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Date:   Wed, 13 Feb 2019 12:26:15 -0800
From:   Matthew Wilcox <willy@infradead.org>
To:     Roman Gushchin <guro@fb.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Roman Gushchin <guroan@gmail.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        Kernel Team <Kernel-team@fb.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 0/3] vmalloc enhancements
Message-ID: <20190213202614.GV12668@bombadil.infradead.org>
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 <20190212184724.GA18339@cmpxchg.org>
 <20190212123409.7ed5c34d68466dbd8b7013a3@linux-foundation.org>
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On Tue, Feb 12, 2019 at 10:36:12PM +0000, Roman Gushchin wrote:
> On Tue, Feb 12, 2019 at 12:34:09PM -0800, Andrew Morton wrote:
> > On Tue, 12 Feb 2019 13:47:24 -0500 Johannes Weiner <hannes@cmpxchg.org> wrote:
> > > I don't understand what prompted this change to percpu counters.
> 
> I *think*, I see some performance difference, but it's barely measurable
> in my setup. Also as I remember, Matthew was asking why not percpu here.
> So if everybody prefers a global atomic, I'm fine with either.

I was asking why you were using an accessor instead of a direct reference
to the atomic_long_t.