From accddc41b96915ab4e5d37796c6d17d70805999c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@linutronix.de> Date: Wed, 10 Apr 2019 12:28:08 +0200 Subject: [PATCH] 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: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter 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 --- fs/proc/base.c | 3 +-- kernel/latencytop.c | 12 ++++++------ 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 6a803a0b75df..5569f215fc54 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -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'); diff --git a/kernel/latencytop.c b/kernel/latencytop.c index 96b4179cee6a..f5a90ab3c6b9 100644 --- a/kernel/latencytop.c +++ b/kernel/latencytop.c @@ -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"); -- GitLab