Date: Wed, 2 Apr 2014 15:55:07 +0100
From: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
        Davidlohr Bueso <davidlohr@hp.com>,
        Manfred Spraul <manfred@colorfullife.com>, aswin@hp.com,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        "Gotou, Yasunori" <y-goto@jp.fujitsu.com>,
        chenhanxiao <chenhanxiao@cn.fujitsu.com>,
        Gao feng <gaofeng@cn.fujitsu.com>
Subject: Re: [PATCH] ipc,shm: increase default size for shmmax
Message-ID: <20140402155507.1d976144@alan.etchedpixels.co.uk>
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> Why aren't people just setting the sysctl to a petabyte?  What problems
> would that lead to?

Historically - hanging on real world desktop systems when someone
accidentally creates a giant SHM segment and maps it.

If you are running with vm overcmmit set to actually do checks then it
*shouldn't* blow up nowdays.

More to the point wtf are people still using prehistoric sys5 IPC APIs
not shmemfs/posix shmem ?

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