lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 10 Apr 2013 19:12:39 +0100 From: Ben Hutchings <bhutchings@...arflare.com> To: David Miller <davem@...emloft.net> CC: <jbenc@...hat.com>, <netdev@...r.kernel.org>, <richardcochran@...il.com> Subject: Re: [PATCH net-next] ptp: dynamic allocation of PHC char devices On Wed, 2013-04-10 at 13:49 -0400, David Miller wrote: > From: Ben Hutchings <bhutchings@...arflare.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? Only at a level above the core char device functions, e.g. misc_register() for singleton devices. Unless I'm very much mistaken, when you allocate a char device range and specify major=0 you get a dynamically allocated and previously unused major, regardless of how many minors you asked for. Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists