X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libust%2Fbuffers.c;h=8ecebb9355060bb752d7f66f9f0f4f0895ac747f;hb=283f11580b1ef306fc9592bde3c352d9216521be;hp=9651beb916db5d78b8acbae83ded896513963c3f;hpb=909bc43f70be2b1d3efcefe33121ee1e99d9895b;p=ust.git diff --git a/libust/buffers.c b/libust/buffers.c index 9651beb..8ecebb9 100644 --- a/libust/buffers.c +++ b/libust/buffers.c @@ -3,7 +3,7 @@ * LTTng userspace tracer buffering system * * Copyright (C) 2009 - Pierre-Marc Fournier (pierre-marc dot fournier at polymtl dot ca) - * Copyright (C) 2008 - Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca) + * Copyright (C) 2008-2011 - Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -20,19 +20,27 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +/* + * Note: this code does not support the ref/noref flag and reader-owned + * subbuffer scheme. Therefore, flight recorder mode uses a mechanism + * where the reader can read corrupted data (and detect this), thus + * returning -EIO. + */ + #include #include #include #include #include -#include -#include #include + +#include + #include "buffers.h" #include "channels.h" #include "tracer.h" #include "tracercore.h" -#include "usterr.h" +#include "usterr_signal_safe.h" struct ltt_reserve_switch_offsets { long begin, end, old; @@ -42,65 +50,123 @@ struct ltt_reserve_switch_offsets { static DEFINE_MUTEX(ust_buffers_channels_mutex); -static LIST_HEAD(ust_buffers_channels); +static CDS_LIST_HEAD(ust_buffers_channels); + +static void ltt_force_switch(struct ust_buffer *buf, + enum force_switch_mode mode); static int get_n_cpus(void) { int result; static int n_cpus = 0; - if(n_cpus) { - return n_cpus; - } + if(!n_cpus) { + /* On Linux, when some processors are offline + * _SC_NPROCESSORS_CONF counts the offline + * processors, whereas _SC_NPROCESSORS_ONLN + * does not. If we used _SC_NPROCESSORS_ONLN, + * getcpu() could return a value greater than + * this sysconf, in which case the arrays + * indexed by processor would overflow. + */ + result = sysconf(_SC_NPROCESSORS_CONF); + if(result == -1) { + return -1; + } - /* On Linux, when some processors are offline - * _SC_NPROCESSORS_CONF counts the offline - * processors, whereas _SC_NPROCESSORS_ONLN - * does not. If we used _SC_NPROCESSORS_ONLN, - * getcpu() could return a value greater than - * this sysconf, in which case the arrays - * indexed by processor would overflow. - */ - result = sysconf(_SC_NPROCESSORS_CONF); - if(result == -1) { - return -1; + n_cpus = result; } - n_cpus = result; - - return result; + return n_cpus; } -/* _ust_buffers_write() +/** + * _ust_buffers_strncpy_fixup - Fix an incomplete string in a ltt_relay buffer. + * @buf : buffer + * @offset : offset within the buffer + * @len : length to write + * @copied: string actually copied + * @terminated: does string end with \0 * - * @buf: destination buffer - * @offset: offset in destination - * @src: source buffer - * @len: length of source - * @cpy: already copied + * Fills string with "X" if incomplete. */ - -void _ust_buffers_write(struct ust_buffer *buf, size_t offset, - const void *src, size_t len, ssize_t cpy) +void _ust_buffers_strncpy_fixup(struct ust_buffer *buf, size_t offset, + size_t len, size_t copied, int terminated) { - do { - len -= cpy; - src += cpy; - offset += cpy; + size_t buf_offset, cpy; + + if (copied == len) { + /* + * Deal with non-terminated string. + */ + assert(!terminated); + offset += copied - 1; + buf_offset = BUFFER_OFFSET(offset, buf->chan); + /* + * Underlying layer should never ask for writes across + * subbuffers. + */ + assert(buf_offset + < buf->chan->subbuf_size*buf->chan->subbuf_cnt); + ust_buffers_do_memset(buf->buf_data + buf_offset, '\0', 1); + return; + } + + /* + * Deal with incomplete string. + * Overwrite string's \0 with X too. + */ + cpy = copied - 1; + assert(terminated); + len -= cpy; + offset += cpy; + buf_offset = BUFFER_OFFSET(offset, buf->chan); + + /* + * Underlying layer should never ask for writes across subbuffers. + */ + assert(buf_offset + < buf->chan->subbuf_size*buf->chan->subbuf_cnt); - WARN_ON(offset >= buf->buf_size); + ust_buffers_do_memset(buf->buf_data + buf_offset, + 'X', len); - cpy = min_t(size_t, len, buf->buf_size - offset); - ust_buffers_do_copy(buf->buf_data + offset, src, cpy); - } while (unlikely(len != cpy)); + /* + * Overwrite last 'X' with '\0'. + */ + offset += len - 1; + buf_offset = BUFFER_OFFSET(offset, buf->chan); + /* + * Underlying layer should never ask for writes across subbuffers. + */ + assert(buf_offset + < buf->chan->subbuf_size*buf->chan->subbuf_cnt); + ust_buffers_do_memset(buf->buf_data + buf_offset, '\0', 1); } -static int ust_buffers_init_buffer(struct ust_trace *trace, - struct ust_channel *ltt_chan, - struct ust_buffer *buf, - unsigned int n_subbufs); +static void ltt_buffer_begin(struct ust_buffer *buf, + u64 tsc, unsigned int subbuf_idx) +{ + struct ust_channel *channel = buf->chan; + struct ltt_subbuffer_header *header = + (struct ltt_subbuffer_header *) + ust_buffers_offset_address(buf, + subbuf_idx * buf->chan->subbuf_size); -static int ust_buffers_alloc_buf(struct ust_buffer *buf, size_t *size) + header->cycle_count_begin = tsc; + header->data_size = 0xFFFFFFFF; /* for recognizing crashed buffers */ + header->sb_size = 0xFFFFFFFF; /* for recognizing crashed buffers */ + /* + * No memory barrier needed to order data_data/sb_size vs commit count + * update, because commit count update contains a compiler barrier that + * ensures the order of the writes are OK from a program POV. It only + * matters for crash dump recovery which is not executed concurrently, + * so memory write order does not matter. + */ + ltt_write_trace_header(channel->trace, header); +} + +static int map_buf_data(struct ust_buffer *buf, size_t *size) { void *ptr; int result; @@ -108,18 +174,16 @@ static int ust_buffers_alloc_buf(struct ust_buffer *buf, size_t *size) *size = PAGE_ALIGN(*size); result = buf->shmid = shmget(getpid(), *size, IPC_CREAT | IPC_EXCL | 0700); - if(result == -1 && errno == EINVAL) { + if (result < 0 && errno == EINVAL) { ERR("shmget() returned EINVAL; maybe /proc/sys/kernel/shmmax should be increased."); return -1; - } - else if(result == -1) { + } else if (result < 0) { PERROR("shmget"); return -1; } - /* FIXME: should have