Red Hat Bugzilla – Bug 1490673
Kernel Panic always happen immediately whenever make "debug.panic_on_rcu_stall=1" set on RHEL7.4
Last modified: 2018-04-10 18:04:24 EDT
Description of problem: Kernel Panic always happen immediately whenever make "debug.panic_on_rcu_stall=1" set on RHEL7.4 Version-Release number of selected component (if applicable): Kernel-3.10.0-693.el7 on RHEL7.4(GA) or later How reproducible: 100% Steps to Reproduce: 1. # uname -r 3.10.0-693.1.1.el7.x86_64 2. # cat /proc/sys/debug/panic_on_rcu_stall 0 3. # echo 1 > /proc/sys/debug/panic_on_rcu_stall Actual results: kernel panic always happen. Expected results: When set to 1, calls panic() after RCU stall detection messages When Additional info:
Created attachment 1324651 [details] vmcore-dmesg.txt
It looks like RHEL commit 6cbfcf1526c74681ac81cda667f6f89016b47b8f backported upstream commit wrongly. We should have following diff on top of current RHEL7 code to backport upstream commit 088e9d253d3a4ab7e058dd84bb532c32dadf1882 correctly. -------------------><-------------- diff --git a/kernel/rcutree.c b/kernel/rcutree.c index f46e3e44c0af..981fb8baf895 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1000,6 +1000,8 @@ static void print_cpu_stall(struct rcu_state *rsp) 3 * rcu_jiffies_till_stall_check() + 3; raw_spin_unlock_irqrestore(&rnp->lock, flags); + panic_on_rcu_stall(); + set_need_resched(); /* kick ourselves to get things going. */ } @@ -1016,8 +1018,6 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) return; j = ACCESS_ONCE(jiffies); - panic_on_rcu_stall(); - /* * Lots of memory barriers to reject false positives. * -------------------><-------------- I will prepare a brew build with above diff, I hope that should resolve it.
Hi all this is private account test.Please ignore it.
Patch(es) committed on kernel repository and an interim kernel build is undergoing testing
Patch(es) available on kernel-3.10.0-720.el7
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2018:1062