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From: David Miller <davem@davemloft.net>
To: bhutchings@solarflare.com
Cc: jbenc@redhat.com, netdev@vger.kernel.org, richardcochran@gmail.com
Subject: Re: [PATCH net-next] ptp: dynamic allocation of PHC char devices
Date: Wed, 10 Apr 2013 13:49:27 -0400 (EDT)	[thread overview]
Message-ID: <20130410.134927.1751916446892581975.davem@davemloft.net> (raw)
In-Reply-To: <1365615436.2581.15.camel@bwh-desktop.uk.solarflarecom.com>

From: Ben Hutchings <bhutchings@solarflare.com>
Date: Wed, 10 Apr 2013 18:37:16 +0100

> On Wed, 2013-04-10 at 12:47 +0200, Jiri Benc wrote:
>> As network adapters supporting PTP are becoming more common, machines with
>> many NICs suddenly have many PHCs, too. The current limit of eight /dev/ptp*
>> char devices (and thus, 8 network interfaces with PHC) is insufficient. Let
>> the ptp driver allocate the char devices dynamically.
>> 
>> The character devices are allocated in chunks. idr is used for tracking
>> minor numbers allocation; the mapping from index to pointer is not used, as
>> it is not needed for posix clocks.
> [...]
> 
> I don't understand why you want to dynamically allocate chunks of minor
> numbers, rather than the full range.  Unused minors don't seem to cost
> anything.

Can't multiple (unrelated) devices carve out minor space in the same
major?  Isn't that why it's designed this way?

  reply	other threads:[~2013-04-10 17:49 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-10 10:47 [PATCH net-next] ptp: dynamic allocation of PHC char devices Jiri Benc
2013-04-10 17:37 ` Ben Hutchings
2013-04-10 17:49   ` David Miller [this message]
2013-04-10 18:12     ` Ben Hutchings
2013-04-11  9:52       ` Jiri Benc

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