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From:   Waiman Long <longman@redhat.com>
To:     Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>
Cc:     cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com,
        luto@amacapital.net, Mike Galbraith <efault@gmx.de>,
        torvalds@linux-foundation.org, Roman Gushchin <guro@fb.com>,
        Juri Lelli <juri.lelli@redhat.com>,
        Waiman Long <longman@redhat.com>
Subject: [PATCH v8 6/6] cpuset: Allow reporting of sched domain generation info
Date:   Thu, 17 May 2018 16:55:45 -0400
Message-Id: <1526590545-3350-7-git-send-email-longman@redhat.com>
In-Reply-To: <1526590545-3350-1-git-send-email-longman@redhat.com>
References: <1526590545-3350-1-git-send-email-longman@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

This patch enables us to report sched domain generation information.

If DYNAMIC_DEBUG is enabled, issuing the following command

  echo "file cpuset.c +p" > /sys/kernel/debug/dynamic_debug/control

and setting loglevel to 8 will allow the kernel to show what scheduling
domain changes are being made.

Signed-off-by: Waiman Long <longman@redhat.com>
---
 kernel/cgroup/cpuset.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index fb8aa82b..8f586e8 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -820,6 +820,12 @@ static int generate_sched_domains(cpumask_var_t **domains,
 	}
 	BUG_ON(nslot != ndoms);
 
+#ifdef CONFIG_DEBUG_KERNEL
+	for (i = 0; i < ndoms; i++)
+		pr_debug("generate_sched_domains dom %d: %*pbl\n", i,
+			 cpumask_pr_args(doms[i]));
+#endif
+
 done:
 	kfree(csa);
 
-- 
1.8.3.1