From 17c78154b0ba2237c37f3e4a95140b754cb6ac8b Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 22 Feb 2022 14:01:49 +0000 Subject: [PATCH] rcu: use coroutine TLS macros RCU may be used from coroutines. Standard __thread variables cannot be used by coroutines. Use the coroutine TLS macros instead. Signed-off-by: Stefan Hajnoczi Message-Id: <20220222140150.27240-4-stefanha@redhat.com> Signed-off-by: Kevin Wolf --- include/qemu/rcu.h | 7 ++++--- tests/unit/rcutorture.c | 10 +++++----- tests/unit/test-rcu-list.c | 4 ++-- util/rcu.c | 10 +++++----- 4 files changed, 16 insertions(+), 15 deletions(-) diff --git a/include/qemu/rcu.h b/include/qemu/rcu.h index e69efbd47f..b063c6fde8 100644 --- a/include/qemu/rcu.h +++ b/include/qemu/rcu.h @@ -29,6 +29,7 @@ #include "qemu/atomic.h" #include "qemu/notify.h" #include "qemu/sys_membarrier.h" +#include "qemu/coroutine-tls.h" #ifdef __cplusplus extern "C" { @@ -76,11 +77,11 @@ struct rcu_reader_data { NotifierList force_rcu; }; -extern __thread struct rcu_reader_data rcu_reader; +QEMU_DECLARE_CO_TLS(struct rcu_reader_data, rcu_reader) static inline void rcu_read_lock(void) { - struct rcu_reader_data *p_rcu_reader = &rcu_reader; + struct rcu_reader_data *p_rcu_reader = get_ptr_rcu_reader(); unsigned ctr; if (p_rcu_reader->depth++ > 0) { @@ -96,7 +97,7 @@ static inline void rcu_read_lock(void) static inline void rcu_read_unlock(void) { - struct rcu_reader_data *p_rcu_reader = &rcu_reader; + struct rcu_reader_data *p_rcu_reader = get_ptr_rcu_reader(); assert(p_rcu_reader->depth != 0); if (--p_rcu_reader->depth > 0) { diff --git a/tests/unit/rcutorture.c b/tests/unit/rcutorture.c index de6f649058..495a4e6f42 100644 --- a/tests/unit/rcutorture.c +++ b/tests/unit/rcutorture.c @@ -122,7 +122,7 @@ static void *rcu_read_perf_test(void *arg) rcu_register_thread(); - *(struct rcu_reader_data **)arg = &rcu_reader; + *(struct rcu_reader_data **)arg = get_ptr_rcu_reader(); qatomic_inc(&nthreadsrunning); while (goflag == GOFLAG_INIT) { g_usleep(1000); @@ -148,7 +148,7 @@ static void *rcu_update_perf_test(void *arg) rcu_register_thread(); - *(struct rcu_reader_data **)arg = &rcu_reader; + *(struct rcu_reader_data **)arg = get_ptr_rcu_reader(); qatomic_inc(&nthreadsrunning); while (goflag == GOFLAG_INIT) { g_usleep(1000); @@ -253,7 +253,7 @@ static void *rcu_read_stress_test(void *arg) rcu_register_thread(); - *(struct rcu_reader_data **)arg = &rcu_reader; + *(struct rcu_reader_data **)arg = get_ptr_rcu_reader(); while (goflag == GOFLAG_INIT) { g_usleep(1000); } @@ -304,7 +304,7 @@ static void *rcu_update_stress_test(void *arg) struct rcu_stress *cp = qatomic_read(&rcu_stress_current); rcu_register_thread(); - *(struct rcu_reader_data **)arg = &rcu_reader; + *(struct rcu_reader_data **)arg = get_ptr_rcu_reader(); while (goflag == GOFLAG_INIT) { g_usleep(1000); @@ -347,7 +347,7 @@ static void *rcu_fake_update_stress_test(void *arg) { rcu_register_thread(); - *(struct rcu_reader_data **)arg = &rcu_reader; + *(struct rcu_reader_data **)arg = get_ptr_rcu_reader(); while (goflag == GOFLAG_INIT) { g_usleep(1000); } diff --git a/tests/unit/test-rcu-list.c b/tests/unit/test-rcu-list.c index 49641e1936..64b81ae058 100644 --- a/tests/unit/test-rcu-list.c +++ b/tests/unit/test-rcu-list.c @@ -171,7 +171,7 @@ static void *rcu_q_reader(void *arg) rcu_register_thread(); - *(struct rcu_reader_data **)arg = &rcu_reader; + *(struct rcu_reader_data **)arg = get_ptr_rcu_reader(); qatomic_inc(&nthreadsrunning); while (qatomic_read(&goflag) == GOFLAG_INIT) { g_usleep(1000); @@ -206,7 +206,7 @@ static void *rcu_q_updater(void *arg) long long n_removed_local = 0; struct list_element *el, *prev_el; - *(struct rcu_reader_data **)arg = &rcu_reader; + *(struct rcu_reader_data **)arg = get_ptr_rcu_reader(); qatomic_inc(&nthreadsrunning); while (qatomic_read(&goflag) == GOFLAG_INIT) { g_usleep(1000); diff --git a/util/rcu.c b/util/rcu.c index c91da9f137..b6d6c71cff 100644 --- a/util/rcu.c +++ b/util/rcu.c @@ -65,7 +65,7 @@ static inline int rcu_gp_ongoing(unsigned long *ctr) /* Written to only by each individual reader. Read by both the reader and the * writers. */ -__thread struct rcu_reader_data rcu_reader; +QEMU_DEFINE_CO_TLS(struct rcu_reader_data, rcu_reader) /* Protected by rcu_registry_lock. */ typedef QLIST_HEAD(, rcu_reader_data) ThreadList; @@ -355,23 +355,23 @@ void drain_call_rcu(void) void rcu_register_thread(void) { - assert(rcu_reader.ctr == 0); + assert(get_ptr_rcu_reader()->ctr == 0); qemu_mutex_lock(&rcu_registry_lock); - QLIST_INSERT_HEAD(®istry, &rcu_reader, node); + QLIST_INSERT_HEAD(®istry, get_ptr_rcu_reader(), node); qemu_mutex_unlock(&rcu_registry_lock); } void rcu_unregister_thread(void) { qemu_mutex_lock(&rcu_registry_lock); - QLIST_REMOVE(&rcu_reader, node); + QLIST_REMOVE(get_ptr_rcu_reader(), node); qemu_mutex_unlock(&rcu_registry_lock); } void rcu_add_force_rcu_notifier(Notifier *n) { qemu_mutex_lock(&rcu_registry_lock); - notifier_list_add(&rcu_reader.force_rcu, n); + notifier_list_add(&get_ptr_rcu_reader()->force_rcu, n); qemu_mutex_unlock(&rcu_registry_lock); }