Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Sat, 15 Apr 2023 04:49:44 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     SeongJae Park <sj@kernel.org>
Cc:     akpm@linux-foundation.org, vbabka@suse.cz, paulmck@kernel.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] mm/slab: break up RCU readers on
 SLAB_TYPESAFE_BY_RCU example code
Message-ID: <ZDoe2K7mMu31/6Lb@casper.infradead.org>
References: <20230415033159.4249-1-sj@kernel.org>
 <20230415033159.4249-3-sj@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230415033159.4249-3-sj@kernel.org>
Precedence: bulk

On Sat, Apr 15, 2023 at 03:31:59AM +0000, SeongJae Park wrote:
> The SLAB_TYPESAFE_BY_RCU example code snippet is having not tiny RCU
> read-side critical section.  'Documentation/RCU/rculist_nulls.rst' has
> similar example code snippet, and commit da82af04352b ("doc: Update and
> wordsmith rculist_nulls.rst") has broken it.  Apply the change to
> SLAB_TYPESAFE_BY_RCU example code snippet, too.

so the page cache (eg find_get_entry()) does not follow this "split
the RCU critical section" pattern.  Should it?  What's the benefit?