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Date: Wed, 4 Oct 2017 00:51:27 +0100
From: Alan Cox <alan@llwyncelyn.cymru>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>, Christoph Hellwig <hch@lst.de>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, kernel-team@fb.com
Subject: Re: tty crash due to auto-failing vmalloc
Message-ID: <20171004005127.398be9ab@alans-desktop>
In-Reply-To: <20171003225504.GA966@cmpxchg.org>
References: <20171003225504.GA966@cmpxchg.org>
Organization: is over-rated
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> I think this patch should be reverted. If somebody is vmallocing crazy
> amounts of memory in the exit path we should probably track them down
> individually; the patch doesn't reference any real instances of that.
> But we cannot start failing allocations that have never failed before.
> 
> That said, maybe we want Alan's N_NULL failover in the hangup path too?

I think that would be best. There's always going to be a failure case
even if the vmalloc change makes it rarer. Dropping back to N_NULL fixes
all of the cases.

Alan

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Date: Wed, 4 Oct 2017 00:51:27 +0100
From: Alan Cox <alan@llwyncelyn.cymru>
Subject: Re: tty crash due to auto-failing vmalloc
Message-ID: <20171004005127.398be9ab@alans-desktop>
In-Reply-To: <20171003225504.GA966@cmpxchg.org>
References: <20171003225504.GA966@cmpxchg.org>
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To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>, Christoph Hellwig <hch@lst.de>, Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com

> I think this patch should be reverted. If somebody is vmallocing crazy
> amounts of memory in the exit path we should probably track them down
> individually; the patch doesn't reference any real instances of that.
> But we cannot start failing allocations that have never failed before.
> 
> That said, maybe we want Alan's N_NULL failover in the hangup path too?

I think that would be best. There's always going to be a failure case
even if the vmalloc change makes it rarer. Dropping back to N_NULL fixes
all of the cases.

Alan

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