linux-kernel - [RFC PATCH 1/2] sched/rt: Disable runtime accounting for idle threads with SCHED

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240410045417.3048209-2-quic_atulpant@quicinc.com>
Date: Wed, 10 Apr 2024 10:24:16 +0530
From: Atul Pant <quic_atulpant@...cinc.com>
To: mingo@...hat.com, peterz@...radead.org, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, dietmar.eggemann@....com,
        rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
        bristot@...hat.com, vschneid@...hat.com, rafael@...nel.org,
        daniel.lezcano@...aro.org
Cc: Atul Pant <quic_atulpant@...cinc.com>, kernel@...cinc.com,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org
Subject: [RFC PATCH 1/2] sched/rt: Disable runtime accounting for idle threads with SCHED_FIFO policy

To prevent the throttling of RT idle threads, like the idle-inject
threads, skip accounting of runtime for these threads.

Signed-off-by: Atul Pant <quic_atulpant@...cinc.com>
---
 kernel/sched/rt.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 4ac36eb4cdee..d20999270e75 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1075,7 +1075,9 @@ static void update_curr_rt(struct rq *rq)
 		struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
 		int exceeded;
 
-		if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
+		if (sched_rt_runtime(rt_rq) != RUNTIME_INF &&
+				!(curr->policy == SCHED_FIFO &&
+					curr->flags & PF_IDLE)) {
 			raw_spin_lock(&rt_rq->rt_runtime_lock);
 			rt_rq->rt_time += delta_exec;
 			exceeded = sched_rt_runtime_exceeded(rt_rq);
-- 
2.25.1