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23 Commits
Author | SHA1 | Message | Date | |
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Samuel Thibault
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a5df0318ef |
hurd: add gscope support
* elf/dl-support.c [!THREAD_GSCOPE_IN_TCB] (_dl_thread_gscope_count): Define variable. * sysdeps/generic/ldsodefs.h [!THREAD_GSCOPE_IN_TCB] (struct rtld_global): Add _dl_thread_gscope_count member. * sysdeps/mach/hurd/tls.h: Include <atomic.h>. [!defined __ASSEMBLER__] (THREAD_GSCOPE_GLOBAL, THREAD_GSCOPE_SET_FLAG, THREAD_GSCOPE_RESET_FLAG, THREAD_GSCOPE_WAIT): Define macros. * sysdeps/generic/tls.h: Document THREAD_GSCOPE_IN_TCB. * sysdeps/aarch64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/alpha/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/arm/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/hppa/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/i386/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/ia64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/m68k/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/microblaze/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/mips/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/nios2/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/powerpc/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/riscv/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/s390/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/sh/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/sparc/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/tile/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/x86_64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. |
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Joseph Myers
|
688903eb3e |
Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise. |
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Adhemerval Zanella
|
06be6368da |
nptl: Define __PTHREAD_MUTEX_{NUSERS_AFTER_KIND,USE_UNION}
This patch adds two new internal defines to set the internal pthread_mutex_t layout required by the supported ABIS: 1. __PTHREAD_MUTEX_NUSERS_AFTER_KIND which control whether to define __nusers fields before or after __kind. The preferred value for is 0 for new ports and it sets __nusers before __kind. 2. __PTHREAD_MUTEX_USE_UNION which control whether internal __spins and __list members will be place inside an union for linuxthreads compatibility. The preferred value is 0 for ports and it sets to not use an union to define both fields. It fixes the wrong offsets value for __kind value on x86_64-linux-gnu-x32. Checked with a make check run-built-tests=no on all afected ABIs. [BZ #22298] * nptl/allocatestack.c (allocate_stack): Check if __PTHREAD_MUTEX_HAVE_PREV is non-zero, instead if __PTHREAD_MUTEX_HAVE_PREV is defined. * nptl/descr.h (pthread): Likewise. * nptl/nptl-init.c (__pthread_initialize_minimal_internal): Likewise. * nptl/pthread_create.c (START_THREAD_DEFN): Likewise. * sysdeps/nptl/fork.c (__libc_fork): Likewise. * sysdeps/nptl/pthread.h (PTHREAD_MUTEX_INITIALIZER): Likewise. * sysdeps/nptl/bits/thread-shared-types.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): New defines. (__pthread_internal_list): Check __PTHREAD_MUTEX_USE_UNION instead of __WORDSIZE for internal layout. (__pthread_mutex_s): Check __PTHREAD_MUTEX_NUSERS_AFTER_KIND instead of __WORDSIZE for internal __nusers layout and __PTHREAD_MUTEX_USE_UNION instead of __WORDSIZE whether to use an union for __spins and __list fields. (__PTHREAD_MUTEX_HAVE_PREV): Define also for __PTHREAD_MUTEX_USE_UNION case. * sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): New defines. * sysdeps/alpha/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/arm/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/hppa/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/ia64/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/m68k/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/mips/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/nios2/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/powerpc/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/s390/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/sh/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/sparc/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/tile/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/x86/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> |
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Adhemerval Zanella
|
dff91cd45e |
nptl: Add tests for internal pthread_mutex_t offsets
