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Date:   Tue, 3 Mar 2020 19:33:29 -0800
From:   Matthew Wilcox <willy@infradead.org>
To:     Qian Cai <cai@lca.pw>
Cc:     paulmck@kernel.org, elver@google.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH -next] lib: disable KCSAN for XArray
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On Tue, Mar 03, 2020 at 10:15:51PM -0500, Qian Cai wrote:
> Functions like xas_find_marked(), xas_set_mark(), and xas_clear_mark()
> could happen concurrently result in data races, but those operate only
> on a single bit that are pretty much harmless. For example,

Those aren't data races.  The writes are protected by a spinlock and the
reads by the RCU read lock.  If the tool can't handle RCU protection,
it's not going to be much use.