Commit accddc41 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

latency_top: Remove the ULONG_MAX stack trace hackery 



No architecture terminates the stack trace with ULONG_MAX anymore. The
consumer terminates on the first zero entry or at the number of entries, so
no functional change.

Remove the cruft.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Link: https://lkml.kernel.org/r/20190410103644.853527514@linutronix.de
parent ead97a49

fs/proc/base.c

+1 −2
Original line number Diff line number Diff line
@@ -489,10 +489,9 @@ static int lstats_show_proc(struct seq_file *m, void *v) 
				   lr->count, lr->time, lr->max);

			for (q = 0; q < LT_BACKTRACEDEPTH; q++) {

				unsigned long bt = lr->backtrace[q];



				if (!bt)

					break;

				if (bt == ULONG_MAX)

					break;

				seq_printf(m, " %ps", (void *)bt);

			}

			seq_putc(m, '\n');

kernel/latencytop.c

+6 −6
Original line number Diff line number Diff line
@@ -120,8 +120,8 @@ account_global_scheduler_latency(struct task_struct *tsk, 
				break;

			}



			/* 0 and ULONG_MAX entries mean end of backtrace: */

			if (record == 0 || record == ULONG_MAX)

			/* 0 entry marks end of backtrace: */

			if (!record)

				break;

		}

		if (same) {
@@ -210,8 +210,8 @@ __account_scheduler_latency(struct task_struct *tsk, int usecs, int inter) 
				break;

			}



			/* 0 and ULONG_MAX entries mean end of backtrace: */

			if (record == 0 || record == ULONG_MAX)

			/* 0 entry is end of backtrace */

			if (!record)

				break;

		}

		if (same) {
@@ -252,10 +252,10 @@ static int lstats_show(struct seq_file *m, void *v) 
				   lr->count, lr->time, lr->max);

			for (q = 0; q < LT_BACKTRACEDEPTH; q++) {

				unsigned long bt = lr->backtrace[q];



				if (!bt)

					break;

				if (bt == ULONG_MAX)

					break;



				seq_printf(m, " %ps", (void *)bt);

			}

			seq_puts(m, "\n");

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