This patch adds a new build test to check for internal fields offsets for user visible internal field. Although currently the only field which is statically initialized to a non zero value is pthread_mutex_t.__data.__kind value, the tests also check the offset of __kind, __spins, __elision (if supported), and __list internal member. A internal header (pthread-offset.h) is added to each major ABI with the reference value. Checked on x86_64-linux-gnu and with a build check for all affected ABIs (aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf, hppa-linux-gnu, i686-linux-gnu, ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips64-linux-gnu, mips64-n32-linux-gnu, mips-linux-gnu, powerpc64le-linux-gnu, powerpc-linux-gnu, s390-linux-gnu, s390x-linux-gnu, sh4-linux-gnu, sparc64-linux-gnu, sparcv9-linux-gnu, tilegx-linux-gnu, tilegx-linux-gnu-x32, tilepro-linux-gnu, x86_64-linux-gnu, and x86_64-linux-x32). * nptl/pthreadP.h (ASSERT_PTHREAD_STRING, ASSERT_PTHREAD_INTERNAL_OFFSET): New macro. * nptl/pthread_mutex_init.c (__pthread_mutex_init): Add build time checks for internal pthread_mutex_t offsets. * sysdeps/aarch64/nptl/pthread-offsets.h (__PTHREAD_MUTEX_NUSERS_OFFSET, __PTHREAD_MUTEX_KIND_OFFSET, __PTHREAD_MUTEX_SPINS_OFFSET, __PTHREAD_MUTEX_ELISION_OFFSET, __PTHREAD_MUTEX_LIST_OFFSET): New macro. * sysdeps/alpha/nptl/pthread-offsets.h: Likewise. * sysdeps/arm/nptl/pthread-offsets.h: Likewise. * sysdeps/hppa/nptl/pthread-offsets.h: Likewise. * sysdeps/i386/nptl/pthread-offsets.h: Likewise. * sysdeps/ia64/nptl/pthread-offsets.h: Likewise. * sysdeps/m68k/nptl/pthread-offsets.h: Likewise. * sysdeps/microblaze/nptl/pthread-offsets.h: Likewise. * sysdeps/mips/nptl/pthread-offsets.h: Likewise. * sysdeps/nios2/nptl/pthread-offsets.h: Likewise. * sysdeps/powerpc/nptl/pthread-offsets.h: Likewise. * sysdeps/s390/nptl/pthread-offsets.h: Likewise. * sysdeps/sh/nptl/pthread-offsets.h: Likewise. * sysdeps/sparc/nptl/pthread-offsets.h: Likewise. * sysdeps/tile/nptl/pthread-offsets.h: Likewise. * sysdeps/x86_64/nptl/pthread-offsets.h: Likewise. Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> |
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Stefan Liebler
|
12d2dd7060 |
Optimize generic spinlock code and use C11 like atomic macros.
This patch optimizes the generic spinlock code. The type pthread_spinlock_t is a typedef to volatile int on all archs. Passing a volatile pointer to the atomic macros which are not mapped to the C11 atomic builtins can lead to extra stores and loads to stack if such a macro creates a temporary variable by using "__typeof (*(mem)) tmp;". Thus, those macros which are used by spinlock code - atomic_exchange_acquire, atomic_load_relaxed, atomic_compare_exchange_weak - have to be adjusted. According to the comment from Szabolcs Nagy, the type of a cast expression is unqualified (see http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_423.htm): __typeof ((__typeof (*(mem)) *(mem)) tmp; Thus from spinlock perspective the variable tmp is of type int instead of type volatile int. This patch adjusts those macros in include/atomic.h. With this construct GCC >= 5 omits the extra stores and loads. The atomic macros are replaced by the C11 like atomic macros and thus the code is aligned to it. The pthread_spin_unlock implementation is now using release memory order instead of sequentially consistent memory order. The issue with passed volatile int pointers applies to the C11 like atomic macros as well as the ones used before. I've added a glibc_likely hint to the first atomic exchange in pthread_spin_lock in order to return immediately to the caller if the lock is free. Without the hint, there is an additional jump if the lock is free. I've added the atomic_spin_nop macro within the loop of plain reads. The plain reads are also realized by C11 like atomic_load_relaxed macro. The new define ATOMIC_EXCHANGE_USES_CAS determines if the first try to acquire the spinlock in pthread_spin_lock or pthread_spin_trylock is an exchange or a CAS. This is defined in atomic-machine.h for all architectures. The define SPIN_LOCK_READS_BETWEEN_CMPXCHG is now removed. There is no technical reason for throwing in a CAS every now and then, and so far we have no evidence that it can improve performance. If that would be the case, we have to adjust other spin-waiting loops elsewhere, too! Using a CAS loop without plain reads is not a good idea on many targets and wasn't used by one. Thus there is now no option to do so. Architectures are now using the generic spinlock automatically if they do not provide an own implementation. Thus the pthread_spin_lock.c files in sysdeps folder are deleted. ChangeLog: * NEWS: Mention new spinlock implementation. * include/atomic.h: (__atomic_val_bysize): Cast type to omit volatile qualifier. (atomic_exchange_acq): Likewise. (atomic_load_relaxed): Likewise. (ATOMIC_EXCHANGE_USES_CAS): Check definition. * nptl/pthread_spin_init.c (pthread_spin_init): Use atomic_store_relaxed. * nptl/pthread_spin_lock.c (pthread_spin_lock): Use C11-like atomic macros. * nptl/pthread_spin_trylock.c (pthread_spin_trylock): Likewise. * nptl/pthread_spin_unlock.c (pthread_spin_unlock): Use atomic_store_release. * sysdeps/aarch64/nptl/pthread_spin_lock.c: Delete File. * sysdeps/arm/nptl/pthread_spin_lock.c: Likewise. * sysdeps/hppa/nptl/pthread_spin_lock.c: Likewise. * sysdeps/m68k/nptl/pthread_spin_lock.c: Likewise. * sysdeps/microblaze/nptl/pthread_spin_lock.c: Likewise. * sysdeps/mips/nptl/pthread_spin_lock.c: Likewise. * sysdeps/nios2/nptl/pthread_spin_lock.c: Likewise. * sysdeps/aarch64/atomic-machine.h (ATOMIC_EXCHANGE_USES_CAS): Define. * sysdeps/alpha/atomic-machine.h: Likewise. * sysdeps/arm/atomic-machine.h: Likewise. * sysdeps/i386/atomic-machine.h: Likewise. * sysdeps/ia64/atomic-machine.h: Likewise. * sysdeps/m68k/coldfire/atomic-machine.h: Likewise. * sysdeps/m68k/m680x0/m68020/atomic-machine.h: Likewise. * sysdeps/microblaze/atomic-machine.h: Likewise. * sysdeps/mips/atomic-machine.h: Likewise. * sysdeps/powerpc/powerpc32/atomic-machine.h: Likewise. * sysdeps/powerpc/powerpc64/atomic-machine.h: Likewise. * sysdeps/s390/atomic-machine.h: Likewise. * sysdeps/sparc/sparc32/atomic-machine.h: Likewise. * sysdeps/sparc/sparc32/sparcv9/atomic-machine.h: Likewise. * sysdeps/sparc/sparc64/atomic-machine.h: Likewise. * sysdeps/tile/tilegx/atomic-machine.h: Likewise. * sysdeps/tile/tilepro/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/hppa/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/nios2/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/sh/atomic-machine.h: Likewise. * sysdeps/x86_64/atomic-machine.h: Likewise. |
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Adhemerval Zanella
|
eab380d8ec |
Move shared pthread definitions to common headers
This patch removes all the replicated pthread definition accross the architectures and consolidates it on shared headers. The new organization is as follow: * Architecture specific definition (such as pthread types sizes) are place in the new pthreadtypes-arch.h header in arch specific path. * All shared structure definition are moved to a common NPTL header at sysdeps/nptl/bits/pthreadtypes.h (with now includes the arch specific one for internal definitions). * Also, for C11 future thread support, both mutex and condition definition are placed in a common header at sysdeps/nptl/bits/thread-shared-types.h. It is also a refactor patch without expected functional changes. Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips{64}-linux-gnu, nios2-linux-gnu, powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu, tile{pro,gx}-linux-gnu, and x86_64-linux-gnu). * posix/Makefile (headers): Add pthreadtypes-arch.h and thread-shared-types.h. * sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h: New file: arch specific thread definition. * sysdeps/alpha/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/arm/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/hppa/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/ia64/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/m68k/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/mips/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/nios2/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/powerpc/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/s390/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/sh/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/sparc/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/tile/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/x86/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/nptl/bits/thread-shared-types.h: New file: shared thread definition between POSIX and C11. * sysdeps/aarch64/nptl/bits/pthreadtypes.h.: Remove file. * sysdeps/alpha/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/arm/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/hppa/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/m68k/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/microblaze/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/mips/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/nios2/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/ia64/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/powerpc/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/s390/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/sh/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/sparc/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/tile/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/x86/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/nptl/bits/pthreadtypes.h: New file: common thread definitions shared across all architectures. |
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Torvald Riegel
|
cc25c8b4c1 |
New pthread rwlock that is more scalable.
