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Date:   Fri, 9 Feb 2018 06:07:28 -0800
From:   Matthew Wilcox <willy@infradead.org>
To:     Kai Heng Feng <kai.heng.feng@canonical.com>
Cc:     Michal Hocko <mhocko@suse.com>, Laura Abbott <labbott@redhat.com>,
        linux-mm@kvack.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Regression after commit 19809c2da28a ("mm, vmalloc: use
 __GFP_HIGHMEM implicitly")
Message-ID: <20180209140728.GC16666@bombadil.infradead.org>
References: <627DA40A-D0F6-41C1-BB5A-55830FBC9800@canonical.com>
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 <20180208232004.GA21027@bombadil.infradead.org>
 <20180209040814.GA23828@bombadil.infradead.org>
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On Fri, Feb 09, 2018 at 05:12:56PM +0800, Kai Heng Feng wrote:
> Hi Matthew,
> 
> > On Feb 9, 2018, at 12:08 PM, Matthew Wilcox <willy@infradead.org> wrote:
> > Alternatively, try this.  It passes in GFP_DMA32 from vmalloc_32,
> > regardless of whether ZONE_DMA32 exists or not.  If ZONE_DMA32 doesn't
> > exist, then we clear it in __vmalloc_area_node(), after using it to
> > determine that we shouldn't set __GFP_HIGHMEM.
> 
> IIUC, I need to let drivers/media drivers start using vmalloc_32() with your
> patch, right?

Hopefully those that need to already are.  Otherwise they're broken
on 64-bit.  I do see several places already using vmalloc_32().