From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH AUTOSEL 4.14 21/25] powerpc/pseries: Stop calling printk in rtas_stop_self()
Date: Wed, 5 May 2021 12:40:47 -0400 [thread overview]
Message-ID: <20210505164051.3464020-21-sashal@kernel.org> (raw)
In-Reply-To: <20210505164051.3464020-1-sashal@kernel.org>
From: Michael Ellerman <mpe@ellerman.id.au>
[ Upstream commit ed8029d7b472369a010a1901358567ca3b6dbb0d ]
RCU complains about us calling printk() from an offline CPU:
=============================
WARNING: suspicious RCU usage
5.12.0-rc7-02874-g7cf90e481cb8 #1 Not tainted
-----------------------------
kernel/locking/lockdep.c:3568 RCU-list traversed in non-reader section!!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 2, debug_locks = 1
no locks held by swapper/0/0.
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7-02874-g7cf90e481cb8 #1
Call Trace:
dump_stack+0xec/0x144 (unreliable)
lockdep_rcu_suspicious+0x124/0x144
__lock_acquire+0x1098/0x28b0
lock_acquire+0x128/0x600
_raw_spin_lock_irqsave+0x6c/0xc0
down_trylock+0x2c/0x70
__down_trylock_console_sem+0x60/0x140
vprintk_emit+0x1a8/0x4b0
vprintk_func+0xcc/0x200
printk+0x40/0x54
pseries_cpu_offline_self+0xc0/0x120
arch_cpu_idle_dead+0x54/0x70
do_idle+0x174/0x4a0
cpu_startup_entry+0x38/0x40
rest_init+0x268/0x388
start_kernel+0x748/0x790
start_here_common+0x1c/0x614
Which happens because by the time we get to rtas_stop_self() we are
already offline. In addition the message can be spammy, and is not that
helpful for users, so remove it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210418135413.1204031-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/platforms/pseries/hotplug-cpu.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 0baaaa6b0929..73071c4339c5 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -95,9 +95,6 @@ static void rtas_stop_self(void)
BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE);
- printk("cpu %u (hwid %u) Ready to die...\n",
- smp_processor_id(), hard_smp_processor_id());
-
rtas_call_unlocked(&args, rtas_stop_self_token, 0, 1, NULL);
panic("Alas, I survived.\n");
--
2.30.2
next prev parent reply other threads:[~2021-05-05 16:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210505164051.3464020-1-sashal@kernel.org>
2021-05-05 16:40 ` [PATCH AUTOSEL 4.14 18/25] powerpc/smp: Set numa node before updating mask Sasha Levin
2021-05-05 16:40 ` Sasha Levin [this message]
2021-05-05 16:40 ` [PATCH AUTOSEL 4.14 24/25] powerpc/iommu: Annotate nested lock for lockdep Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210505164051.3464020-21-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).