With TLE enabled, the adapt count variable update incurs
an 8% overhead before entering the critical section of an
elided mutex.
Instead, if it is done right after leaving the critical
section, this serialization can be avoided.
This alters the existing behavior of __lll_trylock_elision
as it will only decrement the adapt_count if it successfully
acquires the lock.
* sysdeps/unix/sysv/linux/powerpc/elision-lock.c
(__lll_lock_elision): Remove adapt_count decrement...
* sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
(__lll_trylock_elision): Likewise.
* sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
(__lll_unlock_elision): ... to here. And utilize
new adapt_count parameter.
* sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
(__lll_unlock_elision): Update to include adapt_count
parameter.
(lll_unlock_elision): Pass pointer to adapt_count
variable.
Adding this parameter will give architectures more freedom in
how they choose to update this variable. This change has no
effect on architectures which choose not to use it.
* nptl/pthread_mutex_unlock.c(lll_unlock_elision):
Add elision adapt_count parameter to list of arguments.
* sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
(lll_unlock_elision): Update with new parameter list
* sysdeps/unix/sysv/linux/s390/lowlevellock.h
(lll_unlock_elision): Likewise
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
(lll_unlock_elision): Likewise
Only i386 implements epoll_pwait in assembly code withot cancellation
support. All other architectures implement epoll_pwait in epoll_pwait.c
with
int epoll_pwait (int epfd, struct epoll_event *events,
int maxevents, int timeout,
const sigset_t *set)
{
return SYSCALL_CANCEL (epoll_pwait, epfd, events, maxevents,
timeout, set, _NSIG / 8);
}
Although there is no test for epoll_pwait in glibc, since SYSCALL_CANCEL
works on i386 and epoll_pwait.c works for other architectures, it is
safe to assume that epoll_pwait.c with SYSCALL_CANCEL also works on
i386.
[BZ #19137]
* sysdeps/unix/sysv/linux/i386/Makefile (CFLAGS-epoll_pwait.c):
Add -fomit-frame-pointer.
* sysdeps/unix/sysv/linux/i386/epoll_pwait.S: Remove file.
This patch adds an internal entry for __sched_getaffinity_new so that
__sched_getaffinity_old calls __sched_getaffinity_new without going
through PLT.
[BZ #18822]
* sysdeps/unix/sysv/linux/sched_getaffinity.c
(__sched_getaffinity_new): Add libc_hidden_proto and
libc_hidden_def.
Linker in binutils 2.26 and newer generate GOT references instead
PLT references when -z now is passed to linker. We need to extend
scripts/localplt.awk to allow PLT or GOT references.
[BZ #19007]
* scripts/localplt.awk: Also allow GOT references.
* sysdeps/unix/sysv/linux/i386/localplt.data: Mark
_Unwind_Find_FDE, calloc, memalign, realloc and __libc_memalign
with "+ REL R_386_GLOB_DAT".
* sysdeps/x86_64/localplt.data: Mark calloc, memalign, realloc
and __libc_memalign with "+ RELA R_X86_64_GLOB_DAT".
This patch uses INTERNAL_SYSCALL and INLINE_SYSCALL_ERROR_RETURN_VALUE
to avoid reading and writing errno directly so that we don't need to
call __x86.get_pc_thunk.reg to load PC into reg in case there is an
error.
* sysdeps/unix/sysv/linux/i386/brk.c (__brk): Use
INLINE_SYSCALL_ERROR_RETURN_VALUE.
* sysdeps/unix/sysv/linux/i386/fxstatat.c (__fxstatat):
Likewise.
* sysdeps/unix/sysv/linux/i386/setegid.c (setegid): Likewise.
* sysdeps/unix/sysv/linux/i386/seteuid.c (seteuid): Likewise.
* sysdeps/unix/sysv/linux/i386/fxstat.c (__fxstat): Use
INTERNAL_SYSCALLINTERNAL_SYSCALL and
INLINE_SYSCALL_ERROR_RETURN_VALUE.
* sysdeps/unix/sysv/linux/i386/lockf64.c (lockf64): Likewise.
* sysdeps/unix/sysv/linux/i386/lxstat.c (__lxstat): Likewise.
