Date:   Tue, 16 Nov 2021 11:27:38 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Minchan Kim <minchan@kernel.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        linux-mm <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 7/9] locking/rwlocks: introduce write_lock_nested
Message-ID: <YZOHmkdTM+oimFe8@hirez.programming.kicks-ass.net>
References: <20211115185909.3949505-1-minchan@kernel.org>
 <20211115185909.3949505-8-minchan@kernel.org>
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On Mon, Nov 15, 2021 at 10:59:07AM -0800, Minchan Kim wrote:
> In preparation for converting bit_spin_lock to rwlock in zsmalloc
> so that multiple writers of zspages can run at the same time but
> those zspages are supposed to be different zspage instance. Thus,
> it's not deadlock. This patch adds write_lock_nested to support
> the case for LOCKDEP.
> 
> Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
> Signed-off-by: Minchan Kim <minchan@kernel.org>
> ---
>  include/linux/rwlock.h          |  6 ++++++
>  include/linux/rwlock_api_smp.h  |  9 +++++++++
>  include/linux/rwlock_rt.h       |  6 ++++++
>  include/linux/spinlock_api_up.h |  1 +
>  kernel/locking/spinlock.c       |  6 ++++++
>  kernel/locking/spinlock_rt.c    | 12 ++++++++++++
>  6 files changed, 40 insertions(+)

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>