matching call to shmdt */ ptr = shmat(buf->shmid, NULL, 0); - if(ptr == (void *) -1) { + if (ptr == (void *) -1) { perror("shmat"); goto destroy_shmem; } @@ -138,7 +202,7 @@ static int ust_buffers_alloc_buf(struct ust_buffer *buf, size_t *size) return 0; - destroy_shmem: +destroy_shmem: result = shmctl(buf->shmid, IPC_RMID, NULL); if(result == -1) { perror("shmctl"); @@ -147,78 +211,88 @@ static int ust_buffers_alloc_buf(struct ust_buffer *buf, size_t *size) return -1; } -int ust_buffers_create_buf(struct ust_channel *channel, int cpu) +static int open_buf(struct ust_channel *chan, int cpu) { - int result; - struct ust_buffer *buf = channel->buf[cpu]; + int result, fds[2]; + unsigned int j; + struct ust_trace *trace = chan->trace; + struct ust_buffer *buf = chan->buf[cpu]; + unsigned int n_subbufs = chan->subbuf_cnt; - buf->cpu = cpu; - result = ust_buffers_alloc_buf(buf, &channel->alloc_size); - if(result) + + result = map_buf_data(buf, &chan->alloc_size); + if (result < 0) return -1; - buf->chan = channel; - kref_get(&channel->kref); - return 0; -} + buf->commit_count = + zmalloc(sizeof(*buf->commit_count) * n_subbufs); + if (!buf->commit_count) + goto unmap_buf; -static void ust_buffers_destroy_channel(struct kref *kref) -{ - struct ust_channel *chan = container_of(kref, struct ust_channel, kref); - free(chan); -} + result = pipe(fds); + if (result < 0) { + PERROR("pipe"); + goto free_commit_count; + } + buf->data_ready_fd_read = fds[0]; + buf->data_ready_fd_write = fds[1]; -static void ust_buffers_destroy_buf(struct ust_buffer *buf) -{ - struct ust_channel *chan = buf->chan; - int result; + buf->cpu = cpu; + buf->chan = chan; - result = munmap(buf->buf_data, buf->buf_size); - if(result == -1) { - PERROR("munmap"); + uatomic_set(&buf->offset, ltt_subbuffer_header_size()); + uatomic_set(&buf->consumed, 0); + uatomic_set(&buf->active_readers, 0); + for (j = 0; j < n_subbufs; j++) { + uatomic_set(&buf->commit_count[j].cc, 0); + uatomic_set(&buf->commit_count[j].cc_sb, 0); } -//ust// chan->buf[buf->cpu] = NULL; - free(buf); - kref_put(&chan->kref, ust_buffers_destroy_channel); -} + ltt_buffer_begin(buf, trace->start_tsc, 0); -/* called from kref_put */ -static void ust_buffers_remove_buf(struct kref *kref) -{ - struct ust_buffer *buf = container_of(kref, struct ust_buffer, kref); - ust_buffers_destroy_buf(buf); -} + uatomic_add(&buf->commit_count[0].cc, ltt_subbuffer_header_size()); -int ust_buffers_open_buf(struct ust_channel *chan, int cpu) -{ - int result; + uatomic_set(&buf->events_lost, 0); + uatomic_set(&buf->corrupted_subbuffers, 0); - result = ust_buffers_create_buf(chan, cpu); - if (result == -1) - return -1; + memset(buf->commit_seq, 0, sizeof(buf->commit_seq[0]) * n_subbufs); - kref_init(&chan->buf[cpu]->kref); + return 0; - result = ust_buffers_init_buffer(chan->trace, chan, chan->buf[cpu], chan->subbuf_cnt); - if(result == -1) - return -1; +free_commit_count: + free(buf->commit_count); - return 0; +unmap_buf: + if (shmdt(buf->buf_data) < 0) { + PERROR("shmdt failed"); + } - /* FIXME: decrementally destroy on error? */ + return -1; } -/** - * ust_buffers_close_buf - close a channel buffer - * @buf: buffer - */ -static void ust_buffers_close_buf(struct ust_buffer *buf) +static void close_buf(struct ust_buffer *buf) { - kref_put(&buf->kref, ust_buffers_remove_buf); + int result; + + result = shmdt(buf->buf_data); + if (result < 0) { + PERROR("shmdt"); + } + + result = close(buf->data_ready_fd_read); + if (result < 0) { + PERROR("close"); + } + + result = close(buf->data_ready_fd_write); + if (result < 0 && errno != EBADF) { + PERROR("close"); + } } -int ust_buffers_channel_open(struct ust_channel *chan, size_t subbuf_size, size_t subbuf_cnt) + +static int open_channel(struct ust_channel *chan, size_t subbuf_size, + size_t subbuf_cnt) { int i; int result; @@ -241,77 +315,47 @@ int ust_buffers_channel_open(struct ust_channel *chan, size_t subbuf_size, size_ chan->subbuf_size_order = get_count_order(subbuf_size); chan->alloc_size = subbuf_size * subbuf_cnt; - kref_init(&chan->kref); - - mutex_lock(&ust_buffers_channels_mutex); - for(i=0; in_cpus; i++) { - result = ust_buffers_open_buf(chan, i); + pthread_mutex_lock(&ust_buffers_channels_mutex); + for (i=0; i < chan->n_cpus; i++) { + result = open_buf(chan, i); if (result == -1) goto error; } - list_add(&chan->list, &ust_buffers_channels); - mutex_unlock(&ust_buffers_channels_mutex); + cds_list_add(&chan->list, &ust_buffers_channels); + pthread_mutex_unlock(&ust_buffers_channels_mutex); return 0; - /* Jump directly inside the loop to close the buffers that were already - * opened. */ - for(; i>=0; i--) { - ust_buffers_close_buf(chan->buf[i]); + /* Error handling */ error: - do {} while(0); - } + for(i--; i >= 0; i--) + close_buf(chan->buf[i]); - kref_put(&chan->kref, ust_buffers_destroy_channel); - mutex_unlock(&ust_buffers_channels_mutex); + pthread_mutex_unlock(&ust_buffers_channels_mutex); return -1; } -void ust_buffers_channel_close(struct ust_channel *chan) +static void close_channel(struct ust_channel *chan) { int i; if(!chan) return; - mutex_lock(&ust_buffers_channels_mutex); - for(i=0; in_cpus; i++) { - /* FIXME: if we make it here, then all buffers were necessarily allocated. Moreover, we don't - * initialize to NULL so we cannot use this check. Should we? */ -//ust// if (chan->buf[i]) - ust_buffers_close_buf(chan->buf[i]); + pthread_mutex_lock(&ust_buffers_channels_mutex); + /* + * checking for chan->buf[i] being NULL or not is useless in + * practice because we allocate buffers for all possible cpus. + * However, should we decide to change this and only allocate + * for online cpus, this check becomes useful. + */ + for (i=0; in_cpus; i++) { + if (chan->buf[i]) + close_buf(chan->buf[i]); } - list_del(&chan->list); - kref_put(&chan->kref, ust_buffers_destroy_channel); - mutex_unlock(&ust_buffers_channels_mutex); -} + cds_list_del(&chan->list); -/* - * ------- - */ - -static void ust_buffers_destroy_buffer(struct ust_channel *ltt_chan, int cpu); - -static void ltt_force_switch(struct ust_buffer *buf, - enum force_switch_mode mode); - -/* - * Trace callbacks - */ -static void ltt_buffer_begin(struct ust_buffer *buf, - u64 tsc, unsigned int subbuf_idx) -{ - struct ust_channel *channel = buf->chan; - struct ltt_subbuffer_header *header = - (struct ltt_subbuffer_header *) - ust_buffers_offset_address(buf, - subbuf_idx * buf->chan->subbuf_size); - - header->cycle_count_begin = tsc; - header->data_size = 0xFFFFFFFF; /* for recognizing crashed buffers */ - header->sb_size = 0xFFFFFFFF; /* for recognizing crashed buffers */ - /* FIXME: add memory barrier? */ - ltt_write_trace_header(channel->trace, header); + pthread_mutex_unlock(&ust_buffers_channels_mutex); } /* @@ -327,7 +371,6 @@ static notrace void ltt_buffer_end(struct ust_buffer *buf, subbuf_idx * buf->chan->subbuf_size); u32 data_size = SUBBUF_OFFSET(offset - 1, buf->chan) + 1; - header->data_size = data_size; header->sb_size = PAGE_ALIGN(data_size); header->cycle_count_end = tsc; header->events_lost = uatomic_read(&buf->events_lost); @@ -335,6 +378,13 @@ static notrace void ltt_buffer_end(struct ust_buffer *buf, if(unlikely(header->events_lost > 0)) { DBG("Some events (%d) were lost in %s_%d", header->events_lost, buf->chan->channel_name, buf->cpu); } + /* + * Makes sure data_size write happens after write of the rest of the + * buffer end data, because data_size is used to identify a completely + * written subbuffer in a crash dump. + */ + cmm_barrier(); + header->data_size = data_size; } /* @@ -347,7 +397,7 @@ static notrace void ltt_buf_unfull(struct ust_buffer *buf, } /* - * Promote compiler barrier to a smp_mb(). + * Promote compiler cmm_barrier to a smp_mb(). * For the specific LTTng case, this IPI call should be removed if the * architecture does not reorder writes. This should eventually be provided by * a separate architecture-specific infrastructure. @@ -371,51 +421,13 @@ int ust_buffers_get_subbuf(struct ust_buffer *buf, long *consumed) * data and the write offset. Correct consumed offset ordering * wrt commit count is insured by the use of cmpxchg to update * the consumed offset. - * smp_call_function_single can fail if the remote CPU is offline, - * this is OK because then there is no wmb to execute there. - * If our thread is executing on the same CPU as the on the buffers - * belongs to, we don't have to synchronize it at all. If we are - * migrated, the scheduler will take care of the memory barriers. - * Normally, smp_call_function_single() should ensure program order when - * executing the remote function, which implies that it surrounds the - * function execution with : - * smp_mb() - * send IPI - * csd_lock_wait - * recv IPI - * smp_mb() - * exec. function - * smp_mb() - * csd unlock - * smp_mb() - * - * However, smp_call_function_single() does not seem to clearly execute - * such barriers. It depends on spinlock semantic to provide the barrier - * before executing the IPI and, when busy-looping, csd_lock_wait only - * executes smp_mb() when it has to wait for the other CPU. - * - * I don't trust this code. Therefore, let's add the smp_mb() sequence - * required ourself, even if duplicated. It has no performance impact - * anyway. - * - * smp_mb() is needed because smp_rmb() and smp_wmb() only order read vs - * read and write vs write. They do not ensure core synchronization. We - * really have to ensure total order between the 3 barriers running on - * the 2 CPUs. */ -//ust// #ifdef LTT_NO_IPI_BARRIER + /* * Local rmb to match the remote wmb to read the commit count before the * buffer data and the write offset. */ - smp_rmb(); -//ust// #else -//ust// if (raw_smp_processor_id() != buf->cpu) { -//ust// smp_mb(); /* Total order with IPI handler smp_mb() */ -//ust// smp_call_function_single(buf->cpu, remote_mb, NULL, 1); -//ust// smp_mb(); /* Total order with IPI handler smp_mb() */ -//ust// } -//ust// #endif + cmm_smp_rmb(); write_offset = uatomic_read(&buf->offset); /* @@ -438,12 +450,6 @@ int ust_buffers_get_subbuf(struct ust_buffer *buf, long *consumed) == 0) { return -EAGAIN; } - - /* FIXME: is this ok to disable the reading feature? */ -//ust// retval = update_read_sb_index(buf, consumed_idx); -//ust// if (retval) -//ust// return retval; - *consumed = consumed_old; return 0; @@ -458,14 +464,12 @@ int ust_buffers_put_subbuf(struct ust_buffer *buf, unsigned long uconsumed_old) consumed_old = consumed_old | uconsumed_old; consumed_new = SUBBUF_ALIGN(consumed_old, buf->chan); -//ust// spin_lock(<t_buf->full_lock); if (uatomic_cmpxchg(&buf->consumed, consumed_old, consumed_new) != consumed_old) { /* We have been pushed by the writer : the last * buffer read _is_ corrupted! It can also * happen if this is a buffer we never got. */ -//ust// spin_unlock(<t_buf->full_lock); return -EIO; } else { /* tell the client that buffer is now unfull */ @@ -474,292 +478,11 @@ int ust_buffers_put_subbuf(struct ust_buffer *buf, unsigned long uconsumed_old) index = SUBBUF_INDEX(consumed_old, buf->chan); data = BUFFER_OFFSET(consumed_old, buf->chan); ltt_buf_unfull(buf, index, data); -//ust// spin_unlock(<t_buf->full_lock); } return 0; } -//ust// static void switch_buffer(unsigned long data) -//ust// { -//ust// struct ltt_channel_buf_struct *ltt_buf = -//ust// (struct ltt_channel_buf_struct *)data; -//ust// struct rchan_buf *buf = ltt_buf->rbuf; -//ust// -//ust// if (buf) -//ust// ltt_force_switch(buf, FORCE_ACTIVE); -//ust// -//ust// ltt_buf->switch_timer.expires += ltt_buf->switch_timer_interval; -//ust// add_timer_on(<t_buf->switch_timer, smp_processor_id()); -//ust// } -//ust// -//ust// static void start_switch_timer(struct ltt_channel_struct *ltt_channel) -//ust// { -//ust// struct rchan *rchan = ltt_channel->trans_channel_data; -//ust// int cpu; -//ust// -//ust// if (!ltt_channel->switch_timer_interval) -//ust// return; -//ust// -//ust// // TODO : hotplug -//ust// for_each_online_cpu(cpu) { -//ust// struct ltt_channel_buf_struct *ltt_buf; -//ust// struct rchan_buf *buf; -//ust// -//ust// buf = rchan->buf[cpu]; -//ust// ltt_buf = buf->chan_private; -//ust// buf->random_access = 1; -//ust// ltt_buf->switch_timer_interval = -//ust// ltt_channel->switch_timer_interval; -//ust// init_timer(<t_buf->switch_timer); -//ust// ltt_buf->switch_timer.function = switch_buffer; -//ust// ltt_buf->switch_timer.expires = jiffies + -//ust// ltt_buf->switch_timer_interval; -//ust// ltt_buf->switch_timer.data = (unsigned long)ltt_buf; -//ust// add_timer_on(<t_buf->switch_timer, cpu); -//ust// } -//ust// } -//ust// -//ust// /* -//ust// * Cannot use del_timer_sync with