Commit c09d4167 authored by Vincent Donnefort's avatar Vincent Donnefort Committed by Steven Rostedt (Google)
Browse files

ring-buffer: Allocate sub-buffers with __GFP_COMP 

In preparation for the ring-buffer memory mapping, allocate compound
pages for the ring-buffer sub-buffers to enable us to map them to
user-space with vm_insert_pages().

Link: https://lore.kernel.org/linux-trace-kernel/20240510140435.3550353-2-vdonnefort@google.com



Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarVincent Donnefort <vdonnefort@google.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent dd5a440a

kernel/trace/ring_buffer.c

+3 −3
Original line number Diff line number Diff line
@@ -1524,7 +1524,7 @@ static int __rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, 
		list_add(&bpage->list, pages);



		page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu),

					mflags | __GFP_ZERO,

					mflags | __GFP_COMP | __GFP_ZERO,

					cpu_buffer->buffer->subbuf_order);

		if (!page)

			goto free_pages;
@@ -1609,7 +1609,7 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu) 


	cpu_buffer->reader_page = bpage;



	page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL | __GFP_ZERO,

	page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL | __GFP_COMP | __GFP_ZERO,

				cpu_buffer->buffer->subbuf_order);

	if (!page)

		goto fail_free_reader;
@@ -5579,7 +5579,7 @@ ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu) 
		goto out;



	page = alloc_pages_node(cpu_to_node(cpu),

				GFP_KERNEL | __GFP_NORETRY | __GFP_ZERO,

				GFP_KERNEL | __GFP_NORETRY | __GFP_COMP | __GFP_ZERO,

				cpu_buffer->buffer->subbuf_order);

	if (!page) {

		kfree(bpage);