54 lines
2.2 KiB
Diff
54 lines
2.2 KiB
Diff
From 44cbc6f537c24d27d6e1b7544ac5138fa6707e1c Mon Sep 17 00:00:00 2001
|
|
Message-Id: <44cbc6f537c24d27d6e1b7544ac5138fa6707e1c.1596234184.git.zanussi@kernel.org>
|
|
In-Reply-To: <378ee68279f6a7631221f2670a9298620148690d.1596234183.git.zanussi@kernel.org>
|
|
References: <378ee68279f6a7631221f2670a9298620148690d.1596234183.git.zanussi@kernel.org>
|
|
From: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
|
|
Date: Tue, 28 Apr 2020 16:40:26 +0200
|
|
Subject: [PATCH 325/329] hrtimer: fix logic for when grabbing
|
|
softirq_expiry_lock can be elided
|
|
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.135-rt60.tar.xz
|
|
|
|
Commit
|
|
|
|
hrtimer: Add a missing bracket and hide `migration_base' on !SMP
|
|
|
|
which is 47b6de0b7f22 in 5.2-rt and 40aae5708e7a in 4.19-rt,
|
|
inadvertently changed the logic from base != &migration_base to base
|
|
== &migration_base.
|
|
|
|
On !CONFIG_SMP, the effect was to effectively always elide this
|
|
lock/unlock pair (since is_migration_base() is unconditionally false),
|
|
which for me consistently causes lockups during reboot, and reportedly
|
|
also often causes a hang during boot.
|
|
|
|
Adding this logical negation (or, what is effectively the same thing
|
|
on !CONFIG_SMP, reverting the above commit as well as "hrtimer:
|
|
Prevent using hrtimer_grab_expiry_lock() on migration_base") fixes
|
|
that lockup.
|
|
|
|
Fixes: 40aae5708e7a (hrtimer: Add a missing bracket and hide `migration_base' on !SMP) # 4.19-rt
|
|
Fixes: 47b6de0b7f22 (hrtimer: Add a missing bracket and hide `migration_base' on !SMP) # 5.2-rt
|
|
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
|
|
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
|
|
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
|
|
---
|
|
kernel/time/hrtimer.c | 2 +-
|
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
|
|
|
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
|
|
index e54a95de8b79..c3966c090246 100644
|
|
--- a/kernel/time/hrtimer.c
|
|
+++ b/kernel/time/hrtimer.c
|
|
@@ -953,7 +953,7 @@ void hrtimer_grab_expiry_lock(const struct hrtimer *timer)
|
|
{
|
|
struct hrtimer_clock_base *base = READ_ONCE(timer->base);
|
|
|
|
- if (timer->is_soft && is_migration_base(base)) {
|
|
+ if (timer->is_soft && !is_migration_base(base)) {
|
|
spin_lock(&base->cpu_base->softirq_expiry_lock);
|
|
spin_unlock(&base->cpu_base->softirq_expiry_lock);
|
|
}
|
|
--
|
|
2.17.1
|
|
|