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Date: Fri, 27 Apr 2018 10:25:55 +0200
From: Michal Hocko <mhocko@kernel.org>
Subject: Re: [dm-devel] [PATCH v5] fault-injection: introduce kvmalloc
 fallback options
Message-ID: <20180427082555.GC17484@dhcp22.suse.cz>
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To: Mikulas Patocka <mpatocka@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>, John Stoffel <john@stoffel.org>, James Bottomley <James.Bottomley@HansenPartnership.com>, Michal@stoffel.org, eric.dumazet@gmail.com, netdev@vger.kernel.org, jasowang@redhat.com, Randy Dunlap <rdunlap@infradead.org>, linux-kernel@vger.kernel.org, Matthew Wilcox <willy@infradead.org>, linux-mm@kvack.org, dm-devel@redhat.com, Vlastimil Babka <vbabka@suse.cz>, Andrew@stoffel.org, David Rientjes <rientjes@google.com>, Morton <akpm@linux-foundation.org>, virtualization@lists.linux-foundation.org, David Miller <davem@davemloft.net>, edumazet@google.com

On Thu 26-04-18 18:52:05, Mikulas Patocka wrote:
> 
> 
> On Fri, 27 Apr 2018, Michael S. Tsirkin wrote:
[...]
> >    But assuming it's important to control this kind of
> >    fault injection to be controlled from
> >    a dedicated menuconfig option, why not the rest of
> >    faults?
> 
> The injected faults cause damage to the user, so there's no point to 
> enable them by default. vmalloc fallback should not cause any damage 
> (assuming that the code is correctly written).

But you want to find those bugs which would BUG_ON easier, so there is a
risk of harm IIUC and this is not much different than other fault
injecting paths.
-- 
Michal Hocko
SUSE Labs