This replaces the pthread rwlock with a new implementation that uses a more scalable algorithm (primarily through not using a critical section anymore to make state changes). The fast path for rdlock acquisition and release is now basically a single atomic read-modify write or CAS and a few branches. See nptl/pthread_rwlock_common.c for details. * nptl/DESIGN-rwlock.txt: Remove. * nptl/lowlevelrwlock.sym: Remove. * nptl/Makefile: Add new tests. * nptl/pthread_rwlock_common.c: New file. Contains the new rwlock. * nptl/pthreadP.h (PTHREAD_RWLOCK_PREFER_READER_P): Remove. (PTHREAD_RWLOCK_WRPHASE, PTHREAD_RWLOCK_WRLOCKED, PTHREAD_RWLOCK_RWAITING, PTHREAD_RWLOCK_READER_SHIFT, PTHREAD_RWLOCK_READER_OVERFLOW, PTHREAD_RWLOCK_WRHANDOVER, PTHREAD_RWLOCK_FUTEX_USED): New. * nptl/pthread_rwlock_init.c (__pthread_rwlock_init): Adapt to new implementation. * nptl/pthread_rwlock_rdlock.c (__pthread_rwlock_rdlock_slow): Remove. (__pthread_rwlock_rdlock): Adapt. * nptl/pthread_rwlock_timedrdlock.c (pthread_rwlock_timedrdlock): Adapt. * nptl/pthread_rwlock_timedwrlock.c (pthread_rwlock_timedwrlock): Adapt. * nptl/pthread_rwlock_trywrlock.c (pthread_rwlock_trywrlock): Adapt. * nptl/pthread_rwlock_tryrdlock.c (pthread_rwlock_tryrdlock): Adapt. * nptl/pthread_rwlock_unlock.c (pthread_rwlock_unlock): Adapt. * nptl/pthread_rwlock_wrlock.c (__pthread_rwlock_wrlock_slow): Remove. (__pthread_rwlock_wrlock): Adapt. * nptl/tst-rwlock10.c: Adapt. * nptl/tst-rwlock11.c: Adapt. * nptl/tst-rwlock17.c: New file. * nptl/tst-rwlock18.c: New file. * nptl/tst-rwlock19.c: New file. * nptl/tst-rwlock2b.c: New file. * nptl/tst-rwlock8.c: Adapt. * nptl/tst-rwlock9.c: Adapt. * sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/hppa/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/sparc/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/x86/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * nptl/nptl-printers.py (): Adapt. * nptl/nptl_lock_constants.pysym: Adapt. * nptl/test-rwlock-printers.py: Adapt. * nptl/test-rwlockattr-printers.c: Adapt. * nptl/test-rwlockattr-printers.py: Adapt. |
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Joseph Myers
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bfff8b1bec | Update copyright dates with scripts/update-copyrights. | ||
Torvald Riegel
|
ed19993b5b |
New condvar implementation that provides stronger ordering guarantees.
This is a new implementation for condition variables, required after http://austingroupbugs.net/view.php?id=609 to fix bug 13165. In essence, we need to be stricter in which waiters a signal or broadcast is required to wake up; this couldn't be solved using the old algorithm. ISO C++ made a similar clarification, so this also fixes a bug in current libstdc++, for example. We can't use the old algorithm anymore because futexes do not guarantee to wake in FIFO order. Thus, when we wake, we can't simply let any waiter grab a signal, but we need to ensure that one of the waiters happening before the signal is woken up. This is something the previous algorithm violated (see bug 13165). There's another issue specific to condvars: ABA issues on the underlying futexes. Unlike mutexes that have just three states, or semaphores that have no tokens or a limited number of them, the state of a condvar is the *order* of the waiters. A waiter on a semaphore can grab a token whenever one is available; a condvar waiter must only consume a signal if it is eligible to do so as determined by the relative order of the waiter and the signal. Therefore, this new algorithm maintains two groups of waiters: Those eligible to consume signals (G1), and those that have to wait until previous waiters have consumed signals (G2). Once G1 is empty, G2 becomes the new G1. 64b counters are used to avoid ABA issues. This condvar doesn't yet use a requeue optimization (ie, on a broadcast, waking just one thread and requeueing all others on the futex of the mutex supplied by the program). I don't think doing the requeue is necessarily the right approach (but I haven't done real measurements yet): * If a program expects to wake many threads at the same time and make that scalable, a condvar isn't great anyway because of how it requires waiters to operate mutually exclusive (due to the mutex usage). Thus, a thundering herd problem is a scalability problem with or without the optimization. Using something like a semaphore might be more