Re: [PATCH] Revert "mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE"

From: Andrew Morton <akpm@linux-foundation.org>
To: Joonsoo Kim <js1304@gmail.com>
Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com>,
	"Laura Abbott" <labbott@redhat.com>,
	"Michal Hocko" <mhocko@kernel.org>,
	"Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>,
	"Tony Lindgren" <tony@atomide.com>,
	"Vlastimil Babka" <vbabka@suse.cz>,
	"Johannes Weiner" <hannes@cmpxchg.org>,
	"Laura Abbott" <lauraa@codeaurora.org>,
	"Marek Szyprowski" <m.szyprowski@samsung.com>,
	"Mel Gorman" <mgorman@techsingularity.net>,
	"Michal Nazarewicz" <mina86@mina86.com>,
	"Minchan Kim" <minchan@kernel.org>,
	"Rik van Riel" <riel@redhat.com>,
	"Russell King" <linux@armlinux.org.uk>,
	"Will Deacon" <will.deacon@arm.com>,
	"Linus Torvalds" <torvalds@linux-foundation.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Revert "mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE"
Date: Tue, 22 May 2018 17:02:57 -0700	[thread overview]
Message-ID: <20180522170257.ae5387d8717e81def908a53b@linux-foundation.org> (raw)
In-Reply-To: <20180521061631.GA26882@js1304-desktop>

On Mon, 21 May 2018 15:16:33 +0900 Joonsoo Kim <js1304@gmail.com> wrote:

> > (gdb) list *(dma_direct_alloc+0x22f)
> > 0x573fbf is in dma_direct_alloc (../lib/dma-direct.c:104).
> > 94	
> > 95		if (!page)
> > 96			return NULL;
> > 97		ret = page_address(page);
> > 98		if (force_dma_unencrypted()) {
> > 99			set_memory_decrypted((unsigned long)ret, 1 << page_order);
> > 100			*dma_handle = __phys_to_dma(dev, page_to_phys(page));
> > 101		} else {
> > 102			*dma_handle = phys_to_dma(dev, page_to_phys(page));
> > 103		}
> > 104		memset(ret, 0, size);
> > 105		return ret;
> > 106	}
> > 
> 
> Okay. I find the reason about this error.

It's getting rather late and we don't seem to have a final set of fixes
yet.  Perhaps the best approach here is to revert and try again for
4.18?