* sysdeps/unix/sysv/linux/i386/sigaction.c (__libc_sigaction):
Likewise.
* sysdeps/unix/sysv/linux/i386/xstat.c (__xstat): Likewise.
This patch sets lseek/llseek for 64-bit, MIPS n32, and x86_32 as non-
cancelable. This make it consistant with 32-bit platform.
Tested on i686, x86_64, and x32.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (lseek): Set as
non-cancelable.
* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list (llseek): Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/lseek.S (__libc_lseek64):
Likewise.
Since we require a new enough kernel all the time, the __ASSUME_FDATASYNC
define has been hardcoded to 1. That means we can delete the alpha file
for fdatasync now and rely on the syscalls list like other ports.
Profiling git's test suite, Linus noted [1] that a disproportionately
large amount of time was spent reading /proc/meminfo. This is done by
the glibc functions get_phys_pages and get_avphys_pages, but they only
need the MemTotal and MemFree fields, respectively. That same
information can be obtained with a single syscall, sysinfo, instead of
six: open, fstat, mmap, read, close, munmap. While sysinfo also
provides more than necessary, it does a lot less work than what the
kernel needs to do to provide the entire /proc/meminfo. Both strace -T
and in-app microbenchmarks shows that the sysinfo() approach is
roughly an order of magnitude faster.
sysinfo() is much older than what glibc currently requires, so I don't
think there's any reason to keep the old parsing code. Moreover, this
makes get_[av]phys_pages work even in the absence of /proc.
Linus noted that something as simple as 'bash -c "echo"' would trigger
the reading of /proc/meminfo, but gdb says that many more applications
than just bash are affected:
Starting program: /bin/bash "-c" "echo"
Breakpoint 1, __get_phys_pages () at ../sysdeps/unix/sysv/linux/getsysstats.c:283
283 ../sysdeps/unix/sysv/linux/getsysstats.c: No such file or directory.
(gdb) bt
So it seems that any application that uses qsort on a moderately sized
array will incur this cost (once), which is obviously proportionately
more expensive for lots of short-lived processes (such as the git test
suite).
[1] http://thread.gmane.org/gmane.linux.kernel/2019285
Signed-off-by: Rasmus Villemoes <rv@rasmusvillemoes.dk>
* sysdeps/unix/sysv/linux/getsysstats.c (__get_phys_pages):
Use sysinfo system call instead of parsing /proc/meminfo.
* sysdeps/unix/sysv/linux/getsysstats.c (__get_avphys_pages):
Likewise.
It was noted in
<https://sourceware.org/ml/libc-alpha/2012-09/msg00305.html> that the
bits/*.h naming scheme should only be used for installed headers.
This patch renames bits/atomic.h to atomic-machine.h to follow that
convention.
This is the only change in this series that needs to change the
filename rather than simply removing a directory level (because both
atomic.h and bits/atomic.h exist at present).
Tested for x86_64 (testsuite, and that installed stripped shared
libraries are unchanged by the patch).
[BZ #14912]
* sysdeps/aarch64/bits/atomic.h: Move to ...
* sysdeps/aarch64/atomic-machine.h: ...here.
(_AARCH64_BITS_ATOMIC_H): Rename macro to
_AARCH64_ATOMIC_MACHINE_H.
* sysdeps/alpha/bits/atomic.h: Move to ...
* sysdeps/alpha/atomic-machine.h: ...here.
* sysdeps/arm/bits/atomic.h: Move to ...
* sysdeps/arm/atomic-machine.h: ...here. Update comments.
* bits/atomic.h: Move to ...
* sysdeps/generic/atomic-machine.h: ...here.
(_BITS_ATOMIC_H): Rename macro to _ATOMIC_MACHINE_H.
* sysdeps/i386/bits/atomic.h: Move to ...
* sysdeps/i386/atomic-machine.h: ...here.
* sysdeps/ia64/bits/atomic.h: Move to ...
* sysdeps/ia64/atomic-machine.h: ...here.
* sysdeps/m68k/coldfire/bits/atomic.h: Move to ...
* sysdeps/m68k/coldfire/atomic-machine.h: ...here.
(_BITS_ATOMIC_H): Rename macro to _ATOMIC_MACHINE_H.