appropriate in such a case. * The scalability problem is actually at the mutex side; the condvar could help (and it tries to with the requeue optimization), but it should be the mutex who decides how that is done, and whether it is done at all. * Forcing all but one waiter into the kernel-side wait queue of the mutex prevents/avoids the use of lock elision on the mutex. Thus, it prevents the only cure against the underlying scalability problem inherent to condvars. * If condvars use short critical sections (ie, hold the mutex just to check a binary flag or such), which they should do ideally, then forcing all those waiter to proceed serially with kernel-based hand-off (ie, futex ops in the mutex' contended state, via the futex wait queues) will be less efficient than just letting a scalable mutex implementation take care of it. Our current mutex impl doesn't employ spinning at all, but if critical sections are short, spinning can be much better. * Doing the requeue stuff requires all waiters to always drive the mutex into the contended state. This leads to each waiter having to call futex_wake after lock release, even if this wouldn't be necessary. [BZ #13165] * nptl/pthread_cond_broadcast.c (__pthread_cond_broadcast): Rewrite to use new algorithm. * nptl/pthread_cond_destroy.c (__pthread_cond_destroy): Likewise. * nptl/pthread_cond_init.c (__pthread_cond_init): Likewise. * nptl/pthread_cond_signal.c (__pthread_cond_signal): Likewise. * nptl/pthread_cond_wait.c (__pthread_cond_wait): Likewise. (__pthread_cond_timedwait): Move here from pthread_cond_timedwait.c. (__condvar_confirm_wakeup, __condvar_cancel_waiting, __condvar_cleanup_waiting, __condvar_dec_grefs, __pthread_cond_wait_common): New. (__condvar_cleanup): Remove. * npt/pthread_condattr_getclock.c (pthread_condattr_getclock): Adapt. * npt/pthread_condattr_setclock.c (pthread_condattr_setclock): Likewise. * npt/pthread_condattr_getpshared.c (pthread_condattr_getpshared): Likewise. * npt/pthread_condattr_init.c (pthread_condattr_init): Likewise. * nptl/tst-cond1.c: Add comment. * nptl/tst-cond20.c (do_test): Adapt. * nptl/tst-cond22.c (do_test): Likewise. * sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_cond_t): Adapt structure. * sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/x86/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/nptl/internaltypes.h (COND_NWAITERS_SHIFT): Remove. (COND_CLOCK_BITS): Adapt. * sysdeps/nptl/pthread.h (PTHREAD_COND_INITIALIZER): Adapt. * nptl/pthreadP.h (__PTHREAD_COND_CLOCK_MONOTONIC_MASK, __PTHREAD_COND_SHARED_MASK): New. * nptl/nptl-printers.py (CLOCK_IDS): Remove. (ConditionVariablePrinter, ConditionVariableAttributesPrinter): Adapt. * nptl/nptl_lock_constants.pysym: Adapt. * nptl/test-cond-printers.py: Adapt. * sysdeps/unix/sysv/linux/hppa/internaltypes.h (cond_compat_clear, cond_compat_check_and_clear): Adapt. * sysdeps/unix/sysv/linux/hppa/pthread_cond_timedwait.c: Remove file ... * sysdeps/unix/sysv/linux/hppa/pthread_cond_wait.c (__pthread_cond_timedwait): ... and move here. * nptl/DESIGN-condvar.txt: Remove file. * nptl/lowlevelcond.sym: Likewise. * nptl/pthread_cond_timedwait.c: Likewise. * sysdeps/unix/sysv/linux/i386/i486/pthread_cond_broadcast.S: Likewise. * sysdeps/unix/sysv/linux/i386/i486/pthread_cond_signal.S: Likewise. * sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i486/pthread_cond_wait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i586/pthread_cond_broadcast.S: Likewise. * sysdeps/unix/sysv/linux/i386/i586/pthread_cond_signal.S: Likewise. * sysdeps/unix/sysv/linux/i386/i586/pthread_cond_timedwait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i586/pthread_cond_wait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i686/pthread_cond_broadcast.S: Likewise. * sysdeps/unix/sysv/linux/i386/i686/pthread_cond_signal.S: Likewise. * sysdeps/unix/sysv/linux/i386/i686/pthread_cond_timedwait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i686/pthread_cond_wait.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_cond_broadcast.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S: Likewise. |
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Adhemerval Zanella
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c579f48edb |
Remove cached PID/TID in clone
