linux-kernel - Re: scsi-mq V2

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <x49r41tyo7l.fsf@segfault.boston.devel.redhat.com>
Date:	Thu, 10 Jul 2014 16:05:02 -0400
From:	Jeff Moyer <jmoyer@...hat.com>
To:	Jens Axboe <axboe@...nel.dk>
Cc:	Benjamin LaHaise <bcrl@...ck.org>,
	"Elliott\, Robert \(Server Storage\)" <Elliott@...com>,
	Christoph Hellwig <hch@...radead.org>,
	"dgilbert\@interlog.com" <dgilbert@...erlog.com>,
	James Bottomley <James.Bottomley@...senPartnership.com>,
	Bart Van Assche <bvanassche@...ionio.com>,
	"linux-scsi\@vger.kernel.org" <linux-scsi@...r.kernel.org>,
	"linux-kernel\@vger.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: scsi-mq V2

Jens Axboe <axboe@...nel.dk> writes:

> On 2014-07-10 17:11, Jeff Moyer wrote:
>> Benjamin LaHaise <bcrl@...ck.org> writes:
>>
>>>>
>>>> [  186.339064] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>>> [  186.339065] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>>> [  186.339067] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>>> [  186.339068] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>>> [  186.339069] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>>
>>> Something is horribly wrong here.  There is no way that value for nr_events
>>> should be passed in to ioctx_alloc().  This implies that userland is calling
>>> io_setup() with an impossibly large value for nr_events.  Can you post the
>>> actual diff for your fs/aio.c relative to linus' tree?
>>>
>>
>> fio does exactly this!  it passes INT_MAX.
>
> That's correct, I had actually forgotten about this. It was a change
> made a few years back, in correlation with the aio optimizations
> posted then, basically telling aio to ignore that silly (and broken)
> user ring.

I still don't see how you accomplish that.  Making it bigger doesn't get
rid of it.  ;-)

Cheers,
Jeff
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/