From 07ed18d26a342741cb25a4739158c65ed9dd4d09 Mon Sep 17 00:00:00 2001 From: Rogerio Alves Date: Tue, 5 Dec 2017 14:24:14 -0200 Subject: Add elision tunables This patch adds several new tunables to control the behavior of elision on supported platforms[1]. Since elision now depends on tunables, we should always *compile* with elision enabled, and leave the code disabled, but available for runtime selection. This gives us *much* better compile-time testing of the existing code to avoid bit-rot[2]. Tested on ppc, ppc64, ppc64le, s390x and x86_64. [1] This part of the patch was initially proposed by Paul Murphy but was "staled" because the framework have changed since the patch was originally proposed: https://patchwork.sourceware.org/patch/10342/ [2] This part of the patch was inititally proposed as a RFC by Carlos O'Donnell. Make sense to me integrate this on the patch: https://sourceware.org/ml/libc-alpha/2017-05/msg00335.html * elf/dl-tunables.list: Add elision parameters. * manual/tunables.texi: Add entries about elision tunable. * sysdeps/unix/sysv/linux/powerpc/elision-conf.c: Add callback functions to dynamically enable/disable elision. Add multiple callbacks functions to set elision parameters. Deleted __libc_enable_secure check. * sysdeps/unix/sysv/linux/s390/elision-conf.c: Likewise. * sysdeps/unix/sysv/linux/x86/elision-conf.c: Likewise. * configure: Regenerated. * configure.ac: Option enable_lock_elision was deleted. * config.h.in: ENABLE_LOCK_ELISION flag was deleted. * config.make.in: Remove references to enable_lock_elision. * manual/install.texi: Elision configure option was removed. * INSTALL: Regenerated to remove enable_lock_elision. * nptl/Makefile: Disable elision so it can verify error case for destroying a mutex. * sysdeps/powerpc/nptl/elide.h: Cleanup ENABLE_LOCK_ELISION check. Deleted macros for the case when ENABLE_LOCK_ELISION was not defined. * sysdeps/s390/configure: Regenerated. * sysdeps/s390/configure.ac: Remove references to enable_lock_elision.. * nptl/tst-mutex8.c: Deleted all #ifndef ENABLE_LOCK_ELISION from the test. * sysdeps/powerpc/powerpc32/sysdep.h: Deleted all ENABLE_LOCK_ELISION checks. * sysdeps/powerpc/powerpc64/sysdep.h: Likewise. * sysdeps/powerpc/sysdep.h: Likewise. * sysdeps/s390/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/unix/sysv/linux/powerpc/force-elision.h: Likewise. * sysdeps/unix/sysv/linux/s390/elision-conf.h: Likewise. * sysdeps/unix/sysv/linux/s390/force-elision.h: Likewise. * sysdeps/unix/sysv/linux/s390/lowlevellock.h: Likewise. * sysdeps/unix/sysv/linux/s390/Makefile: Remove references to enable-lock-elision. Reviewed-by: Tulio Magno Quites Machado Filho --- nptl/Makefile | 4 ++++ nptl/tst-mutex8.c | 12 ++---------- 2 files changed, 6 insertions(+), 10 deletions(-) (limited to 'nptl') diff --git a/nptl/Makefile b/nptl/Makefile index b0215e12d7..11e6ecd88b 100644 --- a/nptl/Makefile +++ b/nptl/Makefile @@ -714,6 +714,10 @@ endif $(objpfx)tst-compat-forwarder: $(objpfx)tst-compat-forwarder-mod.so +# Disable elision for tst-mutex8 so it can verify error case for +# destroying a mutex. +tst-mutex8-ENV = GLIBC_TUNABLES=glibc.elision.enable=0 + # The tests here better do not run in parallel ifneq ($(filter %tests,$(MAKECMDGOALS)),) .NOTPARALLEL: diff --git a/nptl/tst-mutex8.c b/nptl/tst-mutex8.c index 1d288d243c..ef59db55de 100644 --- a/nptl/tst-mutex8.c +++ b/nptl/tst-mutex8.c @@ -127,9 +127,8 @@ check_type (const char *mas, pthread_mutexattr_t *ma) return 1; } - /* Elided mutexes don't fail destroy. If elision is not explicitly disabled - we don't know, so can also not check this. */ -#ifndef ENABLE_LOCK_ELISION + /* Elided mutexes don't fail destroy, but this test is run with + elision disabled so we can test them. */ e = pthread_mutex_destroy (m); if (e == 0) { @@ -142,7 +141,6 @@ check_type (const char *mas, pthread_mutexattr_t *ma) mas); return 1; } -#endif if (pthread_mutex_unlock (m) != 0) { @@ -157,7 +155,6 @@ check_type (const char *mas, pthread_mutexattr_t *ma) } /* Elided mutexes don't fail destroy. */ -#ifndef ENABLE_LOCK_ELISION e = pthread_mutex_destroy (m); if (e == 0) { @@ -171,7 +168,6 @@ mutex_destroy of self-trylocked mutex did not return EBUSY %s\n", mas); return 1; } -#endif if (pthread_mutex_unlock (m) != 0) { @@ -207,7 +203,6 @@ mutex_destroy of self-trylocked mutex did not return EBUSY %s\n", } /* Elided mutexes don't fail destroy. */ -#ifndef ENABLE_LOCK_ELISION e = pthread_mutex_destroy (m); if (e == 0) { @@ -220,7 +215,6 @@ mutex_destroy of self-trylocked mutex did not return EBUSY %s\n", mutex_destroy of condvar-used mutex did not return EBUSY for %s\n", mas); return 1; } -#endif done = true; if (pthread_cond_signal (&c) != 0) @@ -280,7 +274,6 @@ mutex_destroy of condvar-used mutex did not return EBUSY for %s\n", mas); } /* Elided mutexes don't fail destroy. */ -#ifndef ENABLE_LOCK_ELISION e = pthread_mutex_destroy (m); if (e == 0) { @@ -295,7 +288,6 @@ mutex_destroy of condvar-used mutex did not return EBUSY for %s\n", mas); mas); return 1; } -#endif if (pthread_cancel (th) != 0) { -- cgit 1.4.1