LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Alan Stern <stern@rowland.harvard.edu>
To: Oliver Neukum <oneukum@suse.com>
Cc: Jaewon Kim <jaewon31.kim@gmail.com>,
	Christoph Hellwig <hch@infradead.org>, <linux-mm@kvack.org>,
	<gregkh@linuxfoundation.org>,
	Jaewon Kim <jaewon31.kim@samsung.com>, <m.szyprowski@samsung.com>,
	<ytk.lee@samsung.com>, <linux-kernel@vger.kernel.org>,
	<linux-usb@vger.kernel.org>
Subject: Re: [RFC PATCH] usb: host: xhci: allow __GFP_FS in dma allocation
Date: Tue, 28 May 2019 10:25:12 -0400 (EDT)	[thread overview]
Message-ID: <Pine.LNX.4.44L0.1905281021120.1564-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <1559046886.13873.2.camel@suse.com>

On Tue, 28 May 2019, Oliver Neukum wrote:

> Am Donnerstag, den 23.05.2019, 10:01 -0400 schrieb Alan Stern:
> > On Wed, 22 May 2019, Oliver Neukum wrote:
> > 
> > > On Mi, 2019-05-22 at 10:56 -0400, Alan Stern wrote:
> > > > On Wed, 22 May 2019, Oliver Neukum wrote:
> > > > 
> > > > > I agree with the problem, but I fail to see why this issue would be
> > > > > specific to USB. Shouldn't this be done in the device core layer?
> > > > 
> > > > Only for drivers that are on the block-device writeback path.  The 
> > > > device core doesn't know which drivers these are.
> > > 
> > > Neither does USB know. It is very hard to predict or even tell which
> > > devices are block device drivers. I think we must assume that
> > > any device may be affected.
> > 
> > All right.  Would you like to submit a patch?
> 
> Do you like this one?

Hmmm.  I might be inclined to move the start of the I/O-protected
region a little earlier.  For example, the first
blocking_notifier_call_chain() might result in some memory allocations.

The end is okay; once bus_remove_device() has returned the driver will 
be completely unbound, so there shouldn't be any pending I/O through 
the device.

Alan Stern


  reply	other threads:[~2019-05-28 14:25 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-17 16:02 Jaewon Kim
2019-05-17 16:34 ` Matthew Wilcox
2019-05-18  1:53   ` Jaewon Kim
2019-05-20  5:56 ` Christoph Hellwig
2019-05-20  9:09   ` Oliver Neukum
2019-05-20 10:12     ` Christoph Hellwig
2019-05-20 14:16       ` Alan Stern
2019-05-20 14:23         ` Christoph Hellwig
2019-05-21  8:54           ` Oliver Neukum
2019-05-21 13:27             ` Christoph Hellwig
2019-05-21 13:11         ` Oliver Neukum
2019-05-21 14:00           ` Alan Stern
2019-05-22  6:31             ` Oliver Neukum
2019-05-22 14:56               ` Alan Stern
2019-05-22 20:47                 ` Oliver Neukum
2019-05-23 14:01                   ` Alan Stern
2019-05-28 12:34                     ` Oliver Neukum
2019-05-28 14:25                       ` Alan Stern [this message]
2019-05-23 12:32   ` Oliver Neukum
2019-05-23 16:35     ` Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=Pine.LNX.4.44L0.1905281021120.1564-100000@iolanthe.rowland.org \
    --to=stern@rowland.harvard.edu \
    --cc=gregkh@linuxfoundation.org \
    --cc=hch@infradead.org \
    --cc=jaewon31.kim@gmail.com \
    --cc=jaewon31.kim@samsung.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=m.szyprowski@samsung.com \
    --cc=oneukum@suse.com \
    --cc=ytk.lee@samsung.com \
    --subject='Re: [RFC PATCH] usb: host: xhci: allow __GFP_FS in dma allocation' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).