[for-next][PATCH 0/4] tracing: More updates for 5.13

[for-next][PATCH 0/4] tracing: More updates for 5.13

[Steven Rostedt]

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
for-next

Head SHA1: ceaaa12904df07d07ea8975abbf04c4d60e46956


Linus Torvalds (1):
      ftrace: Store the order of pages allocated in ftrace_page

Steven Rostedt (VMware) (1):
      ftrace: Simplify the calculation of page number for ftrace_page->records some more

Wan Jiabing (1):
      tracing: Remove duplicate struct declaration in trace_events.h

Yordan Karadzhov (VMware) (1):
      tracing: Remove unused argument from "ring_buffer_time_stamp()

----
 include/linux/ring_buffer.h  |  2 +-
 include/linux/trace_events.h |  1 -
 kernel/trace/ftrace.c        | 45 +++++++++++++++++++-------------------------
 kernel/trace/ring_buffer.c   |  2 +-
 kernel/trace/trace.c         |  8 ++++----
 5 files changed, 25 insertions(+), 33 deletions(-)

[for-next][PATCH 1/4] tracing: Remove duplicate struct declaration in trace_events.h

[Steven Rostedt]

From: Wan Jiabing <wanjiabing@vivo.com>

struct trace_array is declared twice. One has been declared
at forward declaration. Remove the duplicate.

Link: https://lkml.kernel.org/r/20210330034056.2266969-1-wanjiabing@vivo.com

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/trace_events.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 36e27c1f42e0..ad413b382a3c 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -404,7 +404,6 @@ trace_get_fields(struct trace_event_call *event_call)
 	return event_call->class->get_fields(event_call);
 }
 
-struct trace_array;
 struct trace_subsystem_dir;
 
 enum {
-- 
2.30.1

[for-next][PATCH 2/4] tracing: Remove unused argument from "ring_buffer_time_stamp()

[Steven Rostedt]

From: "Yordan Karadzhov (VMware)" <y.karadz@gmail.com>

The "cpu" parameter is not being used by the function.

Link: https://lkml.kernel.org/r/20210329130331.199402-1-y.karadz@gmail.com

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/ring_buffer.h | 2 +-
 kernel/trace/ring_buffer.c  | 2 +-
 kernel/trace/trace.c        | 8 ++++----
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 057b7ed4fe24..dac53fd3afea 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -181,7 +181,7 @@ unsigned long ring_buffer_commit_overrun_cpu(struct trace_buffer *buffer, int cp
 unsigned long ring_buffer_dropped_events_cpu(struct trace_buffer *buffer, int cpu);
 unsigned long ring_buffer_read_events_cpu(struct trace_buffer *buffer, int cpu);
 
-u64 ring_buffer_time_stamp(struct trace_buffer *buffer, int cpu);
+u64 ring_buffer_time_stamp(struct trace_buffer *buffer);
 void ring_buffer_normalize_time_stamp(struct trace_buffer *buffer,
 				      int cpu, u64 *ts);
 void ring_buffer_set_clock(struct trace_buffer *buffer,
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f4216df58e31..2c0ee6484990 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1080,7 +1080,7 @@ static inline u64 rb_time_stamp(struct trace_buffer *buffer)
 	return ts << DEBUG_SHIFT;
 }
 
-u64 ring_buffer_time_stamp(struct trace_buffer *buffer, int cpu)
+u64 ring_buffer_time_stamp(struct trace_buffer *buffer)
 {
 	u64 time;
 
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3834de91fb97..507a30bf26e4 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -771,7 +771,7 @@ static u64 buffer_ftrace_now(struct array_buffer *buf, int cpu)
 	if (!buf->buffer)
 		return trace_clock_local();
 
-	ts = ring_buffer_time_stamp(buf->buffer, cpu);
+	ts = ring_buffer_time_stamp(buf->buffer);
 	ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts);
 
 	return ts;
@@ -7174,7 +7174,7 @@ static int tracing_time_stamp_mode_open(struct inode *inode, struct file *file)
 u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe)
 {
 	if (rbe == this_cpu_read(trace_buffered_event))
-		return ring_buffer_time_stamp(buffer, smp_processor_id());
+		return ring_buffer_time_stamp(buffer);
 
 	return ring_buffer_event_time_stamp(buffer, rbe);
 }
@@ -8088,7 +8088,7 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 		trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n",
 								t, usec_rem);
 
-		t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu));
+		t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer));
 		usec_rem = do_div(t, USEC_PER_SEC);
 		trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem);
 	} else {
@@ -8097,7 +8097,7 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 				ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));
 
 		trace_seq_printf(s, "now ts: %llu\n",
-				ring_buffer_time_stamp(trace_buf->buffer, cpu));
+				ring_buffer_time_stamp(trace_buf->buffer));
 	}
 
 	cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu);
-- 
2.30.1

[for-next][PATCH 3/4] ftrace: Store the order of pages allocated in ftrace_page

[Steven Rostedt]

From: Linus Torvalds <torvalds@linux-foundation.org>

Instead of saving the size of the records field of the ftrace_page, store
the order it uses to allocate the pages, as that is what is needed to know
in order to free the pages. This simplifies the code.

