From: Peter Zijlstra <peterz@infradead.org>
To: Waiman Long <longman@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org,
Yang Shi <yang.shi@linux.alibaba.com>,
Arnd Bergmann <arnd@arndb.de>,
chuhu@redhat.com
Subject: Re: [PATCH v2 2/2] debugobjects: Disable lockdep tracking of debugobjects internal locks
Date: Tue, 25 Sep 2018 17:32:41 +0200 [thread overview]
Message-ID: <20180925153241.GD29985@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1537886469-18227-3-git-send-email-longman@redhat.com>
On Tue, Sep 25, 2018 at 10:41:09AM -0400, Waiman Long wrote:
> diff --git a/lib/debugobjects.c b/lib/debugobjects.c
> index 70935ed91125..68d72ed9ca22 100644
> --- a/lib/debugobjects.c
> +++ b/lib/debugobjects.c
> @@ -1106,8 +1106,15 @@ void __init debug_objects_early_init(void)
> {
> int i;
>
> - for (i = 0; i < ODEBUG_HASH_SIZE; i++)
> + /*
> + * We don't need lockdep to verify correctness of debugobjects
> + * internal locks.
> + */
> + lockdep_set_novalidate_class(&pool_lock);
> + for (i = 0; i < ODEBUG_HASH_SIZE; i++) {
> raw_spin_lock_init(&obj_hash[i].lock);
> + lockdep_set_novalidate_class(&obj_hash[i].lock);
> + }
>
> for (i = 0; i < ODEBUG_POOL_SIZE; i++)
> hlist_add_head(&obj_static_pool[i].node, &obj_pool);
NAK, we do not _EVER_ set novalidate if it can at all be avoided.
If there is a severe performance problem with lockdep, try and cure
that. But really, who runs lockdep kernels on 8 sockets?
next prev parent reply other threads:[~2018-09-25 15:33 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-25 14:41 [PATCH v2 0/2] debugobjects: Fix potential hard lockup by disabling lockdep Waiman Long
2018-09-25 14:41 ` [PATCH v2 1/2] locking/lockdep: Don't warn class/lock name mismatch for novalidate class Waiman Long
2018-09-25 14:41 ` [PATCH v2 2/2] debugobjects: Disable lockdep tracking of debugobjects internal locks Waiman Long
2018-09-25 15:32 ` Peter Zijlstra [this message]
2018-09-25 16:20 ` Waiman Long
2018-09-25 16:31 ` Peter Zijlstra
2018-09-25 16:36 ` Waiman Long
2018-09-28 18:33 ` Waiman Long
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