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Date:   Mon, 30 Sep 2019 10:06:13 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Vlastimil Babka <vbabka@suse.cz>
Cc:     Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Ming Lei <ming.lei@redhat.com>,
        Dave Chinner <david@fromorbit.com>,
        Matthew Wilcox <willy@infradead.org>,
        "Darrick J . Wong" <darrick.wong@oracle.com>,
        Christoph Hellwig <hch@lst.de>, linux-xfs@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        James Bottomley <James.Bottomley@HansenPartnership.com>,
        linux-btrfs@vger.kernel.org, Roman Gushchin <guro@fb.com>,
        Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH v2 2/2] mm, sl[aou]b: guarantee natural alignment for
 kmalloc(power-of-two)
Message-ID: <20190930080613.GA5379@lst.de>
References: <20190826111627.7505-1-vbabka@suse.cz> <20190826111627.7505-3-vbabka@suse.cz> <df8d1cf4-ff8f-1ee1-12fb-cfec39131b32@suse.cz>
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On Mon, Sep 23, 2019 at 06:36:32PM +0200, Vlastimil Babka wrote:
> So if anyone thinks this is a good idea, please express it (preferably
> in a formal way such as Acked-by), otherwise it seems the patch will be
> dropped (due to a private NACK, apparently).

I think we absolutely need something like this, and I'm sick and tired
of the people just claiming there is no problem.

From the user POV I don't care if aligned allocations need a new
GFP_ALIGNED flag or not, but as far as I can tell the latter will
probably cause more overhead in practice than not having it.

So unless someone comes up with a better counter proposal to provide
aligned kmalloc of some form that doesn't require a giant amount of
boilerplate code in the users:

Acked^2-by: Christoph Hellwig <hch@lst.de>