From: Markus Rechberger <mrechberger@gmail.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: LKML <linux-kernel@vger.kernel.org>, Greg KH <greg@kroah.com>
Subject: Re: USBFS Memory allocation Bug
Date: Wed, 10 Mar 2010 10:33:32 +0100 [thread overview]
Message-ID: <d9def9db1003100133wa705618ped71e146cf4c326d@mail.gmail.com> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1003092209160.29607-100000@netrider.rowland.org>
On Wed, Mar 10, 2010 at 4:13 AM, Alan Stern <stern@rowland.harvard.edu> wrote:
> On Wed, 10 Mar 2010, Markus Rechberger wrote:
>
>> On Tue, Mar 9, 2010 at 11:31 PM, Alan Stern <stern@rowland.harvard.edu> wrote:
>> > On Tue, 9 Mar 2010, Markus Rechberger wrote:
>> >
>> >> Hi,
>> >>
>> >> I just stumbled around following issue:
>> >>
>> >> [275835.163502] Pid: 14298, comm: mediasrv Not tainted 2.6.33 #7
>> >> [275835.163505] Call Trace:
>> >> [275835.163514] [<ffffffff810df7a6>] __alloc_pages_nodemask+0x5b6/0x700
>> >> [275835.163520] [<ffffffff8110c667>] alloc_pages_current+0x87/0xd0
>> >> [275835.163525] [<ffffffff810dcf79>] __get_free_pages+0x9/0x50
>> >> [275835.163529] [<ffffffff81114f2b>] __kmalloc+0x13b/0x1f0
>> >> [275835.163535] [<ffffffff813a18ef>] proc_do_submiturb+0x2ff/0x9d0
>> >> [275835.163539] [<ffffffff813a26b9>] usbdev_do_ioctl+0x6f9/0x14a0
>> >
>> > The mediasrv program tried to allocate more memory than was available.
>> > It's unfortunate but it's not a bug.
>> >
>>
>> Yes, 'unfortunate' is what bothers me about this, it can only be
>> around 198kbyte what the app can try to request (everything else will
>> fail internally).
>> The system has 4 gig ram, around 1 gig was not allocated (according to
>> free). not sure but I guess the pool where kmalloc tried to get the
>> memory from was out of memory, at least the OOM manager was not active
>> at all either and the rest of the system was more or less running
>> smoothly at this time.
>
> I suppose it's barely possible that even though 1 GB of memory was
> free, there was too much fragmentation to allocate a contiguous 198 KB
> buffer. But that seems rather unlikely (unless your machine had been
> up for a very long time).
>
> At any rate, clearly the bug, if there is one, lies in the memory
> management subsystem and not in usbfs.
>
seems like yes, but the final result of this is that mediasrv was not
killable anymore.
Shouldn't the syscall just fail if this happens?
Markus
> Alan Stern
>
>
next prev parent reply other threads:[~2010-03-10 9:33 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-09 21:09 Markus Rechberger
2010-03-09 22:31 ` Alan Stern
2010-03-09 23:32 ` Markus Rechberger
2010-03-10 3:13 ` Alan Stern
2010-03-10 9:33 ` Markus Rechberger [this message]
2010-03-10 15:04 ` Alan Stern
2010-03-10 13:57 ` Mel Gorman
2010-03-10 15:16 ` Alan Stern
2010-03-10 15:21 ` Mel Gorman
2010-03-10 15:49 ` Alan Stern
2010-03-10 15:55 ` Mel Gorman
2010-03-11 16:56 ` Alan Stern
2010-03-14 23:31 ` Andrew Morton
2010-03-15 9:36 ` Mel Gorman
2010-03-15 13:57 ` Alan Stern
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