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From:   zhouzhouyi@gmail.com
To:     paulmck@kernel.org, rcu@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        lance@osuosl.org
Cc:     Zhouyi Zhou <zhouzhouyi@gmail.com>
Subject: [PATCH RFC] rcu: torture: shorten the time between forward-progress tests
Date:   Tue,  2 May 2023 23:06:02 +0800
Message-Id: <1683039962-15751-1-git-send-email-zhouzhouyi@gmail.com>
Precedence: bulk

From: Zhouyi Zhou <zhouzhouyi@gmail.com>

Currently, default time between rcu torture forward-progress tests is 60HZ,
Under this configuration, false positive caused by __stack_chk_fail [1] is
difficult to reproduce (needs average 5*420 seconds for SRCU-P),
which means one has to invoke [2] 5 times in average to make [1] appear.

With time between rcu torture forward-progress tests be 1 HZ, above
phenomenon will be reproduced within 3 minutes, which means we can
reproduce [1] everytime we invoke [2].

Although [1] is a false positive, this change will make possible future
true bugs easier to be discovered.            
                   
[1] Link: https://lore.kernel.org/lkml/CAABZP2yS5=ZUwEZQ7iHkV0wDm_HgO8K-TeAhyJrZhavzKDa44Q@mail.gmail.com/T/
[2] tools/testing/selftests/rcutorture/bin/torture.sh

Tested in PPC VM of Opensource Lab of Oregon State Univerisity.
        
Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>        
---
 tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot  | 1 +
 tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot  | 1 +
 tools/testing/selftests/rcutorture/configs/rcu/TRACE02.boot | 1 +
 tools/testing/selftests/rcutorture/configs/rcu/TREE02.boot  | 1 +
 tools/testing/selftests/rcutorture/configs/rcu/TREE10.boot  | 1 +
 5 files changed, 5 insertions(+)

diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot
index ce0694fd9b92..982582bff041 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot
@@ -1,2 +1,3 @@
 rcutorture.torture_type=srcu
 rcutorture.fwd_progress=3
+rcutorture.fwd_progress_holdoff=1
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot
index 2db39f298d18..18f5d7361d8a 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot
@@ -1,4 +1,5 @@
 rcutorture.torture_type=srcud
 rcupdate.rcu_self_test=1
 rcutorture.fwd_progress=3
+rcutorture.fwd_progress_holdoff=1
 srcutree.big_cpu_lim=5
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRACE02.boot b/tools/testing/selftests/rcutorture/configs/rcu/TRACE02.boot
index c70b5db6c2ae..b86bc7df7603 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TRACE02.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TRACE02.boot
@@ -1,2 +1,3 @@
 rcutorture.torture_type=tasks-tracing
 rcutorture.fwd_progress=2
+rcutorture.fwd_progress_holdoff=1
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE02.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE02.boot
index dd914fa8f690..933302f885df 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE02.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE02.boot
@@ -1 +1,2 @@
 rcutorture.fwd_progress=2
+rcutorture.fwd_progress_holdoff=1
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE10.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE10.boot
index dd914fa8f690..933302f885df 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE10.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE10.boot
@@ -1 +1,2 @@
 rcutorture.fwd_progress=2
+rcutorture.fwd_progress_holdoff=1
-- 
2.34.1