* sysdeps/m68k/m680x0/m68020/bits/atomic.h: Move to ...
* sysdeps/m68k/m680x0/m68020/atomic-machine.h: ...here.
* sysdeps/microblaze/bits/atomic.h: Move to ...
* sysdeps/microblaze/atomic-machine.h: ...here.
* sysdeps/mips/bits/atomic.h: Move to ...
* sysdeps/mips/atomic-machine.h: ...here.
(_MIPS_BITS_ATOMIC_H): Rename macro to _MIPS_ATOMIC_MACHINE_H.
* sysdeps/powerpc/bits/atomic.h: Move to ...
* sysdeps/powerpc/atomic-machine.h: ...here. Update comments.
* sysdeps/powerpc/powerpc32/bits/atomic.h: Move to ...
* sysdeps/powerpc/powerpc32/atomic-machine.h: ...here. Update
comments. Include <atomic-machine.h> instead of <bits/atomic.h>.
* sysdeps/powerpc/powerpc64/bits/atomic.h: Move to ...
* sysdeps/powerpc/powerpc64/atomic-machine.h: ...here. Include
<atomic-machine.h> instead of <bits/atomic.h>.
* sysdeps/s390/bits/atomic.h: Move to ...
* sysdeps/s390/atomic-machine.h: ...here.
* sysdeps/sparc/sparc32/bits/atomic.h: Move to ...
* sysdeps/sparc/sparc32/atomic-machine.h: ...here.
(_BITS_ATOMIC_H): Rename macro to _ATOMIC_MACHINE_H.
* sysdeps/sparc/sparc32/sparcv9/bits/atomic.h: Move to ...
* sysdeps/sparc/sparc32/sparcv9/atomic-machine.h: ...here.
* sysdeps/sparc/sparc64/bits/atomic.h: Move to ...
* sysdeps/sparc/sparc64/atomic-machine.h: ...here.
* sysdeps/tile/bits/atomic.h: Move to ...
* sysdeps/tile/atomic-machine.h: ...here.
* sysdeps/tile/tilegx/bits/atomic.h: Move to ...
* sysdeps/tile/tilegx/atomic-machine.h: ...here. Include
<sysdeps/tile/atomic-machine.h> instead of
<sysdeps/tile/bits/atomic.h>.
(_BITS_ATOMIC_H): Rename macro to _ATOMIC_MACHINE_H.
* sysdeps/tile/tilepro/bits/atomic.h: Move to ...
* sysdeps/tile/tilepro/atomic-machine.h: ...here. Include
<sysdeps/tile/atomic-machine.h> instead of
<sysdeps/tile/bits/atomic.h>.
(_BITS_ATOMIC_H): Rename macro to _ATOMIC_MACHINE_H.
* sysdeps/unix/sysv/linux/arm/bits/atomic.h: Move to ...
* sysdeps/unix/sysv/linux/arm/atomic-machine.h: ...here. Include
<sysdeps/arm/atomic-machine.h> instead of
<sysdeps/arm/bits/atomic.h>.
* sysdeps/unix/sysv/linux/hppa/bits/atomic.h: Move to ...
* sysdeps/unix/sysv/linux/hppa/atomic-machine.h: ...here.
(_BITS_ATOMIC_H): Rename macro to _ATOMIC_MACHINE_H.
* sysdeps/unix/sysv/linux/m68k/coldfire/bits/atomic.h: Move to ...
* sysdeps/unix/sysv/linux/m68k/coldfire/atomic-machine.h: ...here.
(_BITS_ATOMIC_H): Rename macro to _ATOMIC_MACHINE_H.
* sysdeps/unix/sysv/linux/nios2/bits/atomic.h: Move to ...
* sysdeps/unix/sysv/linux/nios2/atomic-machine.h: ...here.
(_NIOS2_BITS_ATOMIC_H): Rename macro to _NIOS2_ATOMIC_MACHINE_H.
* sysdeps/unix/sysv/linux/sh/bits/atomic.h: Move to ...
* sysdeps/unix/sysv/linux/sh/atomic-machine.h: ...here.
* sysdeps/x86_64/bits/atomic.h: Move to ...
