cpumask: convert kernel trace functions

Impact: Reduce future memory usage, use new cpumask API.

(Eventually, cpumask_var_t will be allocated based on nr_cpu_ids, not NR_CPUS).

Convert kernel trace functions to use struct cpumask API:
1) Use cpumask_copy/cpumask_test_cpu/for_each_cpu.
2) Use cpumask_var_t and alloc_cpumask_var/free_cpumask_var everywhere.
3) Use on_each_cpu instead of playing with current->cpus_allowed.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 25 insertions, 17 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 1d601a7c4587..a9d9760dc7b6 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -195,7 +195,7 @@ void *ring_buffer_event_data(struct ring_buffer_event *event)
 EXPORT_SYMBOL_GPL(ring_buffer_event_data);
 
 #define for_each_buffer_cpu(buffer, cpu)                \
-        for_each_cpu_mask(cpu, buffer->cpumask)
+        for_each_cpu(cpu, buffer->cpumask)
 
 #define TS_SHIFT        27
 #define TS_MASK         ((1ULL << TS_SHIFT) - 1)
@@ -267,7 +267,7 @@ struct ring_buffer {
         unsigned                        pages;
         unsigned                        flags;
         int                             cpus;
-        cpumask_t                       cpumask;
+        cpumask_var_t                   cpumask;
         atomic_t                        record_disabled;
 
         struct mutex                    mutex;
@@ -458,6 +458,9 @@ struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags)
         if (!buffer)
                 return NULL;
 
+        if (!alloc_cpumask_var(&buffer->cpumask, GFP_KERNEL))
+                goto fail_free_buffer;
+
         buffer->pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
         buffer->flags = flags;
 
@@ -465,14 +468,14 @@ struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags)
         if (buffer->pages == 1)
                 buffer->pages++;
 
-        buffer->cpumask = cpu_possible_map;
+        cpumask_copy(buffer->cpumask, cpu_possible_mask);
         buffer->cpus = nr_cpu_ids;
 
         bsize = sizeof(void *) * nr_cpu_ids;
         buffer->buffers = kzalloc(ALIGN(bsize, cache_line_size()),
                                   GFP_KERNEL);
         if (!buffer->buffers)
-                goto fail_free_buffer;
+                goto fail_free_cpumask;
 
         for_each_buffer_cpu(buffer, cpu) {
                 buffer->buffers[cpu] =
@@ -492,6 +495,9 @@ struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags)
         }
         kfree(buffer->buffers);
 
+ fail_free_cpumask:
+        free_cpumask_var(buffer->cpumask);
+
  fail_free_buffer:
         kfree(buffer);
         return NULL;
@@ -510,6 +516,8 @@ ring_buffer_free(struct ring_buffer *buffer)
         for_each_buffer_cpu(buffer, cpu)
                 rb_free_cpu_buffer(buffer->buffers[cpu]);
 
+        free_cpumask_var(buffer->cpumask);
+
         kfree(buffer);
 }
 EXPORT_SYMBOL_GPL(ring_buffer_free);
@@ -1283,7 +1291,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
 
         cpu = raw_smp_processor_id();
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 goto out;
 
         cpu_buffer = buffer->buffers[cpu];
@@ -1396,7 +1404,7 @@ int ring_buffer_write(struct ring_buffer *buffer,
 
         cpu = raw_smp_processor_id();
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 goto out;
 
         cpu_buffer = buffer->buffers[cpu];
@@ -1478,7 +1486,7 @@ void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu)
 {
         struct ring_buffer_per_cpu *cpu_buffer;
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 return;
 
         cpu_buffer = buffer->buffers[cpu];
@@ -1498,7 +1506,7 @@ void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu)
 {
         struct ring_buffer_per_cpu *cpu_buffer;
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 return;
 
         cpu_buffer = buffer->buffers[cpu];
@@ -1515,7 +1523,7 @@ unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)
 {
         struct ring_buffer_per_cpu *cpu_buffer;
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 return 0;
 
         cpu_buffer = buffer->buffers[cpu];
@@ -1532,7 +1540,7 @@ unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu)
 {
         struct ring_buffer_per_cpu *cpu_buffer;
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 return 0;
 
         cpu_buffer = buffer->buffers[cpu];
@@ -1850,7 +1858,7 @@ rb_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
         struct buffer_page *reader;
         int nr_loops = 0;
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 return NULL;
 
         cpu_buffer = buffer->buffers[cpu];
@@ -2025,7 +2033,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts)
         struct ring_buffer_event *event;
         unsigned long flags;
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 return NULL;
 
         spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
@@ -2062,7 +2070,7 @@ ring_buffer_read_start(struct ring_buffer *buffer, int cpu)
         struct ring_buffer_iter *iter;
         unsigned long flags;
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 return NULL;
 
         iter = kmalloc(sizeof(*iter), GFP_KERNEL);
@@ -2172,7 +2180,7 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
         struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
         unsigned long flags;
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 return;
 
         spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
@@ -2228,7 +2236,7 @@ int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
 {
         struct ring_buffer_per_cpu *cpu_buffer;
 
-        if (!cpu_isset(cpu, buffer->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer->cpumask))
                 return 1;
 
         cpu_buffer = buffer->buffers[cpu];
@@ -2252,8 +2260,8 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
         struct ring_buffer_per_cpu *cpu_buffer_a;
         struct ring_buffer_per_cpu *cpu_buffer_b;
 
-        if (!cpu_isset(cpu, buffer_a->cpumask) ||
-            !cpu_isset(cpu, buffer_b->cpumask))
+        if (!cpumask_test_cpu(cpu, buffer_a->cpumask) ||
+            !cpumask_test_cpu(cpu, buffer_b->cpumask))
                 return -EINVAL;
 
         /* At least make sure the two buffers are somewhat the same */