This patch remove the PID cache and usage in current GLIBC code. Current usage is mainly used a performance optimization to avoid the syscall, however it adds some issues: - The exposed clone syscall will try to set pid/tid to make the new thread somewhat compatible with current GLIBC assumptions. This cause a set of issue with new workloads and usecases (such as BZ#17214 and [1]) as well for new internal usage of clone to optimize other algorithms (such as clone plus CLONE_VM for posix_spawn, BZ#19957). - The caching complexity also added some bugs in the past [2] [3] and requires more effort of each port to handle such requirements (for both clone and vfork implementation). - Caching performance gain in mainly on getpid and some specific code paths. The getpid performance leverage is questionable [4], either by the idea of getpid being a hotspot as for the getpid implementation itself (if it is indeed a justifiable hotspot a vDSO symbol could let to a much more simpler solution). Other usage is mainly for non usual code paths, such as pthread cancellation signal and handling. For thread creation (on stack allocation) the code simplification in fact adds some performance gain due the no need of transverse the stack cache and invalidate each element pid. Other thread usages will require a direct getpid syscall, such as cancellation/setxid signal, thread cancellation, thread fail path (at create_thread), and thread signal (pthread_kill and pthread_sigqueue). However these are hardly usual hotspots and I think adding a syscall is justifiable. It also simplifies both the clone and vfork arch-specific implementation. And by review each fork implementation there are some discrepancies that this patch also solves: - microblaze clone/vfork does not set/reset the pid/tid field - hppa uses the default vfork implementation that fallback to fork. Since vfork is deprecated I do not think we should bother with it. The patch also removes the TID caching in clone. My understanding for such semantic is try provide some pthread usage after a user program issue clone directly (as done by thread creation with CLONE_PARENT_SETTID and pthread tid member). However, as stated before in multiple discussions threads, GLIBC provides clone syscalls without further supporting all this semantics. I ran a full make check on x86_64, x32, i686, armhf, aarch64, and powerpc64le. For sparc32, sparc64, and mips I ran the basic fork and vfork tests from posix/ folder (on a qemu system). So it would require further testing on alpha, hppa, ia64, m68k, nios2, s390, sh, and tile (I excluded microblaze because it is already implementing the patch semantic regarding clone/vfork). [1] https://codereview.chromium.org/800183004/ [2] https://sourceware.org/ml/libc-alpha/2006-07/msg00123.html [3] https://sourceware.org/bugzilla/show_bug.cgi?id=15368 [4] http://yarchive.net/comp/linux/getpid_caching.html * sysdeps/nptl/fork.c (__libc_fork): Remove pid cache setting. * nptl/allocatestack.c (allocate_stack): Likewise. (__reclaim_stacks): Likewise. (setxid_signal_thread): Obtain pid through syscall. * nptl/nptl-init.c (sigcancel_handler): Likewise. (sighandle_setxid): Likewise. * nptl/pthread_cancel.c (pthread_cancel): Likewise. * sysdeps/unix/sysv/linux/pthread_kill.c (__pthread_kill): Likewise. * sysdeps/unix/sysv/linux/pthread_sigqueue.c (pthread_sigqueue): Likewise. * sysdeps/unix/sysv/linux/createthread.c (create_thread): Likewise. * sysdeps/unix/sysv/linux/getpid.c: Remove file. * nptl/descr.h (struct pthread): Change comment about pid value. * nptl/pthread_getattr_np.c (pthread_getattr_np): Remove thread pid assert. * sysdeps/unix/sysv/linux/pthread-pids.h (__pthread_initialize_pids): Do not set pid value. * nptl_db/td_ta_thr_iter.c (iterate_thread_list): Remove thread pid cache check. * nptl_db/td_thr_validate.c (td_thr_validate): Likewise. * sysdeps/aarch64/nptl/tcb-offsets.sym: Remove pid offset. * sysdeps/alpha/nptl/tcb-offsets.sym: Likewise. * sysdeps/arm/nptl/tcb-offsets.sym: Likewise. * sysdeps/hppa/nptl/tcb-offsets.sym: Likewise. * sysdeps/i386/nptl/tcb-offsets.sym: Likewise. * sysdeps/ia64/nptl/tcb-offsets.sym: Likewise. * sysdeps/m68k/nptl/tcb-offsets.sym: Likewise. * sysdeps/microblaze/nptl/tcb-offsets.sym: Likewise. * sysdeps/mips/nptl/tcb-offsets.sym: Likewise. * sysdeps/nios2/nptl/tcb-offsets.sym: Likewise. * sysdeps/powerpc/nptl/tcb-offsets.sym: Likewise. * sysdeps/s390/nptl/tcb-offsets.sym: Likewise. * sysdeps/sh/nptl/tcb-offsets.sym: Likewise. * sysdeps/sparc/nptl/tcb-offsets.sym: Likewise. * sysdeps/tile/nptl/tcb-offsets.sym: Likewise. * sysdeps/x86_64/nptl/tcb-offsets.sym: Likewise. * sysdeps/unix/sysv/linux/aarch64/clone.S: Remove pid and tid caching. * sysdeps/unix/sysv/linux/alpha/clone.S: Likewise. * sysdeps/unix/sysv/linux/arm/clone.S: Likewise. * sysdeps/unix/sysv/linux/hppa/clone.S: Likewise. * sysdeps/unix/sysv/linux/i386/clone.S: Likewise. * sysdeps/unix/sysv/linux/ia64/clone2.S: Likewise. * sysdeps/unix/sysv/linux/mips/clone.S: Likewise. * sysdeps/unix/sysv/linux/nios2/clone.S: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/clone.S: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/clone.S: Likewise. * sysdeps/unix/sysv/linux/sh/clone.S: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/clone.S: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/clone.S: Likewise. * sysdeps/unix/sysv/linux/tile/clone.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/clone.S: Likewise. * sysdeps/unix/sysv/linux/aarch64/vfork.S: Remove pid set and reset. * sysdeps/unix/sysv/linux/alpha/vfork.S: Likewise. * sysdeps/unix/sysv/linux/arm/vfork.S: Likewise. * sysdeps/unix/sysv/linux/i386/vfork.S: Likewise. * sysdeps/unix/sysv/linux/ia64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/m68k/clone.S: Likewise. * sysdeps/unix/sysv/linux/m68k/vfork.S: Likewise. * sysdeps/unix/sysv/linux/mips/vfork.S: Likewise. * sysdeps/unix/sysv/linux/nios2/vfork.S: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/vfork.S: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/vfork.S: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/sh/vfork.S: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/vfork.S: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/tile/vfork.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/tst-clone2.c (f): Remove direct pthread struct access. (clone_test): Remove function. (do_test): Rewrite to take in consideration pid is not cached anymore. |
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Florian Weimer
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c74940f2a7 | nptl: Document the reason why __kind in pthread_mutex_t is part of the ABI | ||
Florian Weimer
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d9067fca40 |
Do not override objects in libc.a in other static libraries [BZ #20452]
With this change, we no longer add sysdep.o and similar objects which are present in libc.a to other static libraries. |
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Florian Weimer
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aca1daef29 |
elf: Consolidate machine-agnostic DTV definitions in <dl-dtv.h>
Identical definitions of dtv_t and TLS_DTV_UNALLOCATED were repeated for all architectures using DTVs. |
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Joseph Myers
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f7a9f785e5 | Update copyright dates with scripts/update-copyrights. | ||
Andrew Bennett
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7498d7676d |
MIPS: Only use .set mips* assembler directives when necessary
There are a few .set mips* assembler directives used in the MIPS specific sysdep code that force an instruction to be assembled for a specific ISA. The reason for these is to allow an instruction to be encoded when it might not be supported in the current ISA (when the code is run the Linux kernel will trap and emulate any unsupported instructions). Unfortunately forcing a specific ISA means that when assembling for a newer ISA, where the instruction has a different encoding, the wrong encoding will be used. * sysdeps/mips/bits/atomic.h [_MIPS_SIM == _ABIO32] (MIPS_PUSH_MIPS2): Only use .set mips2 if the current ISA is below mips2. * sysdeps/mips/sys/tas.h [_MIPS_SIM == _ABIO32] (_test_and_set): Likewise. * sysdeps/mips/nptl/tls.h (READ_THREAD_POINTER): Only use .set mips32r2 if the current ISA is below mips32r2. * sysdeps/mips/tls-macros.h (TLS_RDHWR): New define. (TLS_IE): Updated to use the TLD_RDHWR macro. (TLS_LE): Likewise. * sysdeps/unix/mips/sysdep.h (__mips_isa_rev): Moved out of #ifdef __ASSEMBLER__ condition. |
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Joseph Myers
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b168057aaa | Update copyright dates with scripts/update-copyrights. | ||
Joseph Myers
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29c4f53e2a |
Move architecture shlib-versions files to Linux-specific directories.
