From patchwork Tue May 24 19:07:04 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella X-Patchwork-Id: 12499 Received: (qmail 51688 invoked by alias); 24 May 2016 19:07:20 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 51660 invoked by uid 89); 24 May 2016 19:07:19 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:7997, 2197, 219, 7, cancellation X-HELO: mail-yw0-f169.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=bkQpeUIEnbZE8oAb3JL+k3X/eTEBQx8+qcMPkAgxVIE=; b=Lr/E5QsdA7+dBvQcIB/889ZpxXgZls3eyMuSTv1TEW30QMyWnHIxoJOgymRf+ZOi1h /uugR1lLlc1ACn/TFwlI8pKyc1R8DDHcfmY/Q+4BtrIfOiYG0uZP+IsuX/SSe8xtGcKa GYRgXjj/uamx5zXmv9STKZj7+peLLEm0TkhZ4ktSLFcuBcc5ui9yN76AVWPuiihw1IW3 Cqj+4jko9dgkRfCLUhM1tKR9nGq4nPePwYx6d9M4WxHVNM3NKPM0tPpW4NUH74XF7Rwf uwlDOET8c7kiW/7QpHzcA+y/eo7vlzf5vULNQGAHD30eh+o2uWRpOGBKNGdl12C6gXW/ hxKA== X-Gm-Message-State: ALyK8tK+U0lfRk4wKCtc0IwIS5NsfocpsXCTCVIg+SY5eDixEqF2PWz5PC/dMVu8qOdJjOUh X-Received: by 10.129.87.208 with SMTP id l199mr3466305ywb.312.1464116827481; Tue, 24 May 2016 12:07:07 -0700 (PDT) Subject: Re: [PATCH 3/3] Add runtime check for __ASSUME_REQUEUE_PI (BZ#18463) To: libc-alpha@sourceware.org References: <1463608638-7215-1-git-send-email-adhemerval.zanella@linaro.org> <1463608638-7215-3-git-send-email-adhemerval.zanella@linaro.org> From: Adhemerval Zanella Message-ID: <5744A658.7030904@linaro.org> Date: Tue, 24 May 2016 16:07:04 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <1463608638-7215-3-git-send-email-adhemerval.zanella@linaro.org> I am sending a new version of this patch because now prio_inherit_missing is non longer static inline function, its name causes namespace pollution. Main change from previous version is just the new name scheme by prepending a double underscore. --- Tested on ARM (v3.8 kernel) and x86_64. * nptl/pthreadP.h (prio_inherit_missing): Change name to __prio_inherit_missing. (USE_REQUEUE_PI): Remove define. (use_requeue_pi): New function. * nptl/pthread_cond_broadcast.c [__ASSUME_REQUEUE_PI] (__pthread_cond_broadcast): Remove ifdef. (USE_REQUEUE_PI): Change to use_requeue_pi. * nptl/pthread_cond_signal.c [__ASSUME_REQUEUE_PI] (__pthread_cond_signal): Remove ifdef. (USE_REQUEUE_PI): Change to use_requeue_pi. * nptl/pthread_cond_timedwait.c [__ASSUME_REQUEUE_PI] (__pthread_cond_timedwait): Remove ifdef. (USE_REQUEUE_PI): Change to use_requeue_pi. ( nptl/pthread_cond_wait.c [__ASSUME_REQUEUE_PI] (__pthread_cond_wait): Remove ifdef. (USE_REQUEUE_PI): Change to use_requeue_pi. * nptl/pthread_mutex_init.c (prio_inherit_missing): Remove 'static' qualifier and change name to __prio_inherit_missing. --- nptl/pthreadP.h | 23 ++++++++++++++--------- nptl/pthread_cond_broadcast.c | 5 ++--- nptl/pthread_cond_signal.c | 5 ++--- nptl/pthread_cond_timedwait.c | 11 ++++------- nptl/pthread_cond_wait.c | 13 +++++-------- nptl/pthread_mutex_init.c | 7 ++++--- 7 files changed, 50 insertions(+), 33 deletions(-) diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h index d479a3e..e53f649 100644 --- a/nptl/pthreadP.h +++ b/nptl/pthreadP.h @@ -585,17 +585,22 @@ extern void __wait_lookup_done (void) attribute_hidden; # define PTHREAD_STATIC_FN_REQUIRE(name) __asm (".globl " #name); #endif +extern bool prio_inherit_missing (void); + /* Test if the mutex is suitable for the FUTEX_WAIT_REQUEUE_PI operation. */ -#if (defined lll_futex_wait_requeue_pi \ - && defined __ASSUME_REQUEUE_PI) -# define USE_REQUEUE_PI(mut) \ - ((mut) && (mut) != (void *) ~0l \ - && (((mut)->__data.