Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1595419

Re: RFC: SysRq nice-all-RT-tasks is broken

Path csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!news.unit0.net!news.panservice.it!bofh.it!news.nic.it!robomod
From Steven Rostedt <rostedt@goodmis.org>
Newsgroups linux.kernel
Subject Re: RFC: SysRq nice-all-RT-tasks is broken
Date Wed, 08 Mar 2017 19:00:01 +0100
Message-ID <tiO2t-1rn-3@gated-at.bofh.it> (permalink)
References <tiLHk-8qM-21@gated-at.bofh.it> <tiN6p-Q0-5@gated-at.bofh.it> <tiN6q-Q0-17@gated-at.bofh.it> <tiNSO-1nX-19@gated-at.bofh.it> <tiNSO-1nX-17@gated-at.bofh.it>
X-Original-To Laurent Dufour <ldufour@linux.vnet.ibm.com>
X-Mailer Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu)
MIME-Version 1.0
Content-Type text/plain; charset=US-ASCII
Content-Transfer-Encoding 7bit
Sender robomod@news.nic.it
List-ID <linux-kernel.vger.kernel.org>
X-Mailing-List linux-kernel@vger.kernel.org
Approved robomod@news.nic.it
Lines 28
Organization linux.* mail to news gateway
X-Original-Cc Andrew Morton <akpm@osdl.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>, Peter Zijlstra <peterz@infradead.org>
X-Original-Date Wed, 8 Mar 2017 12:46:54 -0500
X-Original-Message-ID <20170308124654.10e598f2@gandalf.local.home>
X-Original-References <be47a577-7dfe-a7b3-57e0-1f182edc568b@linux.vnet.ibm.com> <20170308115114.4e20fc73@gandalf.local.home> <20170308115758.43b38bc7@gandalf.local.home> <22b0e5fe-2aa1-72de-4d00-29d768d226ca@linux.vnet.ibm.com> <20170308124012.496a75cf@gandalf.local.home>
X-Original-Sender linux-kernel-owner@vger.kernel.org
Xref csiph.com linux.kernel:1595419

Show key headers only | View raw


On Wed, 8 Mar 2017 12:40:12 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> I wonder if we should just have a special flag sent by that sysrq
> trigger. Since it is causing all tasks to go "nice" there's no need to
> do the pi chain walk in __sched_setscheduler().

Hah, there already is a flag!

Laurent, can you test this patch:

-- Steve

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3b31fc0..7292fa9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4129,8 +4129,8 @@ static int __sched_setscheduler(struct task_struct *p,
 	int queue_flags = DEQUEUE_SAVE | DEQUEUE_MOVE;
 	struct rq *rq;
 
-	/* May grab non-irq protected spin_locks: */
-	BUG_ON(in_interrupt());
+	/* The pi code expects interrupts enabled */
+	BUG_ON(pi && in_interrupt());
 recheck:
 	/* Double check policy once rq lock held: */
 	if (policy < 0) {

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

RFC: SysRq nice-all-RT-tasks is broken Laurent Dufour <ldufour@linux.vnet.ibm.com> - 2017-03-08 16:30 +0100
  Re: RFC: SysRq nice-all-RT-tasks is broken Steven Rostedt <rostedt@goodmis.org> - 2017-03-08 18:00 +0100
    Re: RFC: SysRq nice-all-RT-tasks is broken Steven Rostedt <rostedt@goodmis.org> - 2017-03-08 18:00 +0100
      Re: RFC: SysRq nice-all-RT-tasks is broken Steven Rostedt <rostedt@goodmis.org> - 2017-03-08 18:50 +0100
        Re: RFC: SysRq nice-all-RT-tasks is broken Steven Rostedt <rostedt@goodmis.org> - 2017-03-08 19:00 +0100
          Re: RFC: SysRq nice-all-RT-tasks is broken Laurent Dufour <ldufour@linux.vnet.ibm.com> - 2017-03-09 12:30 +0100
      Re: RFC: SysRq nice-all-RT-tasks is broken Laurent Dufour <ldufour@linux.vnet.ibm.com> - 2017-03-08 22:10 +0100

csiph-web