Added support for TX lock elision of pthread mutexes on s390 and
s390x. This may improve lock scaling of existing programs on TX
capable systems. The lock elision code is only built with
--enable-lock-elision=yes and then requires a GCC version supporting
the TX builtins. With lock elision default mutexes are elided via
__builtin_tbegin, if the cpu supports transactions. By default lock
elision is not enabled and the elision code is not built.
This patch removes the arch specific powerpc implementation and instead
uses the linux default one. Although the current powerpc implementation
already constains the required memory barriers for correct
initialization, the default implementation shows a better performance on
newer chips.
[BZ #15215] This unifies various pthread_once architecture-specific
implementations which were using the same algorithm with slightly different
implementations. It also adds missing memory barriers that are required for
correctness.
This patch moves the __PTHREAD_SPINS definition to arch specific header
since pthread_mutex_t layout is also arch specific. This leads to no
need to defining __PTHREAD_MUTEX_HAVE_ELISION and thus removing of the
undefined compiler warning.
When profiling programs with lock problems with perf record -g dwarf,
libunwind can currently not backtrace through the futex and unlock
functions in pthread. This is because they use out of line sections,
and those are not correctly described in dwarf2 (I believe needs
dwarf3 or 4).
This patch first removes the out of line sections. They only save a
single jump, but cause a lot of pain. Then it converts the now inline
lock code to use the now standard gas .cfi_* commands.
With these changes libunwind/perf can backtrace through the futex
functions now.
Longer term it would be likely better to just use C futex() functions
on x86 like all the other architectures. This would clean the code up
even more.
ChangeLog:
2014-03-17 Will Newton <will.newton@linaro.org>
* nptl/sysdeps/pthread/pthread.h: Check
__PTHREAD_MUTEX_HAVE_ELISION is defined before testing
its value.
We got rid of LinuxThreads in 2005, but we didn't remove
__LT_SPINLOCK_INIT back then. Do it now.
* nptl/sysdeps/pthread/bits/libc-lockP.h [defined NOT_IN_libc
&& !defined IS_IN_libpthread && __LT_SPINNOCK_INIT != 0]:
Remove.
Support for /proc/self/task/$tid/comm as added in Linux 2.6.33,
therefore since the test tst-setgetname relies on this functionality
to operate we must skip the test in kernels < 2.6.33. We wrap the
checks with __ASSUME_PROC_PID_TASK_COMM such that in the future when
we move arch_minimum_kernel to 2.6.33 we can remove this code.
This commit adds a testcase for pthread_setname_np
and pthread_getname_np. The testcase itself has
four tests to validate that these functions work
as expected. The test is only enabled for Linux
since it requires access to an alternate method
for validating the functions work.
This updates glibc for the changes in the ELFv2 relating to the
stack frame layout. These are described in more detail here:
http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01149.htmlhttp://gcc.gnu.org/ml/gcc-patches/2013-11/msg01146.html
Specifically, the "compiler and linker doublewords" were removed,
which has the effect that the save slot for the TOC register is
now at offset 24 rather than 40 to the stack pointer.
In addition, a function may now no longer necessarily assume that
its caller has set up a 64-byte register save area its use.
To address the first change, the patch goes through all assembler
files and replaces immediate offsets in instructions accessing the
ABI-defined stack slots by symbolic offsets. Those already were
defined in ucontext_i.sym and used in some of the context routines,
but that doesn't really seem like the right place for those defines.
The patch instead defines those symbolic offsets in sysdeps.h,
in two variants for the old and new ABI, and uses them systematically
in all assembler files, not just the context routines.
The second change only affected a few assembler files that used
the save area to temporarily store some registers. In those
cases where this happens within a leaf function, this patch
changes the code to store those registers to the "red zone"
below the stack pointer. Otherwise, the functions already allocate
a stack frame, and the patch changes them to add extra space in
these frames as temporary space for the ELFv2 ABI.
The TCB header on Intel contains a field __private_ss that is used
to efficiently implement the -fsplit-stack GCC feature.
In order to prepare for a possible future implementation of that
feature on powerpc64, we'd like to reserve a similar field in
the TCB header as well. (It would be good if this went in with
or before the ELFv2 patches to ensure that this field will be
available always in the ELFv2 environment.)
The field needs to be added at the front of tcbhead_t structure
to avoid changing the ABI; see the recent discussion when adding
the EBB fields.
Autoconf has been deprecating configure.in for quite a long time.
Rename all our configure.in and preconfigure.in files to .ac.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
http://sourceware.org/ml/libc-alpha/2013-08/msg00090.html
This patch fixes symbol versioning in setjmp/longjmp. The existing
code uses raw versions, which results in wrong symbol versioning when
you want to build glibc with a base version of 2.19 for LE.
Note that the merging the 64-bit and 32-bit versions in novmx-lonjmp.c
and pt-longjmp.c doesn't result in GLIBC_2.0 versions for 64-bit, due
to the base in shlib_versions.
* sysdeps/powerpc/longjmp.c: Use proper symbol versioning macros.
* sysdeps/powerpc/novmx-longjmp.c: Likewise.
* sysdeps/powerpc/powerpc32/bsd-_setjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/bsd-setjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/fpu/__longjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/fpu/setjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/mcount.c: Likewise.
* sysdeps/powerpc/powerpc32/setjmp.S: Likewise.
* sysdeps/powerpc/powerpc64/setjmp.S: Likewise.
* nptl/sysdeps/unix/sysv/linux/powerpc/pt-longjmp.c: Likewise.