__kind \ - & (PTHREAD_MUTEX_PRIO_INHERIT_NP | PTHREAD_MUTEX_ROBUST_NORMAL_NP)) \ - == PTHREAD_MUTEX_PRIO_INHERIT_NP)) -#else -# define USE_REQUEUE_PI(mut) 0 +static inline bool +use_requeue_pi (pthread_mutex_t *mut) +{ +#ifndef __ASSUME_REQUEUE_PI + if (__prio_inherit_missing ()) + return false; #endif + return (mut) && + (mut) != (void *) ~0l && + (((mut)->__data.__kind + & (PTHREAD_MUTEX_PRIO_INHERIT_NP | PTHREAD_MUTEX_ROBUST_NORMAL_NP)) == + PTHREAD_MUTEX_PRIO_INHERIT_NP); +} /* Returns 0 if POL is a valid scheduling policy. */ static inline int diff --git a/nptl/pthread_cond_broadcast.c b/nptl/pthread_cond_broadcast.c index 552fd42..ef81bcd 100644 --- a/nptl/pthread_cond_broadcast.c +++ b/nptl/pthread_cond_broadcast.c @@ -60,9 +60,8 @@ __pthread_cond_broadcast (pthread_cond_t *cond) || PTHREAD_MUTEX_PSHARED (mut) & PTHREAD_MUTEX_PSHARED_BIT) goto wake_all; -#if (defined lll_futex_cmp_requeue_pi \ - && defined __ASSUME_REQUEUE_PI) - if (USE_REQUEUE_PI (mut)) +#ifdef lll_futex_cmp_requeue_pi + if (use_requeue_pi (mut)) { if (lll_futex_cmp_requeue_pi (&cond->__data.__futex, 1, INT_MAX, &mut->__data.__lock, futex_val, diff --git a/nptl/pthread_cond_signal.c b/nptl/pthread_cond_signal.c index b3a6d3d..9c8f883 100644 --- a/nptl/pthread_cond_signal.c +++ b/nptl/pthread_cond_signal.c @@ -46,11 +46,10 @@ __pthread_cond_signal (pthread_cond_t *cond) ++cond->__data.__wakeup_seq; ++cond->__data.__futex; -#if (defined lll_futex_cmp_requeue_pi \ - && defined __ASSUME_REQUEUE_PI) +#ifdef lll_futex_cmp_requeue_pi pthread_mutex_t *mut = cond->__data.__mutex; - if (USE_REQUEUE_PI (mut) + if (use_requeue_pi (mut) /* This can only really fail with a ENOSYS, since nobody can modify futex while we have the cond_lock. */ && lll_futex_cmp_requeue_pi (&cond->__data.__futex, 1, 0, diff --git a/nptl/pthread_cond_timedwait.c b/nptl/pthread_cond_timedwait.c index 711a51d..61a651c 100644 --- a/nptl/pthread_cond_timedwait.c +++ b/nptl/pthread_cond_timedwait.c @@ -63,8 +63,7 @@ __pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex, int pshared = (cond->__data.__mutex == (void *) ~0l) ? LLL_SHARED : LLL_PRIVATE; -#if (defined lll_futex_timed_wait_requeue_pi \ - && defined __ASSUME_REQUEUE_PI) +#ifdef lll_futex_timed_wait_requeue_pi int pi_flag = 0; #endif @@ -161,8 +160,7 @@ __pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex, /* REQUEUE_PI was implemented after FUTEX_CLOCK_REALTIME, so it is sufficient to check just the former. */ -#if (defined lll_futex_timed_wait_requeue_pi \ - && defined __ASSUME_REQUEUE_PI) +#ifdef lll_futex_timed_wait_requeue_pi /* If pi_flag remained 1 then it means that we had the lock and the mutex but a spurious waker raced ahead of us. Give back the mutex before going into wait again. */ @@ -171,7 +169,7 @@ __pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex, __pthread_mutex_cond_lock_adjust (mutex); __pthread_mutex_unlock_usercnt (mutex, 0); } - pi_flag = USE_REQUEUE_PI (mutex); + pi_flag = use_requeue_pi (mutex); if (pi_flag) { @@ -250,8 +248,7 @@ __pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex, __pthread_cleanup_pop (&buffer, 0); /* Get the mutex before returning. */ -#if (defined lll_futex_timed_wait_requeue_pi \ - && defined __ASSUME_REQUEUE_PI) +#ifdef lll_futex_timed_wait_requeue_pi if (pi_flag) { __pthread_mutex_cond_lock_adjust (mutex); diff --git a/nptl/pthread_cond_wait.c b/nptl/pthread_cond_wait.c index 3f62acc..f79bf67 100644 --- a/nptl/pthread_cond_wait.c +++ b/nptl/pthread_cond_wait.c @@ -86,7 +86,7 @@ __condvar_cleanup (void *arg) /* Get the mutex before returning unless asynchronous cancellation is in effect. We don't try to get the mutex if we already own it. */ - if (!(USE_REQUEUE_PI (cbuffer->mutex)) + if (!(use_requeue_pi (cbuffer->mutex)) || ((cbuffer->mutex->__data.__lock & FUTEX_TID_MASK) != THREAD_GETMEM (THREAD_SELF, tid))) { @@ -106,8 +106,7 @@ __pthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex) int pshared = (cond->__data.__mutex == (void *) ~0l) ? LLL_SHARED : LLL_PRIVATE; -#if (defined lll_futex_wait_requeue_pi \ - && defined __ASSUME_REQUEUE_PI) +#ifdef lll_futex_wait_requeue_pi int pi_flag = 0; #endif @@ -160,8 +159,7 @@ __pthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex) /* Enable asynchronous cancellation. Required by the standard. */ cbuffer.oldtype = __pthread_enable_asynccancel (); -#if (defined lll_futex_wait_requeue_pi \ - && defined __ASSUME_REQUEUE_PI) +#ifdef lll_futex_wait_requeue_pi /* If pi_flag remained 1 then it means that we had the lock and the mutex but a spurious waker raced ahead of us. Give back the mutex before going into wait again. */ @@ -170,7 +168,7 @@ __pthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex) __pthread_mutex_cond_lock_adjust (mutex); __pthread_mutex_unlock_usercnt (mutex, 0); } - pi_flag = USE_REQUEUE_PI (mutex); + pi_flag = use_requeue_pi (mutex); if (pi_flag) { @@ -221,8 +219,7 @@ __pthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex) __pthread_cleanup_pop (&buffer, 0); /* Get the mutex before returning. Not needed for PI. */ -#if (defined lll_futex_wait_requeue_pi \ - && defined __ASSUME_REQUEUE_PI) +#ifdef lll_futex_wait_requeue_pi if (pi_flag) { __pthread_mutex_cond_lock_adjust (mutex); diff --git a/nptl/pthread_mutex_init.c b/nptl/pthread_mutex_init.c index 6aef890..c37f623 100644 --- a/nptl/pthread_mutex_init.c +++ b/nptl/pthread_mutex_init.c @@ -33,8 +33,9 @@ static const struct pthread_mutexattr default_mutexattr = }; -static bool -prio_inherit_missing (void) +bool +attribute_hidden +__prio_inherit_missing (void) { #ifdef __NR_futex static int tpi_supported; @@ -72,7 +73,7 @@ __pthread_mutex_init (pthread_mutex_t *mutex, break; case PTHREAD_PRIO_INHERIT << PTHREAD_MUTEXATTR_PROTOCOL_SHIFT: - if (__glibc_unlikely (prio_inherit_missing ())) + if (__glibc_unlikely (__prio_inherit_missing ())) return ENOTSUP; break;