add_timer_on, so use an IPI to locally -//ust// * delete the timer. -//ust// */ -//ust// static void stop_switch_timer_ipi(void *info) -//ust// { -//ust// struct ltt_channel_buf_struct *ltt_buf = -//ust// (struct ltt_channel_buf_struct *)info; -//ust// -//ust// del_timer(<t_buf->switch_timer); -//ust// } -//ust// -//ust// static void stop_switch_timer(struct ltt_channel_struct *ltt_channel) -//ust// { -//ust// struct rchan *rchan = ltt_channel->trans_channel_data; -//ust// int cpu; -//ust// -//ust// if (!ltt_channel->switch_timer_interval) -//ust// return; -//ust// -//ust// // TODO : hotplug -//ust// for_each_online_cpu(cpu) { -//ust// struct ltt_channel_buf_struct *ltt_buf; -//ust// struct rchan_buf *buf; -//ust// -//ust// buf = rchan->buf[cpu]; -//ust// ltt_buf = buf->chan_private; -//ust// smp_call_function(stop_switch_timer_ipi, ltt_buf, 1); -//ust// buf->random_access = 0; -//ust// } -//ust// } - -//ust// static void ust_buffers_print_written(struct ust_channel *chan, -//ust// long cons_off, unsigned int cpu) -//ust// { -//ust// struct ust_buffer *buf = chan->buf[cpu]; -//ust// long cons_idx, events_count; -//ust// -//ust// cons_idx = SUBBUF_INDEX(cons_off, chan); -//ust// events_count = uatomic_read(&buf->commit_count[cons_idx].events); -//ust// -//ust// if (events_count) -//ust// printk(KERN_INFO -//ust// "channel %s: %lu events written (cpu %u, index %lu)\n", -//ust// chan->channel_name, events_count, cpu, cons_idx); -//ust// } - -static void ltt_relay_print_subbuffer_errors( - struct ust_channel *channel, - long cons_off, int cpu) -{ - struct ust_buffer *ltt_buf = channel->buf[cpu]; - long cons_idx, commit_count, commit_count_sb, write_offset; - - cons_idx = SUBBUF_INDEX(cons_off, channel); - commit_count = uatomic_read(<t_buf->commit_count[cons_idx].cc); - commit_count_sb = uatomic_read(<t_buf->commit_count[cons_idx].cc_sb); - - /* - * No need to order commit_count and write_offset reads because we - * execute after trace is stopped when there are no readers left. - */ - write_offset = uatomic_read(<t_buf->offset); - WARN( "LTT : unread channel %s offset is %ld " - "and cons_off : %ld (cpu %d)\n", - channel->channel_name, write_offset, cons_off, cpu); - /* Check each sub-buffer for non filled commit count */ - if (((commit_count - channel->subbuf_size) & channel->commit_count_mask) - - (BUFFER_TRUNC(cons_off, channel) >> channel->n_subbufs_order) != 0) { - ERR("LTT : %s : subbuffer %lu has non filled " - "commit count [cc, cc_sb] [%lu,%lu].\n", - channel->channel_name, cons_idx, commit_count, commit_count_sb); - } - ERR("LTT : %s : commit count : %lu, subbuf size %zd\n", - channel->channel_name, commit_count, - channel->subbuf_size); -} - -static void ltt_relay_print_errors(struct ust_trace *trace, - struct ust_channel *channel, int cpu) -{ - struct ust_buffer *ltt_buf = channel->buf[cpu]; - long cons_off; - - /* - * Can be called in the error path of allocation when - * trans_channel_data is not yet set. - */ - if (!channel) - return; - -//ust// for (cons_off = 0; cons_off < rchan->alloc_size; -//ust// cons_off = SUBBUF_ALIGN(cons_off, rchan)) -//ust// ust_buffers_print_written(ltt_chan, cons_off, cpu); - for (cons_off = uatomic_read(<t_buf->consumed); - (SUBBUF_TRUNC(uatomic_read(<t_buf->offset), - channel) - - cons_off) > 0; - cons_off = SUBBUF_ALIGN(cons_off, channel)) - ltt_relay_print_subbuffer_errors(channel, cons_off, cpu); -} - -static void ltt_relay_print_buffer_errors(struct ust_channel *channel, int cpu) -{ - struct ust_trace *trace = channel->trace; - struct ust_buffer *ltt_buf = channel->buf[cpu]; - - if (uatomic_read(<t_buf->events_lost)) - ERR("channel %s: %ld events lost (cpu %d)", - channel->channel_name, - uatomic_read(<t_buf->events_lost), cpu); - if (uatomic_read(<t_buf->corrupted_subbuffers)) - ERR("channel %s : %ld corrupted subbuffers (cpu %d)", - channel->channel_name, - uatomic_read(<t_buf->corrupted_subbuffers), cpu); - - ltt_relay_print_errors(trace, channel, cpu); -} - -static void ltt_relay_release_channel(struct kref *kref) -{ - struct ust_channel *ltt_chan = container_of(kref, - struct ust_channel, kref); - free(ltt_chan->buf); -} - -/* - * Create ltt buffer. - */ -//ust// static int ltt_relay_create_buffer(struct ust_trace *trace, -//ust// struct ltt_channel_struct *ltt_chan, struct rchan_buf *buf, -//ust// unsigned int cpu, unsigned int n_subbufs) -//ust// { -//ust// struct ltt_channel_buf_struct *ltt_buf = -//ust// percpu_ptr(ltt_chan->buf, cpu); -//ust// unsigned int j; -//ust// -//ust// ltt_buf->commit_count = -//ust// kzalloc_node(sizeof(ltt_buf->commit_count) * n_subbufs, -//ust// GFP_KERNEL, cpu_to_node(cpu)); -//ust// if (!ltt_buf->commit_count) -//ust// return -ENOMEM; -//ust// kref_get(&trace->kref); -//ust// kref_get(&trace->ltt_transport_kref); -//ust// kref_get(<t_chan->kref); -//ust// uatomic_set(<t_buf->offset, ltt_subbuffer_header_size()); -//ust// uatomic_set(<t_buf->consumed, 0); -//ust// uatomic_set(<t_buf->active_readers, 0); -//ust// for (j = 0; j < n_subbufs; j++) -//ust// uatomic_set(<t_buf->commit_count[j], 0); -//ust// init_waitqueue_head(<t_buf->write_wait); -//ust// uatomic_set(<t_buf->wakeup_readers, 0); -//ust// spin_lock_init(<t_buf->full_lock); -//ust// -//ust// ltt_buffer_begin_callback(buf, trace->start_tsc, 0); -//ust// /* atomic_add made on local variable on data that belongs to -//ust// * various CPUs : ok because tracing not started (for this cpu). */ -//ust// uatomic_add(<t_buf->commit_count[0], ltt_subbuffer_header_size()); -//ust// -//ust// uatomic_set(<t_buf->events_lost, 0); -//ust// uatomic_set(<t_buf->corrupted_subbuffers, 0); -//ust// -//ust// return 0; -//ust// } - -static int ust_buffers_init_buffer(struct ust_trace *trace, - struct ust_channel *ltt_chan, struct ust_buffer *buf, - unsigned int n_subbufs) -{ - unsigned int j; - int fds[2]; - int result; - - buf->commit_count = - zmalloc(sizeof(*buf->commit_count) * n_subbufs); - if (!buf->commit_count) - return -ENOMEM; - kref_get(&trace->kref); - kref_get(&trace->ltt_transport_kref); - kref_get(<t_chan->kref); - uatomic_set(&buf->offset, ltt_subbuffer_header_size()); - uatomic_set(&buf->consumed, 0); - uatomic_set(&buf->active_readers, 0); - for (j = 0; j < n_subbufs; j++) { - uatomic_set(&buf->commit_count[j].cc, 0); - uatomic_set(&buf->commit_count[j].cc_sb, 