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From: hooanon05@yahoo.co.jp
To: linux-kernel@vger.kernel.org
Subject: __vm_enough_memory(), OVERCOMMIT_NEVER, current->mm, kernel thread
Date: Wed, 22 Oct 2008 00:14:31 +0900	[thread overview]
Message-ID: <7123.1224602071@jrobl> (raw)


Hello all,

When sysctl_overcommit_memory is set OVERCOMMIT_NEVER,
__vm_enough_memory() refers current->mm.

For example,
# exportfs -i -o ... localhost:/tmpfs
# mkdir /tmp/w
# mount -o ... localhost:/tmpfs /tmp/w
# yes > /tmp/w/fileA

In this case, NFSD (kernel thread) calls shmem_file_write() or
shmem_write_begin() and __vm_enough_memory() is called. But current->mm
is NULL and the kernel crashes.
If a user have to set OVERCOMMIT_NEVER, where should we fix?


Junjiro R. Okajima

             reply	other threads:[~2008-10-21 15:29 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-21 15:14 hooanon05 [this message]
2008-10-21 15:46 ` __vm_enough_memory(), OVERCOMMIT_NEVER, current->mm, kernel thread Alan Cox
2008-10-21 23:10   ` hooanon05
2008-10-22  5:35     ` hooanon05
2008-10-22  8:27     ` Alan Cox
2008-10-22 11:26       ` hooanon05
2008-10-22 12:09         ` Alan Cox
2008-10-22 12:46           ` hooanon05
2008-10-22 13:37           ` James Morris

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