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From: Tejun Heo <tj@kernel.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oneukum@suse.com>,
	Bhaktipriya Shridhar <bhaktipriya96@gmail.com>,
	Geliang Tang <geliangtang@163.com>,
	"GeyslanG.Bem@Karyakshetra" <geyslan@gmail.com>,
	Masanari Iida <standby24x7@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Michal Hocko <MHocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
	Mel Gorman <mgorman@techsingularity.net>,
	Saurabh Karajgaonkar <skarajga@visteon.com>,
	linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: [RFC] usb: host: u132-hcd: Remove deprecated create_singlethread_workqueue
Date: Wed, 27 Jul 2016 15:23:08 -0400	[thread overview]
Message-ID: <20160727192308.GP4144@mtj.duckdns.org> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1607271450240.1664-100000@iolanthe.rowland.org>

Hello, Alan.

On Wed, Jul 27, 2016 at 02:54:51PM -0400, Alan Stern wrote:
> > Hmm... I didn't know the whole USB stack could operate without
> > allocating memory.  Does usb stack have mempools and stuff all the way
> > through?
> 
> No -- the USB stack does need to allocate memory in order to operate.  
> But it is careful to use GFP_NOIO or GFP_ATOMIC for allocations that
> might be on the block-device path.

Hmm... That doesn't really make them dependable during memory reclaim.
What happens when those allocations fail?

Thanks.

-- 
tejun

  reply	other threads:[~2016-07-27 19:23 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-27  9:20 [RFC] usb: host: u132-hcd: Remove deprecated create_singlethread_workqueue Bhaktipriya Shridhar
2016-07-27  9:29 ` Oliver Neukum
2016-07-27 18:00   ` Tejun Heo
2016-07-27 18:54     ` Alan Stern
2016-07-27 19:23       ` Tejun Heo [this message]
2016-07-27 20:45         ` Alan Stern
2016-07-29 13:11           ` Tejun Heo
2016-08-01 13:50             ` Michal Hocko
2016-08-01 14:20               ` Tejun Heo
2016-08-01 18:00                 ` Alan Stern
2016-08-01 18:28                   ` Michal Hocko
2016-08-02  8:06                 ` Oliver Neukum
2016-08-02  8:18                   ` Michal Hocko
2016-08-02 10:03                     ` Oliver Neukum
2016-08-02 11:34                       ` Michal Hocko
2016-08-02 11:44                         ` Oliver Neukum
2016-08-02 12:48                           ` Michal Hocko
2016-08-02 13:29                             ` Oliver Neukum
2016-08-02 19:02                               ` Tejun Heo
2016-08-02 21:26                                 ` Michal Hocko

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