* sysdeps/x86_64/atomic-machine.h: ...here.
* include/atomic.h: Include <atomic-machine.h> instead of
<bits/atomic.h>.
Commit f4491417cc introduced some warnings
when building GLIBC with GCC 5.x. similar to those fixed by commit
dd6e8af6ba. This patch fixes those warnings.
* sysdeps/unix/sysv/linux/socketpair.c: Use the address of the
first member of struct sv in syscall macro.
It was noted in
<https://sourceware.org/ml/libc-alpha/2012-09/msg00305.html> that the
bits/*.h naming scheme should only be used for installed headers.
This patch renames bits/m68k-vdso.h to plain m68k-vdso.h to follow
that convention.
[BZ #14912]
* sysdeps/unix/sysv/linux/m68k/bits/m68k-vdso.h: Move to ...
* sysdeps/unix/sysv/linux/m68k/m68k-vdso.h: ...here.
* sysdeps/unix/sysv/linux/m68k/coldfire/bits/atomic.h: Include
<m68k-vdso.h> instead of <bits/m68k-vdso.h>.
* sysdeps/unix/sysv/linux/m68k/init-first.c: Likewise.
* sysdeps/unix/sysv/linux/m68k/m68k-helpers.S: Likewise.
* sysdeps/unix/sysv/linux/m68k/m68k-vdso.c: Likewise.
This patch adds new constants from Linux 4.2 to netinet/in.h:
IPPROTO_MPLS and IP_BIND_ADDRESS_NO_PORT (both in
include/uapi/linux/in.h in Linux; one directly in netinet/in.h, one in
bits/in.h in glibc).
Tested for x86_64 (testsuite, and that installed stripped shared
libraries are unchanged by the patch).
* inet/netinet/in.h (IPPROTO_MPLS): New enum value and macro.
* sysdeps/unix/sysv/linux/bits/in.h (IP_BIND_ADDRESS_NO_PORT): New
macro.
This patch fixes the default wordsize-32 mmap implementation offset
calculation for negative values. Current code uses signed shift
operation to calculate the multiple size to use with syscall and
it is implementation defined. Change it to use a division base
on mmap page size (default being as before, 4096).
Tested on armv7hf.
[BZ #18877]
* posix/Makefile (tests): Add tst-mmap-offset.
* posix/tst-mmap.c: New file.
* sysdeps/unix/sysv/linux/generic/wordsize-32/mmap.c (__mmap): Fix
offset calculation for negative values.
Power ISA 2.07B section B.5.5 relaxed the barrier requirement around a
TLE enabled lock. It is now identical to a traditional lock.
2015-08-26 Paul E. Murphy <murphyp@linux.vnet.ibm.com>
* sysdeps/unix/sysv/linux/powerpc/elision-lock.c
(__arch_compare_and_exchange_val_32_acq): Remove and use common
definition. ISA 2.07B no longer requires full sync.
The HWCAP_S390_VX flag in hwcap field of auxiliary vector indicates
if the vector facility is available and the kernel is aware of it.
This can be tested with LD_SHOW_AUXV=1 <prog>.
Currently it does not show te, because it was not incremented
by commit "S/390: Add hwcap value for transactional execution.".
Thus _DL_HWCAP_COUNT is incremented by two.
ChangeLog:
* sysdeps/s390/dl-procinfo.c (_dl_s390_platforms): Add vector flag.
* sysdeps/s390/dl-procinfo.h: Add vector capability.
* sysdeps/unix/sysv/linux/s390/bits/hwcap.h (HWCAP_S390_VX): Define.
Since _dl_x86_64_save_sse and _dl_x86_64_restore_sse are removed now,
we don't need to run tst-getpid2 with LD_BIND_NOW=1.
[BZ #11214]
* sysdeps/unix/sysv/linux/Makefile (tst-getpid2-ENV): Removed.
Explicit system calls for the socket operations were added in Linux kernel
in commit 86250b9d12ca for powerpc. This patch make use of those instead of
calling socketcall to save number of cycles on networking syscalls.
2015-08-25 Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
* sysdeps/unix/sysv/linux/powerpc/kernel-features.h: Define new macros.
* sysdeps/unix/sysv/linux/accept.c: Call direct system call.