0); - } -//ust// init_waitqueue_head(&buf->write_wait); -//ust// uatomic_set(&buf->wakeup_readers, 0); -//ust// spin_lock_init(&buf->full_lock); - - ltt_buffer_begin(buf, trace->start_tsc, 0); - - uatomic_add(&buf->commit_count[0].cc, ltt_subbuffer_header_size()); - - uatomic_set(&buf->events_lost, 0); - uatomic_set(&buf->corrupted_subbuffers, 0); - - result = pipe(fds); - if(result == -1) { - PERROR("pipe"); - return -1; - } - buf->data_ready_fd_read = fds[0]; - buf->data_ready_fd_write = fds[1]; - - /* FIXME: do we actually need this? */ - result = fcntl(fds[0], F_SETFL, O_NONBLOCK); - if(result == -1) { - PERROR("fcntl"); - } - -//ust// buf->commit_seq = malloc(sizeof(buf->commit_seq) * n_subbufs); -//ust// if(!ltt_buf->commit_seq) { -//ust// return -1; -//ust// } - memset(buf->commit_seq, 0, sizeof(buf->commit_seq[0]) * n_subbufs); - - /* FIXME: decrementally destroy on error */ - - return 0; -} - -/* FIXME: use this function */ -static void ust_buffers_destroy_buffer(struct ust_channel *ltt_chan, int cpu) -{ - struct ust_trace *trace = ltt_chan->trace; - struct ust_buffer *ltt_buf = ltt_chan->buf[cpu]; - - kref_put(<t_chan->trace->ltt_transport_kref, - ltt_release_transport); - ltt_relay_print_buffer_errors(ltt_chan, cpu); -//ust// free(ltt_buf->commit_seq); - free(ltt_buf->commit_count); - ltt_buf->commit_count = NULL; - kref_put(<t_chan->kref, ltt_relay_release_channel); - kref_put(&trace->kref, ltt_release_trace); -//ust// wake_up_interruptible(&trace->kref_wq); -} - -static int ust_buffers_alloc_channel_buf_structs(struct ust_channel *chan) +static int map_buf_structs(struct ust_channel *chan) { void *ptr; int result; @@ -776,7 +499,6 @@ static int ust_buffers_alloc_channel_buf_structs(struct ust_channel *chan) goto destroy_previous; } - /* FIXME: should have matching call to shmdt */ ptr = shmat(chan->buf_struct_shmids[i], NULL, 0); if(ptr == (void *) -1) { perror("shmat"); @@ -814,507 +536,111 @@ static int ust_buffers_alloc_channel_buf_structs(struct ust_channel *chan) return -1; } +static int unmap_buf_structs(struct ust_channel *chan) +{ + int i; + + for (i=0; i < chan->n_cpus; i++) { + if (shmdt(chan->buf[i]) < 0) { + PERROR("shmdt"); + } + } + return 0; +} + /* * Create channel. */ -static int ust_buffers_create_channel(const char *trace_name, struct ust_trace *trace, - const char *channel_name, struct ust_channel *ltt_chan, +static int create_channel(const char *trace_name, struct ust_trace *trace, + const char *channel_name, struct ust_channel *chan, unsigned int subbuf_size, unsigned int n_subbufs, int overwrite) { - int result; + int i, result; - kref_init(<t_chan->kref); + chan->trace = trace; + chan->overwrite = overwrite; + chan->n_subbufs_order = get_count_order(n_subbufs); + chan->commit_count_mask = (~0UL >> chan->n_subbufs_order); + chan->n_cpus = get_n_cpus(); - ltt_chan->trace = trace; - ltt_chan->overwrite = overwrite; - ltt_chan->n_subbufs_order = get_count_order(n_subbufs); - ltt_chan->commit_count_mask = (~0UL >> ltt_chan->n_subbufs_order); - ltt_chan->n_cpus = get_n_cpus(); -//ust// ltt_chan->buf = percpu_alloc_mask(sizeof(struct ltt_channel_buf_struct), GFP_KERNEL, cpu_possible_map); - ltt_chan->buf = (void *) malloc(ltt_chan->n_cpus * sizeof(void *)); - if(ltt_chan->buf == NULL) { + /* These mappings should ideall be per-cpu, if somebody can do that + * from userspace, that would be cool! + */ + chan->buf = (void *) zmalloc(chan->n_cpus * sizeof(void *)); + if(chan->buf == NULL) { goto error; } - ltt_chan->buf_struct_shmids = (int *) malloc(ltt_chan->n_cpus * sizeof(int)); - if(ltt_chan->buf_struct_shmids == NULL) + chan->buf_struct_shmids = (int *) zmalloc(chan->n_cpus * sizeof(int)); + if(chan->buf_struct_shmids == NULL) goto free_buf; - result = ust_buffers_alloc_channel_buf_structs(ltt_chan); + result = map_buf_structs(chan); if(result != 0) { goto free_buf_struct_shmids; } - result = ust_buffers_channel_open(ltt_chan, subbuf_size, n_subbufs); + result = open_channel(chan, subbuf_size, n_subbufs); if (result != 0) { ERR("Cannot open channel for trace %s", trace_name); - goto unalloc_buf_structs; + goto unmap_buf_structs; } return 0; -unalloc_buf_structs: - /* FIXME: put a call here to unalloc the buf structs! */ +unmap_buf_structs: + for (i=0; i < chan->n_cpus; i++) { + if (shmdt(chan->buf[i]) < 0) { + PERROR("shmdt bufstruct"); + } + } free_buf_struct_shmids: - free(ltt_chan->buf_struct_shmids); + free(chan->buf_struct_shmids); free_buf: - free(ltt_chan->buf); + free(chan->buf); error: return -1; } -/* - * LTTng channel flush function. - * - * Must be called when no tracing is active in the channel, because of - * accesses across CPUs. - */ -static notrace void ltt_relay_buffer_flush(struct ust_buffer *buf) + +static void remove_channel(struct ust_channel *chan) { - int result; + close_channel(chan); -//ust// buf->finalized = 1; - ltt_force_switch(buf, FORCE_FLUSH); + unmap_buf_structs(chan); - result = write(buf->data_ready_fd_write, "1", 1); - if(result == -1) { - PERROR("write (in ltt_relay_buffer_flush)"); - ERR("this should never happen!"); - } + free(chan->buf_struct_shmids); + + free(chan->buf); } static void ltt_relay_async_wakeup_chan(struct ust_channel *ltt_channel) { -//ust// unsigned int i; -//ust// struct rchan *rchan = ltt_channel->trans_channel_data; -//ust// -//ust// for_each_possible_cpu(i) { -//ust// struct ltt_channel_buf_struct *ltt_buf = -//ust// percpu_ptr(ltt_channel->buf, i); -//ust// -//ust// if (uatomic_read(<t_buf->wakeup_readers) == 1) { -//ust// uatomic_set(<t_buf->wakeup_readers, 0); -//ust// wake_up_interruptible(&rchan->buf[i]->read_wait); -//ust// } -//ust// } } static void ltt_relay_finish_buffer(struct ust_channel *channel, unsigned int cpu) { -// int result; - if (channel->buf[cpu]) { struct ust_buffer *buf = channel->buf[cpu]; - ltt_relay_buffer_flush(buf); -//ust// ltt_relay_wake_writers(ltt_buf); + ltt_force_switch(buf, FORCE_FLUSH); + /* closing the pipe tells the consumer the buffer is finished */ - - //result = write(ltt_buf->data_ready_fd_write, "D", 1); - //if(result == -1) { - // PERROR("write (in ltt_relay_finish_buffer)"); - // ERR("this should never happen!"); - //} close(buf->data_ready_fd_write); } } -static void ltt_relay_finish_channel(struct ust_channel *channel) +static void