = get_midr_from_mcpu (mcpu);
-#endif
 
   /* If there was no useful tunable override, query the MIDR if the kernel
      allows it.  */
@@ -100,13 +96,11 @@ init_cpu_features (struct cpu_features *cpu_features)
   cpu_features->mte_state = 0;
 
 #ifdef USE_MTAG
-# if HAVE_TUNABLES
   int mte_state = TUNABLE_GET (glibc, mem, tagging, unsigned, 0);
   cpu_features->mte_state = (GLRO (dl_hwcap2) & HWCAP2_MTE) ? mte_state : 0;
   /* If we lack the MTE feature, disable the tunable, since it will
      otherwise cause instructions that won't run on this CPU to be used.  */
   TUNABLE_SET (glibc, mem, tagging, cpu_features->mte_state);
-# endif
 
   if (cpu_features->mte_state & 4)
     /* Enable choosing system-preferred faulting mode.  */
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-conf.c b/sysdeps/unix/sysv/linux/powerpc/elision-conf.c
index 8cd945a..7c98dbd 100644
--- a/sysdeps/unix/sysv/linux/powerpc/elision-conf.c
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-conf.c
@@ -22,9 +22,7 @@
 #include <unistd.h>
 #include <dl-procinfo.h>
 
-#if HAVE_TUNABLES
-# define TUNABLE_NAMESPACE elision
-#endif
+#define TUNABLE_NAMESPACE elision
 #include <elf/dl-tunables.h>
 
 /* Reasonable initial tuning values, may be revised in the future.
@@ -51,7 +49,6 @@ struct elision_config __elision_aconf =
     .skip_trylock_internal_abort = 3,
   };
 
-#if HAVE_TUNABLES
 static inline void
 __always_inline
 do_set_elision_enable (int32_t elision_enable)
@@ -94,14 +91,12 @@ TUNABLE_CALLBACK_FNDECL (skip_lock_internal_abort, int32_t);
 TUNABLE_CALLBACK_FNDECL (skip_lock_out_of_tbegin_retries, int32_t);
 TUNABLE_CALLBACK_FNDECL (try_tbegin, int32_t);
 TUNABLE_CALLBACK_FNDECL (skip_trylock_internal_abort, int32_t);
-#endif
 
 /* Initialize elision.  */
 
 void
 __lll_elision_init (void)
 {
-#if HAVE_TUNABLES
   /* Elision depends on tunables and must be explicitly turned on by setting
      the appropriate tunable on a supported platform.  */
 
@@ -117,7 +112,6 @@ __lll_elision_init (void)
 	       TUNABLE_CALLBACK (set_elision_try_tbegin));
   TUNABLE_GET (skip_trylock_internal_abort, int32_t,
 	       TUNABLE_CALLBACK (set_elision_skip_trylock_internal_abort));
-#endif
 
   /* Linux from 3.9 through 4.2 do not abort HTM transaction on syscalls,
      instead it suspends the transaction and resumes it when returning to
diff --git a/sysdeps/unix/sysv/linux/s390/elision-conf.c b/sysdeps/unix/sysv/linux/s390/elision-conf.c
index 5911e51..6a6d681 100644
--- a/sysdeps/unix/sysv/linux/s390/elision-conf.c
+++ b/sysdeps/unix/sysv/linux/s390/elision-conf.c
@@ -22,9 +22,7 @@
 #include <unistd.h>
 #include <dl-procinfo.h>
 
-#if HAVE_TUNABLES
-# define TUNABLE_NAMESPACE elision
-#endif
+#define TUNABLE_NAMESPACE elision
 #include <elf/dl-tunables.h>
 
 /* Reasonable initial tuning values, may be revised in the future.
@@ -51,7 +49,6 @@ struct elision_config __elision_aconf =
     .skip_trylock_internal_abort = 3,
   };
 