Link: https://lore.kernel.org/lkml/CAHk-=whyMxheOqXAORt9a7JK9gc9eHTgCJ55Pgs4p=X3RrQubQ@mail.gmail.com/

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ change log written by Steven Rostedt ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 35 +++++++++++++++++------------------
 1 file changed, 17 insertions(+), 18 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 22ecaaa13baa..f7bef5a9ada9 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1090,7 +1090,7 @@ struct ftrace_page {
 	struct ftrace_page	*next;
 	struct dyn_ftrace	*records;
 	int			index;
-	int			size;
+	int			order;
 };
 
 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
@@ -3181,7 +3181,7 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count)
 	ftrace_number_of_groups++;
 
 	cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
-	pg->size = cnt;
+	pg->order = order;
 
 	if (cnt > count)
 		cnt = count;
@@ -3194,7 +3194,6 @@ ftrace_allocate_pages(unsigned long num_to_init)
 {
 	struct ftrace_page *start_pg;
 	struct ftrace_page *pg;
-	int order;
 	int cnt;
 
 	if (!num_to_init)
@@ -3230,13 +3229,13 @@ ftrace_allocate_pages(unsigned long num_to_init)
  free_pages:
 	pg = start_pg;
 	while (pg) {
-		order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-		if (order >= 0)
-			free_pages((unsigned long)pg->records, order);
+		if (pg->records) {
+			free_pages((unsigned long)pg->records, pg->order);
+			ftrace_number_of_pages -= 1 << pg->order;
+		}
 		start_pg = pg->next;
 		kfree(pg);
 		pg = start_pg;
-		ftrace_number_of_pages -= 1 << order;
 		ftrace_number_of_groups--;
 	}
 	pr_info("ftrace: FAILED to allocate memory for functions\n");
@@ -6188,6 +6187,7 @@ static int ftrace_process_locs(struct module *mod,
 	p = start;
 	pg = start_pg;
 	while (p < end) {
+		unsigned long end_offset;
 		addr = ftrace_call_adjust(*p++);
 		/*
 		 * Some architecture linkers will pad between
@@ -6198,7 +6198,8 @@ static int ftrace_process_locs(struct module *mod,
 		if (!addr)
 			continue;
 
-		if (pg->index == pg->size) {
+		end_offset = (pg->index+1) * sizeof(pg->records[0]);
+		if (end_offset > PAGE_SIZE << pg->order) {
 			/* We should have allocated enough */
 			if (WARN_ON(!pg->next))
 				break;
@@ -6367,7 +6368,6 @@ void ftrace_release_mod(struct module *mod)
 	struct ftrace_page **last_pg;
 	struct ftrace_page *tmp_page = NULL;
 	struct ftrace_page *pg;
-	int order;
 
 	mutex_lock(&ftrace_lock);
 
@@ -6418,12 +6418,12 @@ void ftrace_release_mod(struct module *mod)
 		/* Needs to be called outside of ftrace_lock */
 		clear_mod_from_hashes(pg);
 
-		order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-		if (order >= 0)
-			free_pages((unsigned long)pg->records, order);
+		if (pg->records) {
+			free_pages((unsigned long)pg->records, pg->order);
+			ftrace_number_of_pages -= 1 << pg->order;
+		}
 		tmp_page = pg->next;
 		kfree(pg);
-		ftrace_number_of_pages -= 1 << order;
 		ftrace_number_of_groups--;
 	}
 }
@@ -6741,7 +6741,6 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
 	struct ftrace_mod_map *mod_map = NULL;
 	struct ftrace_init_func *func, *func_next;
 	struct list_head clear_hash;
-	int order;
 
 	INIT_LIST_HEAD(&clear_hash);
 
@@ -6779,10 +6778,10 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
 		ftrace_update_tot_cnt--;
 		if (!pg->index) {
 			*last_pg = pg->next;
-			order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-			if (order >= 0)
-				free_pages((unsigned long)pg->records, order);
-			ftrace_number_of_pages -= 1 << order;
+			if (pg->records) {
+				free_pages((unsigned long)pg->records, pg->order);
+				ftrace_number_of_pages -= 1 << pg->order;
+			}
 			ftrace_number_of_groups--;
 			kfree(pg);
 			pg = container_of(last_pg, struct ftrace_page, next);
-- 
2.30.1

[for-next][PATCH 4/4] ftrace: Simplify the calculation of page number for ftrace_page->records some more

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

Commit b40c6eabfcd40 ("ftrace: Simplify the calculation of page number for
ftrace_page->records") simplified the calculation of the number of pages
needed for each page group without having any empty pages, but it can be
simplified even further.

Link: https://lore.kernel.org/lkml/CAHk-=wjt9b7kxQ2J=aDNKbR1QBMB3Hiqb_hYcZbKsxGRSEb+gQ@mail.gmail.com/

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f7bef5a9ada9..057e962ca5ce 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3156,15 +3156,9 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count)
 	if (WARN_ON(!count))
 		return -EINVAL;
 
+	/* We want to fill as much as possible, with no empty pages */
 	pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE);
-	order = get_count_order(pages);
-
-	/*
-	 * We want to fill as much as possible. No more than a page
-	 * may be empty.
-	 */
-	if (!is_power_of_2(pages))
-		order--;
+	order = fls(pages) - 1;
 
  again:
 	pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
-- 
2.30.1