diff options
Diffstat (limited to 'nptl/sysdeps/unix/sysv')
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h | 22 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86/Makefile | 3 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86/elision-conf.c | 87 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86/elision-conf.h | 44 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c | 95 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86/elision-timed.c | 26 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c | 72 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86/elision-unlock.c | 33 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86/hle.h | 75 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h | 23 |
10 files changed, 480 insertions, 0 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h index f665ac9e6b..cc3ec5ba26 100644 --- a/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h +++ b/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h @@ -430,6 +430,12 @@ LLL_STUB_UNWIND_INFO_END : "memory"); \ result; }) +extern int __lll_timedlock_elision (int *futex, short *adapt_count, + const struct timespec *timeout, + int private) attribute_hidden; + +#define lll_timedlock_elision(futex, adapt_count, timeout, private) \ + __lll_timedlock_elision(&(futex), &(adapt_count), timeout, private) #define lll_robust_timedlock(futex, timeout, id, private) \ ({ int result, ignore1, ignore2, ignore3; \ @@ -583,6 +589,22 @@ extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime) } \ __result; }) +extern int __lll_lock_elision (int *futex, short *adapt_count, int private) + attribute_hidden; + +extern int __lll_unlock_elision(int *lock, int private) + attribute_hidden; + +extern int __lll_trylock_elision(int *lock, short *adapt_count) + attribute_hidden; + +#define lll_lock_elision(futex, adapt_count, private) \ + __lll_lock_elision (&(futex), &(adapt_count), private) +#define lll_unlock_elision(futex, private) \ + __lll_unlock_elision (&(futex), private) +#define lll_trylock_elision(futex, adapt_count) \ + __lll_trylock_elision(&(futex), &(adapt_count)) + #endif /* !__ASSEMBLER__ */ #endif /* lowlevellock.h */ diff --git a/nptl/sysdeps/unix/sysv/linux/x86/Makefile b/nptl/sysdeps/unix/sysv/linux/x86/Makefile new file mode 100644 index 0000000000..61b7552bc9 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/x86/Makefile @@ -0,0 +1,3 @@ +libpthread-sysdep_routines += init-arch +libpthread-sysdep_routines += elision-lock elision-unlock elision-timed \ + elision-trylock diff --git a/nptl/sysdeps/unix/sysv/linux/x86/elision-conf.c b/nptl/sysdeps/unix/sysv/linux/x86/elision-conf.c new file mode 100644 index 0000000000..6277e48d76 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/x86/elision-conf.c @@ -0,0 +1,87 @@ +/* elision-conf.c: Lock elision tunable parameters. + Copyright (C) 2013 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <pthreadP.h> +#include <init-arch.h> +#include <elision-conf.h> +#include <unistd.h> + +/* Reasonable initial tuning values, may be revised in the future. + This is a conservative initial value. */ + +struct elision_config __elision_aconf = + { + /* How often to not attempt to use elision if a transaction aborted + because the lock is already acquired. Expressed in number of lock + acquisition attempts. */ + .skip_lock_busy = 3, + /* How often to not attempt to use elision if a transaction aborted due + to reasons other than other threads' memory accesses. Expressed in + number of lock acquisition attempts. */ + .skip_lock_internal_abort = 3, + /* How often we retry using elision if there is chance for the transaction + to finish execution (e.g., it wasn't aborted due to the lock being + already acquired. */ + .retry_try_xbegin = 3, + /* Same as SKIP_LOCK_INTERNAL_ABORT but for trylock. */ + .skip_trylock_internal_abort = 3, + }; + +/* Elided rwlock toggle, set when elision is available and is + enabled for rwlocks. */ + +int __rwlock_rtm_enabled attribute_hidden; + +/* Retries for elided rwlocks on read. Conservative initial value. */ + +int __rwlock_rtm_read_retries attribute_hidden = 3; + +/* Set when the CPU supports elision. When false elision is never attempted. */ + +int __elision_available attribute_hidden; + +/* Force elision for all new locks. This is used to decide whether existing + DEFAULT locks should be automatically upgraded to elision in + pthread_mutex_lock(). Disabled for suid programs. Only used when elision + is available. */ + +int __pthread_force_elision attribute_hidden; + +/* Initialize elison. */ + +static void +elision_init (int argc __attribute__ ((unused)), + char **argv __attribute__ ((unused)), + char **environ) +{ + __elision_available = HAS_RTM; + __pthread_force_elision = __libc_enable_secure ? 0 : __elision_available; + __rwlock_rtm_enabled = __libc_enable_secure ? 0 : __elision_available; +} + +#ifdef SHARED +# define INIT_SECTION ".init_array" +#else +# define INIT_SECTION ".preinit_array" +#endif + +void (*const __pthread_init_array []) (int, char **, char **) + __attribute__ ((section (INIT_SECTION), aligned (sizeof (void *)))) = +{ + &elision_init +}; diff --git a/nptl/sysdeps/unix/sysv/linux/x86/elision-conf.h b/nptl/sysdeps/unix/sysv/linux/x86/elision-conf.h new file mode 100644 index 0000000000..55b81db930 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/x86/elision-conf.h @@ -0,0 +1,44 @@ +/* elision-conf.h: Lock elision tunable parameters. + Copyright (C) 2013 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ +#ifndef _ELISION_CONF_H +#define _ELISION_CONF_H 1 + +#include <pthread.h> +#include <cpuid.h> +#include <time.h> + +/* Should make sure there is no false sharing on this. */ + +struct elision_config +{ + int skip_lock_busy; + int skip_lock_internal_abort; + int retry_try_xbegin; + int skip_trylock_internal_abort; +}; + +extern struct elision_config __elision_aconf attribute_hidden; + +extern int __rwlock_rtm_enabled attribute_hidden; +extern int __elision_available attribute_hidden; +extern int __pthread_force_elision attribute_hidden; + +/* Tell the test suite to test elision for this architecture. */ +#define HAVE_ELISION 1 + +#endif diff --git a/nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c b/nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c new file mode 100644 index 0000000000..de16f1b02f --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c @@ -0,0 +1,95 @@ +/* elision-lock.c: Elided pthread mutex lock. + Copyright (C) 2011-2013 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <pthread.h> +#include "pthreadP.h" +#include "lowlevellock.h" +#include "hle.h" +#include <elision-conf.h> + +#if !defined(LLL_LOCK) && !defined(EXTRAARG) +/* Make sure the configuration code is always linked in for static + libraries. */ +#include "elision-conf.c" +#endif + +#ifndef EXTRAARG +#define EXTRAARG +#endif +#ifndef LLL_LOCK +#define LLL_LOCK(a,b) lll_lock(a,b), 0 +#endif + +#define aconf __elision_aconf + +/* Adaptive lock using transactions. + By default the lock region is run as a transaction, and when it + aborts or the lock is busy the lock adapts itself. */ + +int +__lll_lock_elision (int *futex, short *adapt_count, EXTRAARG int private) +{ + if (*adapt_count <= 0) + { + unsigned status; + int try_xbegin; + + for (try_xbegin = aconf.retry_try_xbegin; + try_xbegin > 0; + try_xbegin--) + { + if ((status = _xbegin()) == _XBEGIN_STARTED) + { + if (*futex == 0) + return 0; + + /* Lock was busy. Fall back to normal locking. + Could also _xend here but xabort with 0xff code + is more visible in the profiler. */ + _xabort (_ABORT_LOCK_BUSY); + } + + if (!