finish_channel(struct ust_channel *channel) { unsigned int i; - for(i=0; in_cpus; i++) { + for (i=0; in_cpus; i++) { ltt_relay_finish_buffer(channel, i); } } -static void ltt_relay_remove_channel(struct ust_channel *channel) -{ - ust_buffers_channel_close(channel); - kref_put(&channel->kref, ltt_relay_release_channel); -} - -//ust// /* -//ust// * Returns : -//ust// * 0 if ok -//ust// * !0 if execution must be aborted. -//ust// */ -//ust// static inline int ltt_relay_try_reserve( -//ust// struct ust_channel *channel, struct ust_buffer *buf, -//ust// struct ltt_reserve_switch_offsets *offsets, size_t data_size, -//ust// u64 *tsc, unsigned int *rflags, int largest_align) -//ust// { -//ust// offsets->begin = uatomic_read(&buf->offset); -//ust// offsets->old = offsets->begin; -//ust// offsets->begin_switch = 0; -//ust// offsets->end_switch_current = 0; -//ust// offsets->end_switch_old = 0; -//ust// -//ust// *tsc = trace_clock_read64(); -//ust// if (last_tsc_overflow(buf, *tsc)) -//ust// *rflags = LTT_RFLAG_ID_SIZE_TSC; -//ust// -//ust// if (SUBBUF_OFFSET(offsets->begin, buf->chan) == 0) { -//ust// offsets->begin_switch = 1; /* For offsets->begin */ -//ust// } else { -//ust// offsets->size = ust_get_header_size(channel, -//ust// offsets->begin, data_size, -//ust// &offsets->before_hdr_pad, *rflags); -//ust// offsets->size += ltt_align(offsets->begin + offsets->size, -//ust// largest_align) -//ust// + data_size; -//ust// if ((SUBBUF_OFFSET(offsets->begin, buf->chan) + offsets->size) -//ust// > buf->chan->subbuf_size) { -//ust// offsets->end_switch_old = 1; /* For offsets->old */ -//ust// offsets->begin_switch = 1; /* For offsets->begin */ -//ust// } -//ust// } -//ust// if (offsets->begin_switch) { -//ust// long subbuf_index; -//ust// -//ust// if (offsets->end_switch_old) -//ust// offsets->begin = SUBBUF_ALIGN(offsets->begin, -//ust// buf->chan); -//ust// offsets->begin = offsets->begin + ltt_subbuffer_header_size(); -//ust// /* Test new buffer integrity */ -//ust// subbuf_index = SUBBUF_INDEX(offsets->begin, buf->chan); -//ust// offsets->reserve_commit_diff = -//ust// (BUFFER_TRUNC(offsets->begin, buf->chan) -//ust// >> channel->n_subbufs_order) -//ust// - (uatomic_read(&buf->commit_count[subbuf_index]) -//ust// & channel->commit_count_mask); -//ust// if (offsets->reserve_commit_diff == 0) { -//ust// long consumed; -//ust// -//ust// consumed = uatomic_read(&buf->consumed); -//ust// -//ust// /* Next buffer not corrupted. */ -//ust// if (!channel->overwrite && -//ust// (SUBBUF_TRUNC(offsets->begin, buf->chan) -//ust// - SUBBUF_TRUNC(consumed, buf->chan)) -//ust// >= channel->alloc_size) { -//ust// -//ust// long consumed_idx = SUBBUF_INDEX(consumed, buf->chan); -//ust// long commit_count = uatomic_read(&buf->commit_count[consumed_idx]); -//ust// if(((commit_count - buf->chan->subbuf_size) & channel->commit_count_mask) - (BUFFER_TRUNC(consumed, buf->chan) >> channel->n_subbufs_order) != 0) { -//ust// WARN("Event dropped. Caused by non-committed event."); -//ust// } -//ust// else { -//ust// WARN("Event dropped. Caused by non-consumed buffer."); -//ust// } -//ust// /* -//ust// * We do not overwrite non consumed buffers -//ust// * and we are full : event is lost. -//ust// */ -//ust// uatomic_inc(&buf->events_lost); -//ust// return -1; -//ust// } else { -//ust// /* -//ust// * next buffer not corrupted, we are either in -//ust// * overwrite mode or the buffer is not full. -//ust// * It's safe to write in this new subbuffer. -//ust// */ -//ust// } -//ust// } else { -//ust// /* -//ust// * Next subbuffer corrupted. Force pushing reader even -//ust// * in normal mode. It's safe to write in this new -//ust// * subbuffer. -//ust// */ -//ust// } -//ust// offsets->size = ust_get_header_size(channel, -//ust// offsets->begin, data_size, -//ust// &offsets->before_hdr_pad, *rflags); -//ust// offsets->size += ltt_align(offsets->begin + offsets->size, -//ust// largest_align) -//ust// + data_size; -//ust// if ((SUBBUF_OFFSET(offsets->begin, buf->chan) + offsets->size) -//ust// > buf->chan->subbuf_size) { -//ust// /* -//ust// * Event too big for subbuffers, report error, don't -//ust// * complete the sub-buffer switch. -//ust// */ -//ust// uatomic_inc(&buf->events_lost); -//ust// return -1; -//ust// } else { -//ust// /* -//ust// * We just made a successful buffer switch and the event -//ust// * fits in the new subbuffer. Let's write. -//ust// */ -//ust// } -//ust// } else { -//ust// /* -//ust// * Event fits in the current buffer and we are not on a switch -//ust// * boundary. It's safe to write. -//ust// */ -//ust// } -//ust// offsets->end = offsets->begin + offsets->size; -//ust// -//ust// if ((SUBBUF_OFFSET(offsets->end, buf->chan)) == 0) { -//ust// /* -//ust// * The offset_end will fall at the very beginning of the next -//ust// * subbuffer. -//ust// */ -//ust// offsets->end_switch_current = 1; /* For offsets->begin */ -//ust// } -//ust// return 0; -//ust// } -//ust// -//ust// /* -//ust// * Returns : -//ust// * 0 if ok -//ust// * !0 if execution must be aborted. -//ust// */ -//ust// static inline int ltt_relay_try_switch( -//ust// enum force_switch_mode mode, -//ust// struct ust_channel *channel, -//ust// struct ust_buffer *buf, -//ust// struct ltt_reserve_switch_offsets *offsets, -//ust// u64 *tsc) -//ust// { -//ust// long subbuf_index; -//ust// -//ust// offsets->begin = uatomic_read(&buf->offset); -//ust// offsets->old = offsets->begin; -//ust// offsets->begin_switch = 0; -//ust// offsets->end_switch_old = 0; -//ust// -//ust// *tsc = trace_clock_read64(); -//ust// -//ust// if (SUBBUF_OFFSET(offsets->begin, buf->chan) != 0) { -//ust// offsets->begin = SUBBUF_ALIGN(offsets->begin, buf->chan); -//ust// offsets->end_switch_old = 1; -//ust// } else { -//ust// /* we do not have to switch : buffer is empty */ -//ust// return -1; -//ust// } -//ust// if (mode == FORCE_ACTIVE) -//ust// offsets->begin += ltt_subbuffer_header_size(); -//ust// /* -//ust// * Always begin_switch in FORCE_ACTIVE mode. -//ust// * Test new buffer integrity -//ust// */ -//ust// subbuf_index = SUBBUF_INDEX(offsets->begin, buf->chan); -//ust// offsets->reserve_commit_diff = -//ust// (BUFFER_TRUNC(offsets->begin, buf->chan) -//ust// >> channel->n_subbufs_order) -//ust// - (uatomic_read(&buf->commit_count[subbuf_index]) -//ust// & channel->commit_count_mask); -//ust// if (offsets->reserve_commit_diff == 0) { -//ust// /* Next buffer not corrupted. */ -//ust// if (mode == FORCE_ACTIVE -//ust// && !channel->overwrite -//ust// && offsets->begin - uatomic_read(&buf->consumed) -//ust// >= channel->alloc_size) { -//ust// /* -//ust// * We do not overwrite non consumed buffers and we are -//ust// * full : ignore switch while tracing is active. -//ust// */ -//ust// return -1; -//ust// } -//ust// } else { -//ust// /* -//ust// * Next subbuffer corrupted. Force pushing reader even in normal -//ust// * mode -//ust// */ -//ust// } -//ust// offsets->end = offsets->begin; -//ust// return 0; -//ust// } -//ust// -//ust// static inline void ltt_reserve_push_reader( -//ust// struct ust_channel *channel, -//ust// struct ust_buffer *buf, -//ust// struct ltt_reserve_switch_offsets *offsets) -//ust// { -//ust// long consumed_old, consumed_new; -//ust// -//ust// do { -//ust// consumed_old = uatomic_read(&buf->consumed); -//ust// /* -//ust// * If buffer is in overwrite mode, push the reader consumed -//ust// * count if the write position has reached it and we are not -//ust// * at the first iteration (don't push the reader farther than -//ust// * the writer). This operation can be done concurrently by many -//ust// * writers in the same buffer, the writer being at the farthest -//ust// * write position sub-buffer index in the buffer being the one -//ust// * which will win this loop. -//ust// * If the buffer is not in overwrite mode, pushing the reader -//ust// * only happens if a sub-buffer is corrupted. -//ust// */ -//ust// if ((SUBBUF_TRUNC(offsets->end-1, buf->chan) -//ust// - SUBBUF_TRUNC(consumed_old, buf->chan)) -//ust// >= channel->alloc_size) -//ust// consumed_new = SUBBUF_ALIGN(consumed_old, buf->chan); -//ust// else { -//ust// consumed_new = consumed_old; -//ust// break; -//ust// } -//ust// } while (uatomic_cmpxchg(&buf->consumed, consumed_old, -//ust// consumed_new) != consumed_old); -//ust// -//ust// if (consumed_old != consumed_new) { -//ust// /* -//ust// * Reader pushed : we are the winner of the push, we can -//ust// * therefore reequilibrate reserve and commit. Atomic increment -//ust// * of the commit count permits other writers to play around -//ust// * with this variable before us. We keep track of -//ust// * corrupted_subbuffers even in overwrite mode : -//ust// * we never want to write over a non completely committed -//ust// * sub-buffer : possible causes : the buffer size is too low -//ust// * compared to the unordered data input, or there is a writer -//ust// * that died between the reserve and the commit. -//ust// */ -//ust// if (offsets->reserve_commit_diff) { -//ust// /* -//ust// * We have to alter the sub-buffer commit count. -//ust// * We do not deliver the previous subbuffer, given it -//ust// * was either corrupted or not consumed (overwrite -//ust// * mode). -//ust// */ -//ust// uatomic_add(&buf->commit_count[SUBBUF_INDEX(offsets->begin, buf->chan)], -//ust// offsets->reserve_commit_diff); -//ust// if (!channel->overwrite -//ust// || offsets->reserve_commit_diff -//ust// != channel->subbuf_size) { -//ust// /* -//ust// * The reserve commit diff was not subbuf_size : -//ust// * it means the subbuffer was partly written to -//ust// * and is therefore corrupted. If it is multiple -//ust// * of subbuffer size and we are in flight -//ust// * recorder mode, we are skipping over a whole -//ust// * subbuffer. -//ust// */ -//ust// uatomic_inc(&buf->corrupted_subbuffers); -//ust// } -//ust// } -//ust// } -//ust// } -//ust// -//ust// /** -//ust// * ltt_relay_reserve_slot - Atomic slot reservation in a LTTng buffer. -//ust// * @trace: the trace structure to log to. -//ust// * @ltt_channel: channel structure -//ust// * @transport_data: data structure specific to ltt relay -//ust// * @data_size: size of the variable length data to log. -//ust// * @slot_size: pointer to total size of the slot (out) -//ust// * @buf_offset : pointer to reserved buffer offset (out) -//ust// * @tsc: pointer to the tsc at the slot reservation (out) -//ust// * @cpu: cpuid -//ust// * -//ust// * Return : -ENOSPC if not enough space, else returns 0. -//ust// * It will take care of sub-buffer switching. -//ust// */ -//ust// static notrace int ltt_relay_reserve_slot(struct ust_trace *trace, -//ust// struct ust_channel *channel, void **transport_data, -//ust// size_t data_size, size_t *slot_size, long *buf_offset, u64 *tsc, -//ust// unsigned int *rflags, int largest_align, int cpu) -//ust// { -//ust// struct ust_buffer *buf = *transport_data = channel->buf[cpu]; -//ust// struct ltt_reserve_switch_offsets offsets; -//ust// -//ust// offsets.reserve_commit_diff = 0; -//ust// offsets.size = 0; -//ust// -//ust// /* -//ust// * Perform retryable operations. -//ust// */ -//ust// if (ltt_nesting > 4) { -//ust// uatomic_inc(&buf->events_lost); -//ust// return -EPERM; -//ust// } -//ust// do { -//ust// if (ltt_relay_try_reserve(channel, buf, &offsets, data_size, tsc, rflags, -//ust// largest_align)) -//ust// return -ENOSPC; -//ust// } while (uatomic_cmpxchg(&buf->offset, offsets.old, -//ust// offsets.end) != offsets.old); -//ust// -//ust// /* -//ust// * Atomically update last_tsc. This update races against concurrent -//ust// * atomic updates, but the race will always cause supplementary full TSC -//ust// * events, never the opposite (missing a full TSC event when it would be -//ust// * needed). -//ust// */ -//ust// save_last_tsc(buf, *tsc); -//ust// -//ust// /* -//ust// * Push the reader if necessary -//ust// */ -//ust// ltt_reserve_push_reader(channel, buf, &offsets); -//ust// -//ust// /* -//ust// * Switch old subbuffer if needed. -//ust// */ -//ust// if (offsets.end_switch_old) -//ust// ltt_reserve_switch_old_subbuf(channel, buf, &offsets, tsc); -//ust// -//ust// /* -//ust// * Populate new subbuffer. -//ust// */ -//ust// if (offsets.begin_switch) -//ust// ltt_reserve_switch_new_subbuf(channel, buf, &offsets, tsc); -//ust// -//ust// if (offsets.end_switch_current) -//ust// ltt_reserve_end_switch_current(channel, buf, &offsets, tsc); -//ust// -//ust// *slot_size = offsets.size; -//ust// *buf_offset = offsets.begin + offsets.before_hdr_pad; -//ust// return 0; -//ust// } -//ust// -//ust// /* -//ust// * Force a sub-buffer switch for a per-cpu buffer. This operation is -//ust// * completely