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Commit f21f7fa2 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

Merge tag 'trace-v4.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Steven writes:
  "Vaibhav Nagarnaik found that modifying the ring buffer size could cause
   a huge latency in the system because it does a while loop to free pages
   without releasing the CPU (on non preempt kernels). In a case where there
   are hundreds of thousands of pages to free it could actually cause a system
   stall. A properly place cond_resched() solves this issue."
parents eba2d6b3 83f36555

kernel/trace/ring_buffer.c

+2 −0
Original line number Diff line number Diff line
@@ -1546,6 +1546,8 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned long nr_pages) 
	tmp_iter_page = first_page;



	do {

		cond_resched();



		to_remove_page = tmp_iter_page;

		rb_inc_page(cpu_buffer, &tmp_iter_page);