Various architectures have files such as sysdeps/<arch>/shlib-versions whose contents are in fact entirely Linux-specific, relating only to the symbol / shared library versions for the port to Linux on that architecture, when any future port to a different OS on that architecture would use the symbol version of the glibc release it goes in, as standard for new ports. This patch moves such files under sysdeps/unix/sysv/linux/, merging in the contents of sysdeps/<arch>/nptl/shlib-versions in the process. The only bits not moved are those relating to libgcc_s versions, which don't appear OS-specific in the same way that glibc's symbol versions so. It deliberately does not change the regular expressions given for matching configurations in each file; some match only Linux although not Linux-specific, or match other OSes although Linux-specific. It is with a view to at least the following further cleanups: * Move architecture-specific content from the toplevel shlib-versions and nptl/shlib-versions into sysdeps shlib-versions files, so eliminating another difference between ex-ports and non-ex-ports architectures. * Likewise, for OS-specific content in shlib-versions files. * At that point, the first field in shlib-versions files (the regular expression matching a configuration triplet) should be redundant, so eliminate that field and leave shlib-versions selection working purely on a sysdeps basis (with limited use of %ifdef in shlib-versions files when needed) rather than having its own separate mechanism to select what configuration information is relevant. * Move the build of gnu/lib-names.h to a similar mechanism to that used for gnu/stubs.h (each library build installing a version of the header specifically for that build), so we can eliminate the duplication of soname information in the makefiles and get it purely from shlib-versions files again. There may be other cleanups possible as well (in particular, I'm not sure that all cases where the same "Earliest symbol set" information is repeated for many different libraries actually should need to repeat it rather than specifying it just once for DEFAULT for the given configuration, and separately specifying any non-default choices of soname). Tested x86_64 that the installed shared libraries are unchanged by this patch. * sysdeps/aarch64/shlib-versions: Move to ... * sysdeps/unix/sysv/linux/aarch64/shlib-versions: ... here. * sysdeps/alpha/shlib-versions: Move to ... * sysdeps/unix/sysv/linux/alpha/shlib-versions: ... here. * sysdeps/arm/shlib-versions: Move to ... * sysdeps/unix/sysv/linux/arm/shlib-versions: ... here. * sysdeps/hppa/shlib-versions: Move all contents except for libgcc_s entry to ... * sysdeps/unix/sysv/linux/hppa/shlib-versions: ... here. Merge in entry from ... * sysdeps/hppa/nptl/shlib-versions: ... here. Remove file. * sysdeps/ia64/shlib-versions: Move to ... * sysdeps/unix/sysv/linux/ia64/shlib-versions: ... here. Merge in entry from ... * sysdeps/ia64/nptl/shlib-versions: ... here. Remove file. * sysdeps/m68k/coldfire/shlib-versions: Move to ... * sysdeps/unix/sysv/linux/m68k/coldfire/shlib-versions: ... here. * sysdeps/microblaze/shlib-versions: Move to ... * sysdeps/unix/sysv/linux/microblaze/shlib-versions: ... here. * sysdeps/mips/shlib-versions: Move to ... * sysdeps/unix/sysv/linux/mips/shlib-versions: ... here. Merge in entry from ... * sysdeps/mips/nptl/shlib-versions: ... here. Remove file. * sysdeps/tile/shlib-versions: Move to ... * sysdeps/unix/sysv/linux/tile/shlib-versions: ... here. * sysdeps/unix/sysv/linux/x86_64/64/shlib-versions: Merge in entry from ... * sysdeps/x86_64/64/shlib-versions: ... here. Remove file. * sysdeps/unix/sysv/linux/x86_64/x32/shlib-versions: Merge in entry from ... * sysdeps/x86_64/x32/shlib-versions: ... here. Remove file. |
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Roland McGrath
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88a4647493 | MIPS: Move NPTL public headers to sysdeps/mips/nptl/. | ||
Roland McGrath
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50f0a637b7 | MIPS: Define TLS_DEFINE_INIT_TP | ||
Andreas Schwab
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774f928582 | Remove second argument from TLS_INIT_TP macro | ||
Roland McGrath
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e0db65176f | Clean up __exit_thread. | ||
Roland McGrath
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498a22333b | Compile with -Wundef. | ||
Joseph Myers
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2ad7600be7 |
Move mips from ports to libc.
I've moved the MIPS port from ports to the main sysdeps hierarchy. Beyond the README update, the move of the files was simply git mv ports/sysdeps/mips sysdeps/mips git mv ports/sysdeps/unix/mips sysdeps/unix/mips git mv ports/sysdeps/unix/sysv/linux/mips sysdeps/unix/sysv/linux/mips and in addition to the ChangeLog entries here, I put a note at the top of ports/ChangeLog.mips similar to those in other files. Tested that disassembly of installed shared libraries for mips is the same before and after this patch (except for ld.so where paths in assertions are involved, as for arm). * sysdeps/mips: Move directory from ports/sysdeps/mips. * sysdeps/unix/mips: Move directory from ports/sysdeps/unix/mips. * sysdeps/unix/sysv/linux/mips: Move directory from ports/sysdeps/unix/sysv/linux/mips. * README: Update listing for mips-*-linux-gnu and mips64-*-linux-gnu. * sysdeps/mips: Move directory to ../sysdeps/mips. * sysdeps/unix/mips: Move directory to ../sysdeps/unix/mips. * sysdeps/unix/sysv/linux/mips: Move directory to ../sysdeps/unix/sysv/linux/mips. |