From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Hans de Goede <hdegoede@redhat.com>,
Alan Stern <stern@rowland.harvard.edu>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
ldv-project@linuxtesting.org
Subject: Re: [PATCH] usb/core/devio.c: Don't use GFP_KERNEL while we cannot reset a storage device
Date: Fri, 8 Mar 2013 12:59:40 -0800 [thread overview]
Message-ID: <20130308205940.GA15806@kroah.com> (raw)
In-Reply-To: <1362761447-24643-1-git-send-email-khoroshilov@ispras.ru>
On Sat, Mar 09, 2013 at 12:50:47AM +0800, Alexey Khoroshilov wrote:
> As it was described by Oliver Neukum in commit acbe2fe
> "USB: Don't use GFP_KERNEL while we cannot reset a storage device":
>
> Memory allocations with GFP_KERNEL can cause IO to a storage device
> which can fail resulting in a need to reset the device. Therefore
> GFP_KERNEL cannot be safely used between usb_lock_device()
> and usb_unlock_device(). Replace by GFP_NOIO.
>
> The patch fixes the same issue in usb/core/devio.c.
But that's for userspace drivers, why does it matter here for them?
> All the allocations fixed are under usb_lock_device() from usbdev_do_ioctl().
I really don't want to have usbfs using GFP_NOIO as it is known for
allocating a lot of memory already. Given that no one has ever reported
a problem like this, I don't think it deserves to change, sorry.
greg k-h
next prev parent reply other threads:[~2013-03-08 20:59 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-08 16:50 [PATCH] usb/core/devio.c: Don't use GFP_KERNEL while we cannot reset a storage device Alexey Khoroshilov
2013-03-08 17:55 ` Alan Stern
2013-03-08 20:46 ` Oliver Neukum
2013-03-09 2:59 ` Alan Stern
2013-03-08 20:59 ` Greg Kroah-Hartman [this message]
2013-03-11 13:31 ` Ming Lei
2013-03-11 15:32 ` Alan Stern
2013-03-11 15:52 ` Ming Lei
2013-03-11 16:08 ` Alan Stern
2013-03-11 16:34 ` Ming Lei
2013-03-11 18:55 ` Alan Stern
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