-#if HAVE_TUNABLES
 static inline void
 __always_inline
 do_set_elision_enable (int32_t elision_enable)
@@ -93,14 +90,12 @@ TUNABLE_CALLBACK_FNDECL (skip_lock_internal_abort, int32_t);
 TUNABLE_CALLBACK_FNDECL (skip_lock_out_of_tbegin_retries, int32_t);
 TUNABLE_CALLBACK_FNDECL (try_tbegin, int32_t);
 TUNABLE_CALLBACK_FNDECL (skip_trylock_internal_abort, int32_t);
-#endif
 
 /* Initialize elison.  */
 
 void
 __lll_elision_init (void)
 {
-#if HAVE_TUNABLES
   /* Elision depends on tunables and must be explicitly turned on by setting
      the appropriate tunable on a supported platform.  */
 
@@ -116,7 +111,6 @@ __lll_elision_init (void)
 	       TUNABLE_CALLBACK (set_elision_try_tbegin));
   TUNABLE_GET (skip_trylock_internal_abort, int32_t,
 	       TUNABLE_CALLBACK (set_elision_skip_trylock_internal_abort));
-#endif
 
   if (!__pthread_force_elision)
     __elision_aconf.try_tbegin = 0; /* Disable elision on rwlocks.  */
diff --git a/sysdeps/unix/sysv/linux/x86/elision-conf.c b/sysdeps/unix/sysv/linux/x86/elision-conf.c
index 6447bda..cfd9a71 100644
--- a/sysdeps/unix/sysv/linux/x86/elision-conf.c
+++ b/sysdeps/unix/sysv/linux/x86/elision-conf.c
@@ -22,9 +22,7 @@
 #include <elision-conf.h>
 #include <unistd.h>
 
-#if HAVE_TUNABLES
-# define TUNABLE_NAMESPACE elision
-#endif
+#define TUNABLE_NAMESPACE elision
 #include <elf/dl-tunables.h>
 
 /* Reasonable initial tuning values, may be revised in the future.
@@ -48,7 +46,6 @@ struct elision_config __elision_aconf =
     .skip_trylock_internal_abort = 3,
   };
 
-#if HAVE_TUNABLES
 static __always_inline void
 do_set_elision_enable (int32_t elision_enable)
 {
@@ -87,14 +84,12 @@ TUNABLE_CALLBACK_FNDECL (skip_lock_busy, int32_t);
 TUNABLE_CALLBACK_FNDECL (skip_lock_internal_abort, int32_t);
 TUNABLE_CALLBACK_FNDECL (retry_try_xbegin, int32_t);
 TUNABLE_CALLBACK_FNDECL (skip_trylock_internal_abort, int32_t);
-#endif
 
 /* Initialize elision.  */
 
 void
 __lll_elision_init (void)
 {
-#if HAVE_TUNABLES
   /* Elision depends on tunables and must be explicitly turned on by setting
      the appropriate tunable on a supported platform.  */
 
@@ -108,7 +103,6 @@ __lll_elision_init (void)
 	       TUNABLE_CALLBACK (set_elision_retry_try_xbegin));
   TUNABLE_GET (skip_trylock_internal_abort, int32_t,
 	       TUNABLE_CALLBACK (set_elision_skip_trylock_internal_abort));
-#endif
 
   if (!__pthread_force_elision)
     __elision_aconf.retry_try_xbegin = 0; /* Disable elision on rwlocks.  */
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/Makefile b/sysdeps/unix/sysv/linux/x86_64/64/Makefile
index 8ff4f27..1bf7d52 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/Makefile
+++ b/sysdeps/unix/sysv/linux/x86_64/64/Makefile
@@ -2,7 +2,6 @@
 default-abi := 64
 
 ifeq ($(subdir),elf)
-ifneq ($(have-tunables),no)
 
 tests-map-32bit = \
   tst-map-32bit-1a \
@@ -24,4 +23,3 @@ tst-map-32bit-1b-ENV = GLIBC_TUNABLES=glibc.cpu.prefer_map_32bit_exec=1
 $(objpfx)tst-map-32bit-1b: $(objpfx)tst-map-32bit-mod.so
 
 endif
-endif