(status & _XABORT_RETRY)) + { + if ((status & _XABORT_EXPLICIT) + && _XABORT_CODE (status) == _ABORT_LOCK_BUSY) + { + /* Right now we skip here. Better would be to wait a bit + and retry. This likely needs some spinning. */ + if (*adapt_count != aconf.skip_lock_busy) + *adapt_count = aconf.skip_lock_busy; + } + /* Internal abort. There is no chance for retry. + Use the normal locking and next time use lock. + Be careful to avoid writing to the lock. */ + else if (*adapt_count != aconf.skip_lock_internal_abort) + *adapt_count = aconf.skip_lock_internal_abort; + break; + } + } + } + else + { + /* Use a normal lock until the threshold counter runs out. + Lost updates possible. */ + (*adapt_count)--; + } + + /* Use a normal lock here. */ + return LLL_LOCK ((*futex), private); +} diff --git a/nptl/sysdeps/unix/sysv/linux/x86/elision-timed.c b/nptl/sysdeps/unix/sysv/linux/x86/elision-timed.c new file mode 100644 index 0000000000..8825d1287e --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/x86/elision-timed.c @@ -0,0 +1,26 @@ +/* elision-timed.c: Lock elision timed lock. + Copyright (C) 2013 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <time.h> +#include <elision-conf.h> +#include "lowlevellock.h" +#define __lll_lock_elision __lll_timedlock_elision +#define EXTRAARG const struct timespec *t, +#undef LLL_LOCK +#define LLL_LOCK(a, b) lll_timedlock(a, t, b) +#include "elision-lock.c" diff --git a/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c b/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c new file mode 100644 index 0000000000..2939fc9640 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c @@ -0,0 +1,72 @@ +/* elision-trylock.c: Lock eliding trylock for pthreads. + Copyright (C) 2013 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <pthread.h> +#include <pthreadP.h> +#include <lowlevellock.h> +#include "hle.h" +#include <elision-conf.h> + +#define aconf __elision_aconf + +/* Try to elide a futex trylock. FUTEX is the futex variable. TRY_LOCK is the + adaptation counter in the mutex. UPGRADED is != 0 when this is for an + automatically upgraded lock. */ + +int +__lll_trylock_elision (int *futex, short *adapt_count) +{ + /* Implement POSIX semantics by forbiding nesting + trylock. Sorry. After the abort the code is re-executed + non transactional and if the lock was already locked + return an error. */ + _xabort (_ABORT_NESTED_TRYLOCK); + + /* Only try a transaction if it's worth it. */ + if (*adapt_count <= 0) + { + unsigned status; + + if ((status = _xbegin()) == _XBEGIN_STARTED) + { + if (*futex == 0) + return 0; + + /* Lock was busy. Fall back to normal locking. + Could also _xend here but xabort with 0xff code + is more visible in the profiler. */ + _xabort (_ABORT_LOCK_BUSY); + } + + if (!(status & _XABORT_RETRY)) + { + /* Internal abort. No chance for retry. For future + locks don't try speculation for some time. */ + if (*adapt_count != aconf.skip_trylock_internal_abort) + *adapt_count = aconf.skip_trylock_internal_abort; + } + /* Could do some retries here. */ + } + else + { + /* Lost updates are possible, but harmless. */ + (*adapt_count)--; + } + + return lll_trylock (*futex); +} diff --git a/nptl/sysdeps/unix/sysv/linux/x86/elision-unlock.c b/nptl/sysdeps/unix/sysv/linux/x86/elision-unlock.c new file mode 100644 index 0000000000..bb13c6b300 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/x86/elision-unlock.c @@ -0,0 +1,33 @@ +/* elision-unlock.c: Commit an elided pthread lock. + Copyright (C) 2013 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include "pthreadP.h" +#include "lowlevellock.h" +#include "hle.h" + +int +__lll_unlock_elision(int *lock, int private) +{ + /* When the lock was free we're in a transaction. + When you crash here you unlocked a free lock. */ + if (*lock == 0) + _xend(); + else + lll_unlock ((*lock), private); + return 0; +} diff --git a/nptl/sysdeps/unix/sysv/linux/x86/hle.h b/nptl/sysdeps/unix/sysv/linux/x86/hle.h new file mode 100644 index 0000000000..a08f0fa711 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/x86/hle.h @@ -0,0 +1,75 @@ +/* Shared RTM header. Emulate TSX intrinsics for compilers and assemblers + that do not support the intrinsics and instructions yet. */ +#ifndef _HLE_H +#define _HLE_H 1 + +#ifdef __ASSEMBLER__ + +.macro XBEGIN target + .byte 0xc7,0xf8 + .long \target-1f +1: +.endm + +.macro XEND + .byte 0x0f,0x01,0xd5 +.endm + +.macro XABORT code + .byte 0xc6,0xf8,\code +.endm + +.macro XTEST + .byte 0x0f,0x01,0xd6 +.endm + +#endif + +/* Official RTM intrinsics interface matching gcc/icc, but works + on older gcc compatible compilers and binutils. + We should somehow detect if the compiler supports it, because + it may be able to generate slightly better code. */ + +#define _XBEGIN_STARTED (~0u) +#define _XABORT_EXPLICIT (1 << 0) +#define _XABORT_RETRY (1 << 1) +#define _XABORT_CONFLICT (1 << 2) +#define _XABORT_CAPACITY (1 << 3) +#define _XABORT_DEBUG (1 << 4) +#define _XABORT_NESTED (1 << 5) +#define _XABORT_CODE(x) (((x) >> 24) & 0xff) + +#define _ABORT_LOCK_BUSY 0xff +#define _ABORT_LOCK_IS_LOCKED 0xfe +#define _ABORT_NESTED_TRYLOCK 0xfd + +#ifndef __ASSEMBLER__ + +#define __force_inline __attribute__((__always_inline__)) inline + +static __force_inline int _xbegin(void) +{ + int ret = _XBEGIN_STARTED; + asm volatile (".byte 0xc7,0xf8 ; .long 0" : "+a" (ret) :: "memory"); + return ret; +} + +static __force_inline void _xend(void) +{ + asm volatile (".byte 0x0f,0x01,0xd5" ::: "memory"); +} + +static __force_inline void _xabort(const unsigned int status) +{ + asm volatile (".byte 0xc6,0xf8,%P0" :: "i" (status) : "memory"); +} + +static __force_inline int _xtest(void) +{ + unsigned char out; + asm volatile (".byte 0x0f,0x01,0xd6 ; setnz %0" : "=r" (out) :: "memory"); + return out; +} + +#endif +#endif diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h b/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h index 7a176aec38..35fb01a0de 100644 --- a/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h +++ b/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h @@ -427,6 +427,13 @@ LLL_STUB_UNWIND_INFO_END : "memory", "cx", "cc", "r10", "r11"); \ result; }) +extern int __lll_timedlock_elision (int *futex, short *adapt_count, + const struct timespec *timeout, + int private) attribute_hidden; + +#define lll_timedlock_elision(futex, adapt_count, timeout, private) \ + __lll_timedlock_elision(&(futex), &(adapt_count), timeout, private) + #define lll_robust_timedlock(futex, timeout, id, private) \ ({ int result, ignore1, ignore2, ignore3; \ __asm __volatile (LOCK_INSTR "cmpxchgl %1, %4\n\t" \ @@ -597,6 +604,22 @@ extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime) } \ __result; }) +extern int __lll_lock_elision (int *futex, short *adapt_count, int private) + attribute_hidden; + +extern int __lll_unlock_elision (int *lock, int private) + attribute_hidden; + +extern int __lll_trylock_elision (int *lock, short *adapt_count) + attribute_hidden; + +#define lll_lock_elision(futex, adapt_count, private) \ + __lll_lock_elision (&(futex), &(adapt_count), private) +#define lll_unlock_elision(futex, private) \ + __lll_unlock_elision (&(futex), private) +#define lll_trylock_elision(futex, adapt_count) \ + __lll_trylock_elision (&(futex), &(adapt_count)) + #endif /* !__ASSEMBLER__ */ #endif /* lowlevellock.h */ |