ring-buffer: Merge separate resize loops

There are 2 separate loops to resize cpu buffers that are online and
offline. Merge them to make the code look better.

Also change the name from update_completion to update_done to allow
shorter lines.

Link: http://lkml.kernel.org/r/1337372991-14783-1-git-send-email-vnagarnaik@google.com
Cc: Laurent Chavey <chavey@google.com>
Cc: Justin Teravest <teravest@google.com>
Cc: David Sharp <dhsharp@google.com>
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 68388f8..6420cda 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -473,7 +473,7 @@ struct ring_buffer_per_cpu {
        int                             nr_pages_to_update;
        struct list_head                new_pages; /* new pages to add */
        struct work_struct              update_pages_work;
-       struct completion               update_completion;
+       struct completion               update_done;
 };
 
 struct ring_buffer {
@@ -1058,7 +1058,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int nr_pages, int cpu)
        lockdep_set_class(&cpu_buffer->reader_lock, buffer->reader_lock_key);
        cpu_buffer->lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
        INIT_WORK(&cpu_buffer->update_pages_work, update_pages_handler);
-       init_completion(&cpu_buffer->update_completion);
+       init_completion(&cpu_buffer->update_done);
 
        bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
                            GFP_KERNEL, cpu_to_node(cpu));
@@ -1461,7 +1461,7 @@ static void update_pages_handler(struct work_struct *work)
        struct ring_buffer_per_cpu *cpu_buffer = container_of(work,
                        struct ring_buffer_per_cpu, update_pages_work);
        rb_update_pages(cpu_buffer);
-       complete(&cpu_buffer->update_completion);
+       complete(&cpu_buffer->update_done);
 }
 
 /**
@@ -1534,39 +1534,29 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
                get_online_cpus();
                /*
                 * Fire off all the required work handlers
-                * Look out for offline CPUs
-                */
-               for_each_buffer_cpu(buffer, cpu) {
-                       cpu_buffer = buffer->buffers[cpu];
-                       if (!cpu_buffer->nr_pages_to_update ||
-                           !cpu_online(cpu))
-                               continue;
-
-                       schedule_work_on(cpu, &cpu_buffer->update_pages_work);
-               }
-               /*
-                * This loop is for the CPUs that are not online.
-                * We can't schedule anything on them, but it's not necessary
+                * We can't schedule on offline CPUs, but it's not necessary
                 * since we can change their buffer sizes without any race.
                 */
                for_each_buffer_cpu(buffer, cpu) {
                        cpu_buffer = buffer->buffers[cpu];
-                       if (!cpu_buffer->nr_pages_to_update ||
-                           cpu_online(cpu))
+                       if (!cpu_buffer->nr_pages_to_update)
                                continue;
 
-                       rb_update_pages(cpu_buffer);
+                       if (cpu_online(cpu))
+                               schedule_work_on(cpu,
+                                               &cpu_buffer->update_pages_work);
+                       else
+                               rb_update_pages(cpu_buffer);
                }
 
                /* wait for all the updates to complete */
                for_each_buffer_cpu(buffer, cpu) {
                        cpu_buffer = buffer->buffers[cpu];
-                       if (!cpu_buffer->nr_pages_to_update ||
-                           !cpu_online(cpu))
+                       if (!cpu_buffer->nr_pages_to_update)
                                continue;
 
-                       wait_for_completion(&cpu_buffer->update_completion);
-                       /* reset this value */
+                       if (cpu_online(cpu))
+                               wait_for_completion(&cpu_buffer->update_done);
                        cpu_buffer->nr_pages_to_update = 0;
                }
 
@@ -1593,13 +1583,12 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
                if (cpu_online(cpu_id)) {
                        schedule_work_on(cpu_id,
                                         &cpu_buffer->update_pages_work);
-                       wait_for_completion(&cpu_buffer->update_completion);
+                       wait_for_completion(&cpu_buffer->update_done);
                } else
                        rb_update_pages(cpu_buffer);
 
-               put_online_cpus();
-               /* reset this value */
                cpu_buffer->nr_pages_to_update = 0;
+               put_online_cpus();
        }
 
  out: