linux-kernel - [patch V2 35/38] posix-cpu-timers: Remove pointless comparisons

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Message-Id: <20190821192922.548747613@linutronix.de>
Date:   Wed, 21 Aug 2019 21:09:22 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     Oleg Nesterov <oleg@...hat.com>, Ingo Molnar <mingo@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        John Stultz <john.stultz@...aro.org>,
        Frederic Weisbecker <frederic@...nel.org>,
        Anna-Maria Behnsen <anna-maria@...utronix.de>,
        Christoph Hellwig <hch@....de>
Subject: [patch V2 35/38] posix-cpu-timers: Remove pointless comparisons

The soft RLIMIT expiry code checks whether the soft limit is greater than
the hard limit. That's pointless because if the soft RLIMIT is greater than
the hard RLIMIT then that code cannot be reached as the hard RLIMIT check
is before that and already killed the process.

Remove it.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
V2: Fixup vs. the previous patch changes
---
 kernel/time/posix-cpu-timers.c |   16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -814,15 +814,14 @@ static void check_thread_timers(struct t
 			__group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
 			return;
 		}
+
 		if (rtim >= soft) {
 			/*
 			 * At the soft limit, send a SIGXCPU every second.
 			 */
-			if (soft < hard) {
-				soft += USEC_PER_SEC;
-				tsk->signal->rlim[RLIMIT_RTTIME].rlim_cur =
-					soft;
-			}
+			soft += USEC_PER_SEC;
+			tsk->signal->rlim[RLIMIT_RTTIME].rlim_cur = soft;
+
 			if (print_fatal_signals) {
 				pr_info("RT Watchdog Timeout (soft): %s[%d]\n",
 					tsk->comm, task_pid_nr(tsk));
@@ -938,10 +937,9 @@ static void check_process_timers(struct
 					tsk->comm, task_pid_nr(tsk));
 			}
 			__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
-			if (soft < hard) {
-				sig->rlim[RLIMIT_CPU].rlim_cur = soft + 1;
-				softns += NSEC_PER_SEC;
-			}
+
+			sig->rlim[RLIMIT_CPU].rlim_cur = soft + 1;
+			softns += NSEC_PER_SEC;
 		}
 
 		/* Update the expiry cache */