From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Kirill A. Shutemov" <kirill@shutemov.name>
Subject: Re: [PATCH RFCv2] mm/madvise: introduce MADV_POPULATE_(READ|WRITE)
 to prefault/prealloc memory
Date: Mon, 15 Mar 2021 16:03:53 +0300
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References: <20210308164520.18323-1-david@redhat.com>
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To: David Hildenbrand <david@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>, Arnd Bergmann <arnd@arndb.de>, Michal Hocko <mhocko@suse.com>, Oscar Salvador <osalvador@suse.de>, Matthew Wilcox <willy@infradead.org>, Andrea Arcangeli <aarcange@redhat.com>, Minchan Kim <minchan@kernel.org>, Jann Horn <jannh@google.com>, Jason Gunthorpe <jgg@ziepe.ca>, Dave Hansen <dave.hansen@intel.com>, Hugh Dickins <hughd@google.com>, Rik van Riel <riel@surriel.com>, "Michael S . Tsirkin" <mst@redhat.com>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, Vlastimil Babka <vbabka@suse.cz>, Richard Henderson <rth@twiddle.net>, Ivan Kokshaysky <ink@jurassic.park.msu.ru>, Matt Turner <mattst88@gmail.com>, Thomas Bogendoerfer <tsbogend@alpha.franken.d>

On Mon, Mar 15, 2021 at 01:25:40PM +0100, David Hildenbrand wrote:
> On 15.03.21 13:22, Kirill A. Shutemov wrote:
> > On Mon, Mar 08, 2021 at 05:45:20PM +0100, David Hildenbrand wrote:
> > > +			case -EHWPOISON: /* Skip over any poisoned pages. */
> > > +				start += PAGE_SIZE;
> > > +				continue;
> > 
> > Why is it good approach? It's not abvious to me.
> 
> My main motivation was to simplify return code handling. I don't want to
> return -EHWPOISON to user space

Why? Hiding the problem under the rug doesn't help anybody. SIGBUS later
is not better than an error upfront.

-- 
 Kirill A. Shutemov