Hi Steven, Em Fri, 01 Mar 2013 21:48:38 -0500 Steven Rostedt <[email protected]> escreveu:
> From: Steven Rostedt <[email protected]> > > The trace_pipe_raw never implemented polling and this was casing > issues for several utilities. This is now implemented. > > Blocked reads still are on the TODO list. I tested it and it works fine. > Reported-by: Mauro Carvalho Chehab <[email protected]> Tested-by: Mauro Carvalho Chehab <[email protected]> > Signed-off-by: Steven Rostedt <[email protected]> > --- > kernel/trace/trace.c | 78 > +++++++++++++++++++++++++++++++++----------------- > 1 file changed, 51 insertions(+), 27 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 00e5e6e..b958e9d 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -3503,10 +3503,8 @@ static int tracing_release_pipe(struct inode *inode, > struct file *file) > } > > static unsigned int > -tracing_poll_pipe(struct file *filp, poll_table *poll_table) > +trace_poll(struct trace_iterator *iter, struct file *filp, poll_table > *poll_table) > { > - struct trace_iterator *iter = filp->private_data; > - > if (trace_flags & TRACE_ITER_BLOCK) { > /* > * Always select as readable when in blocking mode > @@ -3515,6 +3513,7 @@ tracing_poll_pipe(struct file *filp, poll_table > *poll_table) > } else { > if (!trace_empty(iter)) > return POLLIN | POLLRDNORM; > + trace_wakeup_needed = true; > poll_wait(filp, &trace_wait, poll_table); > if (!trace_empty(iter)) > return POLLIN | POLLRDNORM; > @@ -3523,6 +3522,14 @@ tracing_poll_pipe(struct file *filp, poll_table > *poll_table) > } > } > > +static unsigned int > +tracing_poll_pipe(struct file *filp, poll_table *poll_table) > +{ > + struct trace_iterator *iter = filp->private_data; > + > + return trace_poll(iter, filp, poll_table); > +} > + > /* > * This is a make-shift waitqueue. > * A tracer might use this callback on some rare cases: > @@ -4312,9 +4319,8 @@ static const struct file_operations snapshot_fops = { > #endif /* CONFIG_TRACER_SNAPSHOT */ > > struct ftrace_buffer_info { > - struct trace_array *tr; > + struct trace_iterator iter; > void *spare; > - int cpu; > unsigned int read; > }; > > @@ -4331,22 +4337,32 @@ static int tracing_buffers_open(struct inode *inode, > struct file *filp) > if (!info) > return -ENOMEM; > > - info->tr = tr; > - info->cpu = tc->cpu; > - info->spare = NULL; > + info->iter.tr = tr; > + info->iter.cpu_file = tc->cpu; > + info->spare = NULL; > /* Force reading ring buffer for first read */ > - info->read = (unsigned int)-1; > + info->read = (unsigned int)-1; > > filp->private_data = info; > > return nonseekable_open(inode, filp); > } > > +static unsigned int > +tracing_buffers_poll(struct file *filp, poll_table *poll_table) > +{ > + struct ftrace_buffer_info *info = filp->private_data; > + struct trace_iterator *iter = &info->iter; > + > + return trace_poll(iter, filp, poll_table); > +} > + > static ssize_t > tracing_buffers_read(struct file *filp, char __user *ubuf, > size_t count, loff_t *ppos) > { > struct ftrace_buffer_info *info = filp->private_data; > + struct trace_iterator *iter = &info->iter; > ssize_t ret; > size_t size; > > @@ -4354,7 +4370,7 @@ tracing_buffers_read(struct file *filp, char __user > *ubuf, > return 0; > > if (!info->spare) > - info->spare = ring_buffer_alloc_read_page(info->tr->buffer, > info->cpu); > + info->spare = ring_buffer_alloc_read_page(iter->tr->buffer, > iter->cpu_file); > if (!info->spare) > return -ENOMEM; > > @@ -4362,12 +4378,12 @@ tracing_buffers_read(struct file *filp, char __user > *ubuf, > if (info->read < PAGE_SIZE) > goto read; > > - trace_access_lock(info->cpu); > - ret = ring_buffer_read_page(info->tr->buffer, > + trace_access_lock(iter->cpu_file); > + ret = ring_buffer_read_page(iter->tr->buffer, > &info->spare, > count, > - info->cpu, 0); > - trace_access_unlock(info->cpu); > + iter->cpu_file, 0); > + trace_access_unlock(iter->cpu_file); > if (ret < 0) > return 0; > > @@ -4392,9 +4408,10 @@ read: > static int tracing_buffers_release(struct inode *inode, struct file *file) > { > struct ftrace_buffer_info *info = file->private_data; > + struct trace_iterator *iter = &info->iter; > > if (info->spare) > - ring_buffer_free_read_page(info->tr->buffer, info->spare); > + ring_buffer_free_read_page(iter->tr->buffer, info->spare); > kfree(info); > > return 0; > @@ -4461,6 +4478,7 @@ tracing_buffers_splice_read(struct file *file, loff_t > *ppos, > unsigned int flags) > { > struct ftrace_buffer_info *info = file->private_data; > + struct trace_iterator *iter = &info->iter; > struct partial_page partial_def[PIPE_DEF_BUFFERS]; > struct page *pages_def[PIPE_DEF_BUFFERS]; > struct splice_pipe_desc spd = { > @@ -4491,8 +4509,9 @@ tracing_buffers_splice_read(struct file *file, loff_t > *ppos, > len &= PAGE_MASK; > } > > - trace_access_lock(info->cpu); > - entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); > + again: > + trace_access_lock(iter->cpu_file); > + entries = ring_buffer_entries_cpu(iter->tr->buffer, iter->cpu_file); > > for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) > { > struct page *page; > @@ -4503,15 +4522,15 @@ tracing_buffers_splice_read(struct file *file, loff_t > *ppos, > break; > > ref->ref = 1; > - ref->buffer = info->tr->buffer; > - ref->page = ring_buffer_alloc_read_page(ref->buffer, info->cpu); > + ref->buffer = iter->tr->buffer; > + ref->page = ring_buffer_alloc_read_page(ref->buffer, > iter->cpu_file); > if (!ref->page) { > kfree(ref); > break; > } > > r = ring_buffer_read_page(ref->buffer, &ref->page, > - len, info->cpu, 1); > + len, iter->cpu_file, 1); > if (r < 0) { > ring_buffer_free_read_page(ref->buffer, ref->page); > kfree(ref); > @@ -4535,20 +4554,24 @@ tracing_buffers_splice_read(struct file *file, loff_t > *ppos, > spd.nr_pages++; > *ppos += PAGE_SIZE; > > - entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); > + entries = ring_buffer_entries_cpu(iter->tr->buffer, > iter->cpu_file); > } > > - trace_access_unlock(info->cpu); > + trace_access_unlock(iter->cpu_file); > spd.nr_pages = i; > > /* did we read anything? */ > if (!spd.nr_pages) { > - if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) > + if ((file->f_flags & O_NONBLOCK) || (flags & > SPLICE_F_NONBLOCK)) { > ret = -EAGAIN; > - else > - ret = 0; > - /* TODO: block */ > - goto out; > + goto out; > + } > + default_wait_pipe(iter); > + if (signal_pending(current)) { > + ret = -EINTR; > + goto out; > + } > + goto again; > } > > ret = splice_to_pipe(pipe, &spd); > @@ -4560,6 +4583,7 @@ out: > static const struct file_operations tracing_buffers_fops = { > .open = tracing_buffers_open, > .read = tracing_buffers_read, > + .poll = tracing_buffers_poll, > .release = tracing_buffers_release, > .splice_read = tracing_buffers_splice_read, > .llseek = no_llseek, -- Cheers, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
