Date:   Mon, 20 Mar 2023 08:40:40 +0000
From:   Lorenzo Stoakes <lstoakes@gmail.com>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        Baoquan He <bhe@redhat.com>,
        Uladzislau Rezki <urezki@gmail.com>,
        David Hildenbrand <david@redhat.com>,
        Liu Shixin <liushixin2@huawei.com>,
        Jiri Olsa <jolsa@kernel.org>
Subject: Re: [PATCH v2 2/4] mm: vmalloc: use rwsem, mutex for vmap_area_lock
 and vmap_block->lock
Message-ID: <ce89fe94-dc8d-4e10-9181-e01760939ef6@lucifer.local>
References: <cover.1679209395.git.lstoakes@gmail.com>
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 <fadd8558-8917-4012-b5ea-c6376c835cc8@lucifer.local>
 <ZBd00i7fvwrMX/FY@casper.infradead.org>
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On Sun, Mar 19, 2023 at 09:16:18PM +0000, Lorenzo Stoakes wrote:
> On Sun, Mar 19, 2023 at 08:47:14PM +0000, Matthew Wilcox wrote:
> > I wonder if we can't do something like prefaulting the page before
> > taking the spinlock, then use copy_page_to_iter_atomic()
>
<snip>

On second thoughts, and discussing with Uladzislau, this seems like a more
sensible approach.

I'm going to respin with prefaulting and revert to the previous locking.