reentrant : can be called while tracing is active with -//ust// * absolutely no lock held. -//ust// */ -//ust// static notrace void ltt_force_switch(struct ust_buffer *buf, -//ust// enum force_switch_mode mode) -//ust// { -//ust// struct ust_channel *channel = buf->chan; -//ust// struct ltt_reserve_switch_offsets offsets; -//ust// u64 tsc; -//ust// -//ust// offsets.reserve_commit_diff = 0; -//ust// offsets.size = 0; -//ust// -//ust// /* -//ust// * Perform retryable operations. -//ust// */ -//ust// do { -//ust// if (ltt_relay_try_switch(mode, channel, buf, &offsets, &tsc)) -//ust// return; -//ust// } while (uatomic_cmpxchg(&buf->offset, offsets.old, -//ust// offsets.end) != offsets.old); -//ust// -//ust// /* -//ust// * Atomically update last_tsc. This update races against concurrent -//ust// * atomic updates, but the race will always cause supplementary full TSC -//ust// * events, never the opposite (missing a full TSC event when it would be -//ust// * needed). -//ust// */ -//ust// save_last_tsc(buf, tsc); -//ust// -//ust// /* -//ust// * Push the reader if necessary -//ust// */ -//ust// if (mode == FORCE_ACTIVE) -//ust// ltt_reserve_push_reader(channel, buf, &offsets); -//ust// -//ust// /* -//ust// * Switch old subbuffer if needed. -//ust// */ -//ust// if (offsets.end_switch_old) -//ust// ltt_reserve_switch_old_subbuf(channel, buf, &offsets, &tsc); -//ust// -//ust// /* -//ust// * Populate new subbuffer. -//ust// */ -//ust// if (mode == FORCE_ACTIVE) -//ust// ltt_reserve_switch_new_subbuf(channel, buf, &offsets, &tsc); -//ust// } /* * ltt_reserve_switch_old_subbuf: switch old subbuffer @@ -1349,10 +675,10 @@ static void ltt_reserve_switch_old_subbuf( /* * Must write slot data before incrementing commit count. - * This compiler barrier is upgraded into a smp_wmb() by the IPI - * sent by get_subbuf() when it does its smp_rmb(). + * This compiler barrier is upgraded into a cmm_smp_wmb() by the IPI + * sent by get_subbuf() when it does its cmm_smp_rmb(). */ - barrier(); + cmm_smp_wmb(); uatomic_add(&buf->commit_count[oldidx].cc, padding_size); commit_count = uatomic_read(&buf->commit_count[oldidx].cc); ltt_check_deliver(chan, buf, offsets->old - 1, commit_count, oldidx); @@ -1378,10 +704,10 @@ static void ltt_reserve_switch_new_subbuf( /* * Must write slot data before incrementing commit count. - * This compiler barrier is upgraded into a smp_wmb() by the IPI - * sent by get_subbuf() when it does its smp_rmb(). + * This compiler barrier is upgraded into a cmm_smp_wmb() by the IPI + * sent by get_subbuf() when it does its cmm_smp_rmb(). */ - barrier(); + cmm_smp_wmb(); uatomic_add(&buf->commit_count[beginidx].cc, ltt_subbuffer_header_size()); commit_count = uatomic_read(&buf->commit_count[beginidx].cc); /* Check if the written buffer has to be delivered */ @@ -1423,10 +749,10 @@ static void ltt_reserve_end_switch_current( /* * Must write slot data before incrementing commit count. - * This compiler barrier is upgraded into a smp_wmb() by the IPI - * sent by get_subbuf() when it does its smp_rmb(). + * This compiler barrier is upgraded into a cmm_smp_wmb() by the IPI + * sent by get_subbuf() when it does its cmm_smp_rmb(). */ - barrier(); + cmm_smp_wmb(); uatomic_add(&buf->commit_count[endidx].cc, padding_size); commit_count = uatomic_read(&buf->commit_count[endidx].cc); ltt_check_deliver(chan, buf, @@ -1536,14 +862,12 @@ void ltt_force_switch_lockless_slow(struct ust_buffer *buf, */ if (mode == FORCE_ACTIVE) { ltt_reserve_push_reader(chan, buf, offsets.end - 1); -//ust// ltt_clear_noref_flag(chan, buf, SUBBUF_INDEX(offsets.end - 1, chan)); } /* * Switch old subbuffer if needed. */ if (offsets.end_switch_old) { -//ust// ltt_clear_noref_flag(rchan, buf, SUBBUF_INDEX(offsets.old - 1, rchan)); ltt_reserve_switch_old_subbuf(chan, buf, &offsets, &tsc); } @@ -1689,12 +1013,14 @@ static int ltt_relay_try_reserve_slow(struct ust_channel *chan, struct ust_buffe * Return : -ENOSPC if not enough space, else returns 0. * It will take care of sub-buffer switching. */ -int ltt_reserve_slot_lockless_slow(struct ust_trace *trace, - struct ust_channel *chan, void **transport_data, - size_t data_size, size_t *slot_size, long *buf_offset, u64 *tsc, - unsigned int *rflags, int largest_align, int cpu) +int ltt_reserve_slot_lockless_slow(struct ust_channel *chan, + struct ust_trace *trace, size_t data_size, + int largest_align, int cpu, + struct ust_buffer **ret_buf, + size_t *slot_size, long *buf_offset, + u64 *tsc, unsigned int *rflags) { - struct ust_buffer *buf = chan->buf[cpu]; + struct ust_buffer *buf = *ret_buf = chan->buf[cpu]; struct ltt_reserve_switch_offsets offsets; offsets.size = 0; @@ -1719,16 +1045,10 @@ int ltt_reserve_slot_lockless_slow(struct ust_trace *trace, */ ltt_reserve_push_reader(chan, buf, offsets.end - 1); - /* - * Clear noref flag for this subbuffer. - */ -//ust// ltt_clear_noref_flag(chan, buf, SUBBUF_INDEX(offsets.end - 1, chan)); - /* * Switch old subbuffer if needed. */ if (unlikely(offsets.end_switch_old)) { -//ust// ltt_clear_noref_flag(chan, buf, SUBBUF_INDEX(offsets.old - 1, chan)); ltt_reserve_switch_old_subbuf(chan, buf, &offsets, tsc); DBG("Switching %s_%d", chan->channel_name, cpu); } @@ -1750,9 +1070,9 @@ int ltt_reserve_slot_lockless_slow(struct ust_trace *trace, static struct ltt_transport ust_relay_transport = { .name = "ustrelay", .ops = { - .create_channel = ust_buffers_create_channel, - .finish_channel = ltt_relay_finish_channel, - .remove_channel = ltt_relay_remove_channel, + .create_channel = create_channel, + .finish_channel = finish_channel, + .remove_channel = remove_channel, .wakeup_channel = ltt_relay_async_wakeup_chan, }, }; @@ -1772,8 +1092,7 @@ static void __attribute__((destructor)) ust_buffers_exit(void) ltt_transport_unregister(&ust_relay_transport); } -size_t ltt_write_event_header_slow(struct ust_trace *trace, - struct ust_channel *channel, +size_t ltt_write_event_header_slow(struct ust_channel *channel, struct ust_buffer *buf, long buf_offset, u16 eID, u32 event_size, u64 tsc, unsigned int rflags) @@ -1791,6 +1110,10 @@ size_t ltt_write_event_header_slow(struct ust_trace *trace, case LTT_RFLAG_ID: header.id_time = 31 << LTT_TSC_BITS; break; + default: + WARN_ON_ONCE(1); + header.id_time = 0; + break; } header.id_time |= (u32)tsc & LTT_TSC_MASK;