X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libringbuffer%2Ffrontend_api.h;h=75146e60bef33a23937f71d27e254b486ae1f7c9;hb=9f3fdbc68877e1f12b6cedb15ef76d9af9b48bac;hp=ebe5db493f71f220d1d05f9117a9f53bbcf036b6;hpb=4fbf9cd1ede72e98638a5f81ecdce11416b4afea;p=lttng-ust.git diff --git a/libringbuffer/frontend_api.h b/libringbuffer/frontend_api.h index ebe5db49..75146e60 100644 --- a/libringbuffer/frontend_api.h +++ b/libringbuffer/frontend_api.h @@ -18,14 +18,17 @@ */ #include "frontend.h" +#include "ust/core.h" +#include +#include /** * lib_ring_buffer_get_cpu - Precedes ring buffer reserve/commit. * - * Disables preemption (acts as a RCU read-side critical section) and keeps a - * ring buffer nesting count as supplementary safety net to ensure tracer client - * code will never trigger an endless recursion. Returns the processor ID on - * success, -EPERM on failure (nesting count too high). + * Grabs RCU read-side lock and keeps a ring buffer nesting count as + * supplementary safety net to ensure tracer client code will never + * trigger an endless recursion. Returns the processor ID on success, + * -EPERM on failure (nesting count too high). * * asm volatile and "memory" clobber prevent the compiler from moving * instructions out of the ring buffer nesting count. This is required to ensure @@ -38,15 +41,15 @@ int lib_ring_buffer_get_cpu(const struct lib_ring_buffer_config *config) { int cpu, nesting; - rcu_read_lock_sched_notrace(); - cpu = smp_processor_id(); + rcu_read_lock(); + cpu = ust_get_cpu(); nesting = ++lib_ring_buffer_nesting; /* TLS */ - barrier(); + cmm_barrier(); if (unlikely(nesting > 4)) { WARN_ON_ONCE(1); lib_ring_buffer_nesting--; /* TLS */ - rcu_read_unlock_sched_notrace(); + rcu_read_unlock(); return -EPERM; } else return cpu; @@ -58,9 +61,9 @@ int lib_ring_buffer_get_cpu(const struct lib_ring_buffer_config *config) static inline void lib_ring_buffer_put_cpu(const struct lib_ring_buffer_config *config) { - barrier(); + cmm_barrier(); lib_ring_buffer_nesting--; /* TLS */ - rcu_read_unlock_sched_notrace(); + rcu_read_unlock(); } /* @@ -89,7 +92,7 @@ int lib_ring_buffer_try_reserve(const struct lib_ring_buffer_config *config, * commit counter to increment it and commit seq value to compare it to * the commit counter. */ - prefetch(&buf->commit_hot[subbuf_index(*o_begin, chan)]); + //prefetch(&buf->commit_hot[subbuf_index(*o_begin, chan)]); if (last_tsc_overflow(config, buf, ctx->tsc)) ctx->rflags |= RING_BUFFER_RFLAG_FULL_TSC; @@ -147,14 +150,14 @@ int lib_ring_buffer_reserve(const struct lib_ring_buffer_config *config, unsigned long o_begin, o_end, o_old; size_t before_hdr_pad = 0; - if (atomic_read(&chan->record_disabled)) + if (uatomic_read(&chan->record_disabled)) return -EAGAIN; if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) - buf = per_cpu_ptr(chan->backend.buf, ctx->cpu); + buf = &shmp(chan->backend.buf)[ctx->cpu]; else - buf = chan->backend.buf; - if (atomic_read(&buf->record_disabled)) + buf = shmp(chan->backend.buf); + if (uatomic_read(&buf->record_disabled)) return -EAGAIN; ctx->buf = buf; @@ -245,17 +248,9 @@ void lib_ring_buffer_commit(const struct lib_ring_buffer_config *config, * Order all writes to buffer before the commit count update that will * determine that the subbuffer is full. */ - if (config->ipi == RING_BUFFER_IPI_BARRIER) { - /* - * Must write slot data before incrementing commit count. This - * compiler barrier is upgraded into a smp_mb() by the IPI sent - * by get_subbuf(). - */ - barrier(); - } else - smp_wmb(); + cmm_smp_wmb(); - v_add(config, ctx->slot_size, &buf->commit_hot[endidx].cc); + v_add(config, ctx->slot_size, &shmp(buf->commit_hot)[endidx].cc); /* * commit count read can race with concurrent OOO commit count updates. @@ -275,7 +270,7 @@ void lib_ring_buffer_commit(const struct lib_ring_buffer_config *config, * count reaches back the reserve offset for a specific sub-buffer, * which is completely independent of the order. */ - commit_count = v_read(config, &buf->commit_hot[endidx].cc); + commit_count = v_read(config, &shmp(buf->commit_hot)[endidx].cc); lib_ring_buffer_check_deliver(config, buf, chan, offset_end - 1, commit_count, endidx); @@ -330,28 +325,28 @@ static inline void channel_record_disable(const struct lib_ring_buffer_config *config, struct channel *chan) { - atomic_inc(&chan->record_disabled); + uatomic_inc(&chan->record_disabled); } static inline void channel_record_enable(const struct lib_ring_buffer_config *config, struct channel *chan) { - atomic_dec(&chan->record_disabled); + uatomic_dec(&chan->record_disabled); } static inline void lib_ring_buffer_record_disable(const struct lib_ring_buffer_config *config, struct lib_ring_buffer *buf) { - atomic_inc(&buf->record_disabled); + uatomic_inc(&buf->record_disabled); } static inline void lib_ring_buffer_record_enable(const struct lib_ring_buffer_config *config, struct lib_ring_buffer *buf) { - atomic_dec(&buf->record_disabled); + uatomic_dec(&buf->record_disabled); } #endif /* _LINUX_RING_BUFFER_FRONTEND_API_H */