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From: Oleg Nesterov <oleg@redhat.com>
To: Roman Peniaev <r.peniaev@gmail.com>
Cc: Ming Lei <ming.lei@canonical.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] init: fix race between rootfs mount and firmware loading
Date: Wed, 17 Sep 2014 19:59:44 +0200	[thread overview]
Message-ID: <20140917175944.GD19308@redhat.com> (raw)
In-Reply-To: <CACZ9PQXJzoczS7gN5UCFygTHrLW5Rtjew5BF-txfL=cryE331w@mail.gmail.com>

On 09/17, Roman Peniaev wrote:
>
> On Tue, Sep 16, 2014 at 1:39 AM, Oleg Nesterov <oleg@redhat.com> wrote:
> > On 09/15, Roman Pen wrote:
> >>
> >
> > Otherwise wait_for_rootfs() can return only once, the next call will block
> > forever. And perhaps it would be better to use another primitive, even if
> > UINT_MAX/2 should be enough.
>
> And why do you think completion is not good for this?
> Seems it is impossible to have so many threads on early init, which wait
> for rootfs.

Yes, but it is not only called during init? Suppose that a user does
insmod + rmmod in a loop, and the driver calls request_firmware(). This
will hang after UINT_MAX/2 iterations. Sure, this can't happen in practice,
but still this doesn't look good imho.

Oleg.


      parent reply	other threads:[~2014-09-17 18:02 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-15 14:45 [PATCH 1/1] init: fix race between rootfs mount and firmware loading Roman Pen
2014-09-15 16:39 ` Oleg Nesterov
2014-09-17 13:18   ` Roman Peniaev
2014-09-17 13:28     ` [v2 PATCH " Roman Pen
2014-09-17 17:46       ` Oleg Nesterov
2014-09-18 13:31         ` Roman Peniaev
2014-09-18 17:28           ` Oleg Nesterov
2014-09-18 13:33         ` [v3 " Roman Pen
2014-09-18 17:41           ` Oleg Nesterov
2014-09-19 12:41             ` Roman Peniaev
2014-09-19 18:03               ` Oleg Nesterov
2014-09-19 12:44             ` [v4 " Roman Pen
2014-09-19 19:45               ` Oleg Nesterov
2014-09-20 13:20                 ` Roman Peniaev
2014-09-19 21:42               ` Greg Kroah-Hartman
2014-09-20 13:18                 ` Roman Peniaev
2014-09-20 14:42                   ` Greg Kroah-Hartman
2014-09-20 15:12                     ` Roman Peniaev
2014-09-17 17:59     ` Oleg Nesterov [this message]

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