From 38cc11daa43b11b12a7774405accee1007de1adf Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 16 Jan 2019 16:22:29 +0000 Subject: nptl: Remove pthread_clock_gettime pthread_clock_settime This patch removes CLOCK_THREAD_CPUTIME_ID and CLOCK_PROCESS_CPUTIME_ID support from clock_gettime and clock_settime generic implementation. For Linux, kernel already provides supports through the syscall and Hurd HTL lacks __pthread_clock_gettime and __pthread_clock_settime internal implementation. As described in clock_gettime man-page [1] on 'Historical note for SMP system', implementing CLOCK_{THREAD,PROCESS}_CPUTIME_ID with timer registers is error-prone and susceptible to timing and accurary issues that the libc can not deal without kernel support. This allows removes unused code which, however, still incur in some runtime overhead in thread creation (the struct pthread cpuclock_offset initialization). If hurd eventually wants to support them it should either either implement as a kernel facility (or something related due its architecture) or in system specific implementation. Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu. I also checked on a i686-gnu build. * nptl/Makefile (libpthread-routines): Remove pthread_clock_gettime and pthread_clock_settime. * nptl/pthreadP.h (__find_thread_by_id): Remove prototype. * elf/dl-support.c [!HP_TIMING_NOAVAIL] (_dl_cpuclock_offset): Remove. (_dl_non_dynamic_init): Remove _dl_cpuclock_offset setting. * elf/rtld.c (_dl_start_final): Likewise. * nptl/allocatestack.c (__find_thread_by_id): Remove function. * sysdeps/generic/ldsodefs.h [!HP_TIMING_NOAVAIL] (_dl_cpuclock_offset): Remove. * sysdeps/mach/hurd/dl-sysdep.c [!HP_TIMING_NOAVAIL] (_dl_cpuclock_offset): Remove. * nptl/descr.h (struct pthread): Rename cpuclock_offset to cpuclock_offset_ununsed. * nptl/nptl-init.c (__pthread_initialize_minimal_internal): Remove cpuclock_offset set. * nptl/pthread_create.c (START_THREAD_DEFN): Likewise. * sysdeps/nptl/fork.c (__libc_fork): Likewise. * nptl/pthread_clock_gettime.c: Remove file. * nptl/pthread_clock_settime.c: Likewise. * sysdeps/unix/clock_gettime.c (hp_timing_gettime): Remove function. [HP_TIMING_AVAIL] (realtime_gettime): Remove CLOCK_THREAD_CPUTIME_ID and CLOCK_PROCESS_CPUTIME_ID support. * sysdeps/unix/clock_settime.c (hp_timing_gettime): Likewise. [HP_TIMING_AVAIL] (realtime_gettime): Likewise. * sysdeps/posix/clock_getres.c (hp_timing_getres): Likewise. [HP_TIMING_AVAIL] (__clock_getres): Likewise. * sysdeps/unix/clock_nanosleep.c (CPUCLOCK_P, INVALID_CLOCK_P): Likewise. (__clock_nanosleep): Remove CPUCLOCK_P and INVALID_CLOCK_P usage. [1] http://man7.org/linux/man-pages/man2/clock_gettime.2.html --- sysdeps/nptl/fork.c | 8 -------- 1 file changed, 8 deletions(-) (limited to 'sysdeps/nptl') diff --git a/sysdeps/nptl/fork.c b/sysdeps/nptl/fork.c index 14b69a6..3f35766 100644 --- a/sysdeps/nptl/fork.c +++ b/sysdeps/nptl/fork.c @@ -83,14 +83,6 @@ __libc_fork (void) if (__fork_generation_pointer != NULL) *__fork_generation_pointer += __PTHREAD_ONCE_FORK_GEN_INCR; -#if HP_TIMING_AVAIL - /* The CPU clock of the thread and process have to be set to zero. */ - hp_timing_t now; - HP_TIMING_NOW (now); - THREAD_SETMEM (self, cpuclock_offset, now); - GL(dl_cpuclock_offset) = now; -#endif - #ifdef __NR_set_robust_list /* Initialize the robust mutex list setting in the kernel which has been reset during the fork. We do not check for errors because if -- cgit v1.1