* sysdeps/unix/sysv/linux/bind.c: Call direct system call.
* sysdeps/unix/sysv/linux/connect.c: Call direct system call.
* sysdeps/unix/sysv/linux/getpeername.c: Call direct system call.
* sysdeps/unix/sysv/linux/getsockname.c: Call direct system call.
* sysdeps/unix/sysv/linux/getsockopt.c: Call direct system call.
* sysdeps/unix/sysv/linux/listen.c: Call direct system call.
* sysdeps/unix/sysv/linux/recv.c: Call direct system call.
* sysdeps/unix/sysv/linux/recvfrom.c: Call direct system call.
* sysdeps/unix/sysv/linux/recvmsg.c: Call direct system call.
* sysdeps/unix/sysv/linux/send.c: Call direct system call.
* sysdeps/unix/sysv/linux/sendmsg.c: Call direct system call.
* sysdeps/unix/sysv/linux/sendto.c: Call direct system call.
* sysdeps/unix/sysv/linux/setsockopt.c: Call direct system call.
* sysdeps/unix/sysv/linux/shutdown.c: Call direct system call.
* sysdeps/unix/sysv/linux/socket.c: Call direct system call.
* sysdeps/unix/sysv/linux/socketpair.c: Call direct system call.
Fix usage of tabort in generated syscalls. r0 has special meaning
when used with this instruction, thus it will not generate
persistent errors, nor return an error code. This mitigates poor
CPU usage when performing elided critical sections.
Additionally, transactions should be aborted when entering a user
invoked syscall. Otherwise the results of the transaction may be
undefined.
2015-08-25 Paul E. Murphy <murphyp@linux.vnet.ibm.com>
* sysdeps/powerpc/powerpc32/sysdep.h (ABORT_TRANSACTION): Use
register other than r0 for tabort, it has special meaning.
* sysdeps/powerpc/powerpc64/sysdep.h (ABORT_TRANSACTION): Likewise
* sysdeps/unix.sysv/linux/powerpc/syscall.S (syscall): Abort
transaction before starting syscall.
PowerPC has always used __IPC_64 like most other architectures, which
means that __ASSUME_IPC64 can be always true. Also, all other
architecture implementations that use the ipc syscall are effectively
identical to the generic version and can be removed.
Move sysdeps/x86_64/multiarch/init-arch.h to sysdeps/x86/init-arch.h
which can be used for both i386 and x86_64.
* sysdeps/i386/i686/multiarch/init-arch.h: Removed.
* sysdeps/unix/sysv/linux/x86/init-arch.h: Likewise.
* sysdeps/x86_64/cacheinfo.c: Include <init-arch.h> instead
of "multiarch/init-arch.h".
* sysdeps/x86_64/multiarch/init-arch.h: Renamed to ...
* sysdeps/x86/init-arch.h: This.
Both files include sysdeps/x86_64/multiarch/init-arch.c which has been
removed.
* sysdeps/i386/i686/multiarch/init-arch.c: Removed.
* sysdeps/unix/sysv/linux/x86/init-arch.c: Likewise.
__xstat_conv, __xstat64_conv and __xstat32_conv are internal to glibc.
They should be marked as hidden so that they can't be called without
PLT.
[BZ #18822]
* sysdeps/unix/sysv/linux/xstatconv.h (__xstat_conv): Add
attribute_hidden.
(__xstat64_conv): Likewise.
(__xstat32_conv): Likewise.
Since _dl_x86_cpu_features is always available, we can use x86-64
cacheinfo.c and sysconf.c for both i386 and x86-64.
* sysdeps/i386/i686/Makefile
[$(subdir) == string] (sysdep_routines): Moved to ...
* sysdeps/i386/Makefile: Here.
* sysdeps/i386/i686/cacheinfo.c: Moved to ...
* sysdeps/i386/cacheinfo.c: Here.
* sysdeps/unix/sysv/linux/i386/sysconf.c: Removed.
* sysdeps/unix/sysv/linux/i386/i686/sysconf.c: Likewise.
* sysdeps/unix/sysv/linux/x86_64/sysconf.c: Moved to ...
* sysdeps/unix/sysv/linux/x86/sysconf.c: Here.
